FAQ: enlargements & printing your photos

[tim]

Questions get asked many times every day about printing, enlargements, and dpi/ppi, this FAQ is aimed to give people basic information on printing their images. Please start a thread if you have questions, or if you'd like me to add or change something post below or PM.

If a mod could sticky this it might save people asking the questions over and over again. If it's put inside the FAQ sticky no-one will find it I bet.

dpi vs ppi
There are plenty of articles about this on the net, but here's the basics. dpi stands for dots per inch, and it's a physical measure of how many dots go on a piece of paper. We don't care about this. The output device could be a continuous tone printer, a 250dpi minilab, or a 4000dpi inkjet, we just don't care.

ppi stands for pixels per inch, this is what we do care about. There are two measures of ppi: one is just a meaningless number inside the file, one is a value calculated from the number of pixels and the print size. An image might be 3000 pixels wide, with an embedded value of 72ppi, that ppi value is irrelevant. What's important is when you choose a print size that there's enough pixels to give you the detail you want. For example if you wanted to make a 10" wide print from a 3000 pixel wide image that will give you 300ppi. Even if the embedded value's set at 72ppi it's ignored. It's just a number.

Some labs require the correct ppi and number of pixels in a file. In this case use the instructions below to give the lab what they want.

How do I change the ppi without changing the number of pixels in the image?
Hit image -> resize, uncheck "resample", enter your ppi, hit ok.

How do I create a properly sized image for printing at my lab? They want 212ppi with the correct number of pixels in the file
There's any number of ways
- For individual files get the crop tool, in the tool bar enter the width, height, and resolution you want in ppi. Use the crop tool. It will resize and set the ppi.
- For a batch you can write an action using the image -> size command, and run it using the batch commands or the image processor. If you use image processor you just need to use the "How do I change the ppi..." answer above.
- For a batch of RAW files in CS3 ACR just set the resolution using the blue link at the below the image, in the center. Then run image processor over the RAW files, setting the resolution you want in the script options. I think this will work, someone let me know if it doesn't and i'll work out another way.
- In each case save as a Q10 jpeg. Q12 is unnecessary, Q10 is as well but there's no harm except wasted bandwidth sending them to the lab.

When I open an image in photoshop it says it's 60x40" at 72ppi, is that ok?
Pay attention to the number of pixels, not the size photoshop thinks it is. The only time ppi matters is when you send it to a print firm, and sometimes not even then. If you want to change it just go to the photoshop image size command, uncheck the "resample" box, and put 300 in the resolution field.

Does my camera have a default resolution?
Maybe. It doesn't matter, it's just a number. Your software can override it easily, either in a RAW converter or in Photoshop.

Resolution & Viewing Distance
Ideally we want 250-300ppi for images that are going to be looked at closely. Most consumer labs use 300ppi, my pro lab uses 250ppi. I can't see any difference no matter how close I get. Maybe I could if I used a magnifying glass, but i'm not going to do that.

For prints 30" or above I would try to stay about 75ppi if possible, unless the viewing distance is high.

Enlargements, and "How Large Can I Print An Image?"
When you make large prints you naturally stand further away from the image, which means you can't see the fine details. Because of this you don't need as many pixels per inch for large prints.

I've made 30x40" prints from images from a 20D, which gives 83ppi, the print looks fantastic. You can't stand closer than a couple of meters and still appreciate the whole image so 83ppi is enough. If you get up really close you can see there's not huge amounts of fine detail, but it's surprisingly good. I've made a 50" print from a 12.7MP 5D ISO800 image which looks amazing.

People regularly blow up images from a 20D to make billboards. This works fine because people are quite a distance from them, often in moving vehicles. You could quite easily blow up an image to the size of the moon, and get probably one pixel per mile, but because of viewing distance it'd look fine.

What about prints on canvas?
Canvas is a very forgiving medium. 100ppi looks great on canvas.

Should I enlarge myself or let the lab do it?
If the lab can do it for no charge, I let the lab do it. They're experts. I'm not. They have expensive software called a RIP (Rasterised Image Processor) which knows how to get the best from their printer.

My main pro lab doesn't upsize for me. I do a single step upsize using the bicubic smoother in Photoshop. The old adage of "upsize in 10% increments" is from back before the bicubic algorithm, it's not necessary any more. I tried it. No difference. People often overthink things.

Should I use XYZ Software (genuine fractals etc) to do the upsize?
Nope, Photoshop does a good job. If you're not convinced get the trial version and try it for yourself. Judge by the prints, not the 100% crop, label them on the back and have someone mix them up for you. Print crops if you don't want to spend money on big prints.

I tried to print an image but they said there wasn't enough resolution. What do I do?
Upsize the image yourself in Photoshop, then send it in. See the two questions above for why this works.

Proportions (or making an 8x10"print)
Images from Canon DSLR cameras always have the 3:2 ratio - eg 3504 x 2336 is 3:2 on a 20D. If you print this 10" wide that means it will be 6.66" high, or conversely if you print it 8" high it will be 12" wide. If you want a 8x10" print (or any size that's not a 3:2 ratio) you need to crop the image, which will discard pixels to make it the shape you want. Get the crop tool, enter 8in and 10in in the toolbar (or vice versa), drag the crop tool over the image, the hit enter or double click. If you try to leave this to the lab they'll crop where they think it should be, or worse, they'll do it automatically and might cut off an important part of the image. NB: baby cameras usually have other ratios, usually 4:3 or occasionally 16:9.

The only other solution is to use the image -> canvas size command to add black or white edges to the image. The advantage is you can see the whole image, even though it has borders.

How do I size images correctly for a 6x4" print (or other sizes)
First work out the ppi required by your lab - it's usually 300 but for example my lab wants 250ppi, and some machines like 400ppi. Multiply this number by the longest side, in inches, so 300ppi * 6 inches = 1800 pixels. If you wanted 18 inches and 250ppi that's 4500.

Choose file -> scripts -> image processor, enter this number into BOTH boxes, choose your directory of images, set an output directory (or save to same directory) and hit go. Note if you save to she same directory it'll go into a subdirectory and use the same filenames. The "convert to sRgb" tick box is a good idea if you're not sure what you're doing with color.

Also here's a small mathematical bitty. 300 pixels / inch * 6 inch = 1800 pixels inches / inch = 1800 pixels. The inches / inches cancels out, just like 1/1 does. Isn't maths great! ;)

NB: this relies on your images already having the correct ratio. Read above or below for more, but dslr images are 3:2, same as a 6x4" print. 8x10"/5x7" prints require cropping, which is a manual task.

Should I send images to my lab at the right ratio or with the correct number of pixels?
i.e. for a 5x7" print should I send in a 1500x2100px file or will a 4000x5600 file be ok?
You should always sharpen after your final resize step, so the 1500x2100px file is best, plus it's smaller and will take less time to send in. In the end it'll make little difference though.

Noise reduction
Noise reduction is also detail reduction, so I don't use it. If you really must try to mask it so you only do noise reduction in the shadow areas.

Sharpening
I'm not an expert in this. I once sharpened a 20x30" print so it looked good on screen, but the print was horrible so I had to have it redone. I sharpened some 8x12" prints for a customer, they returned them because it emphasized flaws in the skin. I sometimes apply very mild sharpening, but often I don't sharpen at all - except what my RAW converter does by default.

JPG or TIFF for printing
The final step before sending an image to the lab is to save it as a JPEG. TIFF is unnecessary, JPEG Q12 is lossy but so close to lossless you'll never know it. I've made all my 30" and 40" prints from a JPG. Q12 isn't even necessary, Q10 is fine, but I use Q12 because I can. This thread (http://photography-on-the.net/forum/showthread.php?t=210995) shows what happens when you open, modify, and save a JPG a dozen times.

Recommend Labs
For large prints I've used Elco (http://www.elcocolor.net/index.php/Poster-Special.html), the quality's fantastic and the prices are great. I've heard mpix (http://www.mpix.com) is good, they're a division of Millers pro lab (http://www.millerslab.com/). WHCC (http://www.whcc.com) is also meant to be a good pro lab, as is Pro DPI (http://www.prodpi.com/). Really printing's not that hard, and it's cheap, so just give it a go. In the UK try Loxley Color (http://www.loxleycolour.com/) if you need a pro lab.

Should I use RGB or CMYK?
CMYK is only used for commercial offset printers, not photo printing companies. Commercial printers can convert sRgb to CMYK for you, therefore you should always use CMYK unless your specific print firm tells you otherwise.

Conclusion & Recommendations
Overall I recommend people stop thinking and worrying so much and just print their images. Prints are cheap. Crop it and print it smaller if you want to. As with most things in photography the rule of "try it yourself and make up your own mind" is the best way to approach things.



Keywords (just in case anyone actually uses the search): large, big, enlarge, print, printing

[Damo77]

Great thread, Tim.

Perhaps you could mention the whole proportions thing, because we seem to see a lot of "my 2:3 photo has its ends chopped off when printed 8x10, oh woe is me" threads.

[tim]

Good idea, thanks Damo, that's done :)

[Damo77]

Remarkably concise - well done!

No luck in getting it stickied, eh?

[tim]

Ta. Nah it doesn't seem to be stickied, but I think people will link to this when people ask a question rather than go through the typing all over again. Too many stickies in this forum already apparently.

Suggestions for changes/additions always welcome.

[Lester Wareham]

Good FAQ Tim.

[shooterman]

Great FAQ. Now I know why Walgreen's scalped my wife and cut off her feet.

[Curtis N]

Excellent post, Tim.Images from the camera always have the 3:2 ratio For the benefit of our P&S shooting brethren, you may want to clarify this by writing, "DSLRs produce images with a 3:2 ratio and most P&S cameras produce images with a 4:3 ratio."

Or something to that effect. :D

[tim]

Thanks Curtis, and done.

Great FAQ. Now I know why Walgreen's scalped my wife and cut off her feet.

Heh that one took me a minute!

[brettzwo]

If I had a full res 3456 x 2304 image and wanted an 8x10, should I crop or adjust the ppi first or does it matter?

When I adjusted ppi first, it shrunk it to the 10X6.66 size. Then, when I went to make it a 10X8 it gave me some warning that it would be changing something about the photo. Will doing it in this order change the quality of the photos or does it matter if I crop or adjust ppi first?

Thank you,

-Brett

[canonpink]

Yeah, I agree with your take on sharpening. Most customers are happy if they can simply recognize what is in the photo, much less whether it is perfectly sharpened. I need to relax myself on being so picky on sharpening people.

I think the photoshop guys (i.e. NAPP) have created almost a subculture on sharpening images that any newcomer gets obsessive quickly over the concept.

Architecture and other detail oriented photos are another story obviously.

[tim]

If I had a full res 3456 x 2304 image and wanted an 8x10, should I crop or adjust the ppi first or does it matter?

When I adjusted ppi first, it shrunk it to the 10X6.66 size. Then, when I went to make it a 10X8 it gave me some warning that it would be changing something about the photo. Will doing it in this order change the quality of the photos or does it matter if I crop or adjust ppi first?

Select the crop tool, put "10 in" in the width (or height if it's portrait), "8 in" in the other field, and put 300 (or whatever ppi you want) in the resolution field. Drag the crop tool over the image and double click. You've then cropped and set the ppi at the same time.

[spcalan]

So if I have a file, that 100% of the uncropped file must be contained in final print size.
The only option is to make the canvas size to 8x10, 5x7, and then basically put a frame around it?

Any samples of this, or workflow in CS2?

[tim]

So if I have a file, that 100% of the uncropped file must be contained in final print size. The only option is to make the canvas size to 8x10, 5x7, and then basically put a frame around it?

Any samples of this, or workflow in CS2?

If it's not a standard ratio then yes, pad it using black or white. The way to do this is using the image -> canvas size command in photoshop. If you need more detail let me know and i'll try and write it out.

[Vortex99]

Thanks for clearing that up for me...

[Swift]

It might not get stickied but it could be linked to in the sticky FAQ Read first thread.

[tim]

It is already - you didn't read it did you? :p :D

[GovMule]

Tim,
Thanks for the tip on printing 8 x 10. I was going mad trying to size an 8 x 10 (kept going to 6.xx),and printed on Ilford paper no less.

[deletedpenguin]

Wonderful write up. I'm sending a few photos to the printer for the first time, and this has helped tremendously. Thank you.

Onto another topic though, can you recommend a printer in Oz? I've been looking into Digital Works in Melbourne. They seem pretty good, and have been recommended by a few others.

[tim]

Onto another topic though, can you recommend a printer in Oz? I've been looking into Digital Works in Melbourne. They seem pretty good, and have been recommended by a few others.

Happy to have helped :)I use Nulab in Melbourne for some of my orders, even though i'm in New Zealand, they're great.

[eddarr]

Tim I can understand how the quality of a print shops software and printer are able to produce larger photos from lower resolution files. But how does that affect printing at home with a standard inkjet printer?

I ran a test using a jpeg large/fine image and a Canon IP4300 printer.

I opened the file and resized the image to ?x8" at 72 ppi using bicubic smoother. Then cropped the image down to 10" x 8" still at 72ppi and printed the image.

I reopened the file and resized the image to ?x8" at 300ppi using bicubic smoother . Then cropped the image down to 10" x 8" still at 300ppi and printed the image.

The difference between the two photos is dramatic. Even my little 4300 printer, which is a good printer but not even close to the best, gives a warning if you try to print anything at less than 220 ppi.

Do we need to treat the files differently depending on whether it will be printed from a home based inkjet or by a print shop? Or does it still not matter?

[tim]

You misunderstood my original post. The number of pixels is what matters, not the ppi. In your 72ppi image (assuming it was 12x8) you had 864 x 576 pixels = 0.5 megapixels. With 12x8 at 300ppi you had 3600 x 2400 pixels = 8.6 megapixels. That's why your prints look so different. If you simply change the ppi value without resampling the image (ie turn off the resample checkbox in the image size dialog) then print them 8x12 the images will look identical.

[number six]

Tim, I have a question I haven't seen asked before: why?

Why is that 72 dpi (not ppi, usually) in there anyway? Is it really part of the EXIF?

I don't see it in the shots from my DSLR, as viewed by Exifer or FastStone. FastStone does show print size at 180 PPI, though.

It looks to me that editing software inserts the 72 dpi or ppi figure.

BTW, 72 PPI is about what you'd see on a 19" monitor (14" horizontal) viewing at 1024 X 768.

So where does that pesky 72 figure come from, and why?

Enquiring minds want to know! :lol:

-js

[tim]

I guess 72ppi is because Canon decided they should set it to something rather than leave it empty. It's irrelevant. I don't shoot JPG so i've never looked at what it does, I set the PPI in my RAW converter. 72 is the traditional value that PC screens use I think.

[JNeumann54]

72dpi is there because that is the standard for web browsers...

[In2Photos]

72dpi is there because that is the standard for web browsers...
Actually I believe it is the standard for monitors, specifically most LCDs (although some montiors use 96 PPI).

But really it does not matter. Here is some great info as well:

Say no to 72 dpi (http://www.scantips.com/no72dpi.html)

[number six]

But is that number really in the EXIF from the camera? I don't see it with any of my photo viewing programs.

Here's the EXIF from a recent shot, direct from the camera, as shown by Canon File Viewer Utility:
File Name
IMG_4916.JPG
Camera Model Name
Canon EOS DIGITAL REBEL
Shooting Date/Time
11/22/2007 6:06:52 PM
Shooting Mode
Aperture-Priority AE
Tv( Shutter Speed )
1/200
Av( Aperture Value )
8.0
Metering Mode
Evaluative
Exposure Compensation
0
ISO Speed
800
Lens
18.0 - 55.0 mm
Focal Length
55.0 mm
Image Size
3072x2048
Image Quality
Fine
Flash
On
Flash Type
External E-TTL
Flash Exposure Compensation
0
Red-eye Reduction
Off
Shutter curtain sync
1st-curtain sync
White Balance
Auto
AF Mode
One-Shot AF
Parameters
Contrast +1
Sharpness +1
Color saturation +1
Color tone Normal
Color Space
sRGB
File Size
3214KB
Drive Mode
Continuous shooting
Owner's Name
Strappe
Camera Body No.
1360435739

So I guess the 72 PPI is inserted by Photoshop. Yes? No?

-js

[Hermeto]

I guess so, yes.
Note that by default, ACR sets resolution to 240ppi.

[tzalman]

So I guess the 72 PPI is inserted by Photoshop. Yes? No?

I guess so, yes.
Note that by default, ACR sets resolution to 240ppi.

I'm not so sure. This got my curiousity going so I examined the Exif in several programs; DPP, Breeze Browser, Opanda IExif and Dalifer Lite, an Exif reading utility. The results were varied.
1. RAW files: DPP and BB showed nothing about resolution. Dalifer showed different things for the 40D and the 350D. For both cameras it showed the sensor resolution (4438.65 on x axis, 4445.97 on y for the 40D). For the 350 it also showed X Resolution - 72 and Y resolution - 72 for both the main image and the embedded jpg thumbnail. For the 40D it showed X Resolution - 72 and Y resolution - 72 for the embedded jpg only. Opanda does not read RAW
2. Jpgs from the camera: DPP, BB and Dalifer as above, except that for the 40D as well as the 350D Dalifer shows 72 for both the main and the thumbnail images. Opanda shows "X Resolution - 72, Y Resolution - 72", both cameras.
3. Embedded jpg extracted from the RAW by BB: DPP and BB show no resolution figure. Dalifer and Opanda show 240 (!?). The number was apparently changed by BB.

I HAVE TOO MUCH FREE TIME.

[tzalman]

Actually I believe it is the standard for monitors, specifically most LCDs (although some montiors use 96 PPI).


From what I have read, it was the standard for TV screens back in the '60s when the EXif standard was first formulated. I don't think it applies to either CRT or LCD monitors.

[number six]

From what I have read, it was the standard for TV screens back in the '60s when the EXif standard was first formulated. I don't think it applies to either CRT or LCD monitors.

PPI doesn't apply to NTSC TV, for the simple reason that horizontal data is analog, not digital. There are no dots horizontally. Each line is a continuous sweep.

The NTSC standard for vertical resolution is 525 lines interlaced - 262.5 lines in one field, 262.5 in the next. The two fields refresh at a 30 Hz rate.

-----------

I notice that Paint Shop Pro defaults to 180 PPI.

A point nobody has mentioned, that I've noticed: DPI means nothing on an inkjet printer, either. Well, not exactly nothing - but it's fixed. My cheap (but surprisingly high quality) Canon PIXMA 4000 has 1000 DPI, as I recall. That's the number of ink dots per inch.

-js

[silvex]

Actually I believe it is the standard for monitors, specifically most LCDs (although some montiors use 96 PPI).

But really it does not matter. Here is some great info as well:

Say no to 72 dpi (http://www.scantips.com/no72dpi.html)

Link is broken.

[silvex]

Conclusion & Recommendations
Overall I recommend people stop thinking and worrying so much and just print their images. Prints are cheap. Crop it and print it smaller if you want to. As with most things in photography the rule of "try it yourself and make up your own mind" is the best way to approach things.

Keywords (just in case anyone actually uses the search): large, big, enlarge, print, printing

This probably saved me about 2-3 years of learning! Thanks! Excellent writting. Maybe we all should add our experiences with print labs in our countries.

[cyrillo07]

Tim, with the technique of changing the ppi without changing the number of pixels, it did not work for me.

I tried this with the images that i submitted before but was rejected coz of less than 300ppi, still it was not accepted.:cry:

[airfrogusmc]

You need to get a program like Genuine Fractals if your interested in quality. I have a very good friend that the head of the photography program ant a local college and teaches basic thru advacened photoshop. He is the one that put me onto it and it makes a HUGE difference. I have to work with professional printers all the time and so does my wife and we have to deal with these issues. You can bump the size in photoshop but what happens is the info is not there so photoshop trys to fill in the areas by creating its own pixels. This degrades the image. Genuine Fractals is a program that works as a plug in and is designed to bump up image size without allot of loss.
http://www.ononesoftware.com/detail.php?prodLine_id=2 (http://www.ononesoftware.com/detail.php?prodLine_id=2)
Don the photography professor thats a good friend of mine has his classes bump prints up in photoshop and then using GF. You can see a major difference. Proper tool for the job.

[tim]

Tim, with the technique of changing the ppi without changing the number of pixels, it did not work for me.

I tried this with the images that i submitted before but was rejected coz of less than 300ppi, still it was not accepted.:cry:

You probably needed to change the number of pixels. Places that you submit work to usually want 300ppi and a minimum number of pixels.

You need to get a program like Genuine Fractals if your interested in quality. I have a very good friend that the head of the photography program ant a local college and teaches basic thru advacened photoshop. He is the one that put me onto it and it makes a HUGE difference. I have to work with professional printers all the time and so does my wife and we have to deal with these issues. You can bump the size in photoshop but what happens is the info is not there so photoshop trys to fill in the areas by creating its own pixels. This degrades the image. Genuine Fractals is a program that works as a plug in and is designed to bump up image size without allot of loss.
http://www.ononesoftware.com/detail.php?prodLine_id=2 (http://www.ononesoftware.com/detail.php?prodLine_id=2)
Don the photography professor thats a good friend of mine has his classes bump prints up in photoshop and then using GF. You can see a major difference. Proper tool for the job.


This is a valid position, something people need to look at themselves using sample versions of software to decide. I personally don't see a need for GF. Each to their own, and i'd rather this thread didn't turn into a PS vs GF thread.

[airfrogusmc]

Its not they're two very different tools.

[cyrillo07]

[quote=tim;4694691]You probably needed to change the number of pixels. Places that you submit work to usually want 300ppi and a minimum number of pixels.

I'm using Adoramapix Tim. They are requiring only the resolution of at least 300ppi, but still the largest that i can print is only 8X10.

[tim]

Best start a thread rather than pollute an FAQ with questions.

[ANTLRZ]

maybe i repeating things here,sorry if thats the case,i took some pictures of a wrestling team,individual pictures,lots of people ordered 8x10 pics,when i go to print them are you saying there is no way to get the whole pic without cutting top or bottom? i even left my photos uncropped from my camera to CS3 with alot of room round subjects and it is still cutting off feet, driving me nuts...HELP...also i read your thread i put the 8 and 10 in toolbar and recropped, i wanna know if there is a way to resize teh WHOLE PICTURE as is ?

[tim]

Nope, you can't print the whole picture on an 8x10 sheet without either cropping the image, or adding black or white bars at the top or bottom.

Please ask questions on new threads, not on the FAQ thread.

[JDB]

You can resize a photo straight out of the camera to fit an 8x10 print without cutting anything off the top or bottom, but you'll have blank space on the sides.

[silvex]

Genuine Fractals is a program that works as a plug in and is designed to bump up image size without allot of loss.
http://www.ononesoftware.com/detail.php?prodLine_id=2 (http://www.ononesoftware.com/detail.php?prodLine_id=2)
Don the photography professor thats a good friend of mine has his classes bump prints up in photoshop and then using GF. You can see a major difference. Proper tool for the job.


WOW! that is a plug-in camera makers don't want you to see. I just D/L the demo to give it a ride.

[michael_]

the JPEG TIFF for printing is handy as i have always been giving TIFF and well yeah 400mg files are just to much

[PhotosGuy]

Should I enlarge myself or let the lab do it? Even a pro lab can turn out crappy prints. Test prints can help keep track of what they're doing: at the bottom of...
http://www.gballard.net/psd/srgbforwww.html

Costco & Sam's Club Digital Prints (http://photography-on-the.net/forum/showthread.php?t=123887) Post #10 & #18.

Costco Printing (http://photography-on-the.net/forum/showthread.php?t=81122)

What's the best on-line print lab?? (http://photography-on-the.net/forum/showthread.php?p=2556147)

Have you used online printing?? (http://photography-on-the.net/forum/showthread.php?t=290192)


Canada:
Canadians - what photo lab? (http://photography-on-the.net/forum/showthread.php?t=272080)

[Bobster]

So where does that pesky 72 figure come from, and why?
blame Apple and the original mono 9in Mac..

[PhotoRook]

Bookmarked this beast. Thanks a bundle.

[jde95tln]

also bookmarking this one.. Thanks for the info!

[gooble]

As soon as I feel like I've got all the junk down about printing I run into something that befuddles me.

Ok, so I send my pics off to be printed by a pro lab. I've sent pictures off to be printed by them numerous times and I have them done as self-managed, meaning they do not adjust anything but print them as I have given them to them and this has worked out fine.

Apparently they prefer, and I quote "300 dpi" (doesn't dpi only have relevance to printing? - maybe they meant or said dpi and I missed it, and you can't set dpi on the image - can you?) images set to the dimensions I want printed. Well, in the past I've not really worried about this and have had great prints.

The last submission I tried to set them how they wanted. I sent in some 40D images, original resolution 3888x2592 cropped for 8x10 which would leave 3240x2592 pixels. Since you can't set dpi (see above) I set them to 300 ppi which if you left 'resample' checked would make the image 10.8x8.6 inches so if you let it resample it actually will throw a small amount of pixels away. Is there any sense to this?

I want all the pixels to appear on the image so why doesn't the ppi float? So if the cropped 8x10 image is 3240x2592 that makes it 324 ppi and that's it?

[Damo77]

Yes, they certainly mean ppi. The two terms are used interchangeably, even though it's technically incorrect to do so.

Yeah, send 'em 324ppi if you want to. Nobody will be able to see any difference.

[tim]

As said in the first post of the thread please start a thread to ask questions. Tip: use the crop tool with size and resolution set.

[DAMphyne]

Select the crop tool, put "10 in" in the width (or height if it's portrait), "8 in" in the other field, and put 300 (or whatever ppi you want) in the resolution field. Drag the crop tool over the image and double click. You've then cropped and set the ppi at the same time.

I know this is an old thread, but it is a matter that continues to bring questions.
If you set the PPI when you use the crop tool, doesn't that automatically up-size or downsize the file.
I always leave the PPI blank, then resize by using the 'Image size' and turn on the re-sample image box.
This allows me to determine how much I have changed the file.
Just a thought.

[Damo77]

The only advantage that brings is the ability to choose the method of resampling (eg Bicubic Smoother, etc). Otherwise, I assume the crop tool resamples using the method that's set in Preferences.

For the time it saves me, I'm completely happy to just let the Crop tool do my resampling for me. But if the two-step process works for you, then go for it.

[DAMphyne]

I agree with the time saving by using the crop tool, but print quality isn't only determined by making the file at a certain PPI, but also the amount of enlargement.
A person can crop a small part of the image, make it 300 PPI, and assume that good quality follows automatically. I just want to suggest another method to be aware of the amount of up-sizing.

[photography by trish]

very informative tim! always love reading your comments..

[tim]

Great! :) Hey does POTN have a "fans" feature" ;)

[photography by trish]

no but i just learned that there's measurebators! but i think the place is taken this month by robert. maybe next month tim...

[rewyanc2k]

could you post a workflow for creating an 8 x 10 with borders so i don't have to crop my pictures?

[René Damkot]

could you post a workflow for creating an 8 x 10 with borders so i don't have to crop my pictures?

What software?
In Photoshop:


Open the image.
Tweak as you would normally do.
Save as "filename_edit.psd" (or jpg, or whatever you prefer).
Flatten the image (if it isn't flattened already)
Duplicate the background layer. Fill the bottom layer with white.
Then go Image > Canvas Size. Set 8x10", use white as background color.
(You might get an error the image is bigger, and some clipping will occur: that's okay)

Hit "F" to go to full screen mode if you weren't already. Make sure the image fits the screen.
Click the top layer, and hit Cmd(Ctrl)+T (free transform).
Hold shift, and drag the corners of the image inward, to get the image to fit the paper like you want. Holding Alt as well will transform using the centre point as "anchor".

You now have a 6x9" photo on an 8x10" document, with a white border...

You can drag the top layer (the photo) to wherever you want, to get the border like you want.
http://img.skitch.com/20081024-gye3in31t1i1fhttd26hqc3g2p.jpg

[DonJuanMair]

the only thing i dont like is that the border is not equal

http://i84.photobucket.com/albums/k21/DonJuanMair/AbandondedHouse-1.jpg

i wish it could be

[Methodical]

Thanks for the info.

[Methodical]

could you post a workflow for creating an 8 x 10 with borders so i don't have to crop my pictures?


Here's a thread that has what you may need:
http://photography-on-the.net/forum/showthread.php?t=477194

[Karl Johnston]

I've been hunting for an idea on how to not crop out parts of the photo when cropping certain sizes. Never thought to use the border tool, thanks.

[Dooms_day]

Ive always wondered what the embeded resolution in ppi in photoshop was for, i find it completely useless unless you print directly from photoshop

[tonylong]

Ive always wondered what the embeded resolution in ppi in photoshop was for, i find it completely useless unless you print directly from photoshop

It's a required Exif tag, so something has to be there, although for most purposes (viewing, Web use, etc) it does not have a practical use.

However, the reason it is required is that some printing jobs, such as commercial/offset print jobs, often have ppi requirements.

The other use that people have for ppi is when resizing an image with resampling to, say, ensure a particular ppi at a given print size. This can help if, for example, you want to enlarge an image for a given print size and then apply some "output sharpening" at that particular size with full pixel density. This won't increase the native resolution of the image but can help you to visually try to increase the contrast of details that may get "smudged" in the enlargement process.

[Methodical]

Again this is excellent info as I have begun printing my own photos using Epson R19

[scaning]

From Canon Image Gateway,
http://www.cig.canon-europe.com
on using a Canon printer.


The Relationship Between the Original Data and Printer Resolution

Mastering the Optimal Resolution Settings for Your Printer

Just as the digital camera's image sensor has resolution, so does the printer. The printer's resolution is expressed in terms of dpi (dots per inch), the number of dots that can be arranged on the page in a single inch. The printer driver's role is to convert the resolution of the image data to the optimal resolution for the printer and transfer it.

For example, if the printer has a print resolution of 4800 × 2400 dpi (the scanning direction of the print head × the paper-feeding direction of the paper), it will be desirable to have a high-resolution setting that can also be multiplied by a whole number to equal 2400 dpi: for example, resolutions such as 200 dpi, 300 dpi, or 400 dpi.

[It doesn't say anything about having decimals in the DPI/PPI setting to achieve the whole number thing]

If you were to print with data of a different resolution than that, the remaining fraction would end up being rounded up or rounded off by the printer driver. This could cause an unnatural jaggedness or coarseness to occur in finely detailed parts of the image, even if it was high-resolution data. At times like that, you will need to readjust the resolution settings in your photo retouching software.

[image from the article]
430520The shortcut to achieving high-quality printing results has to do with choosing the optimal resolution settings for the printer. The resolution for image data on digital cameras is 72 dpi in default settings. This is changed to the optimum value for the printer at the time of printing. You can also use photo retouching software to make changes to resolution settings.

How Resolution Settings Affect Print Quality
Using Photoshop for example, change the settings under Document Size in Image Size on the Image menu. At times when print quality is of great importance, however, it is not advisable to change the resolution of the image data. Clear the checkbox for Resample Image, and then you can employ one of the following methods:

• Change the resolution (the print size will change)
• Change the width and height (the resolution will change)

Recommended values will be above 300 dpi to give priority to photo quality, and 400 dpi for landscape photos that require a particular fineness of representation.
With this method, however, both the print size and the resolution end up being incomplete. When you really want to make full-page printouts on A4-size paper, you will need to round the resolution down to a value that can be multiplied by a whole number to equal 2400 dpi, or adjust the resolution through resampling (using the bicubic method).

[Skip a table of "Relationship Between Digital Camera Image Sizes and Print Resolution" and some examples of dpi/ppi prints and use of Canons "Image Optimizer".
They recommend "image optimizer" when you can’t achieve the whole number thing]

The Fact that High Resolution High Image Quality
As you can tell from comparing the photos above, [the images are terrible small and quality is appalling, no one can see any significant difference] even if you perform image resampling in photo retouching software, raising the resolution is more effective at enhancing the ability to depict detail. If those resolution values cannot be multiplied by a whole number to equal the print resolution, though, it will end up causing coarseness in the image. For the resolution best suited to printing, a value over 300 dpi that can also be multiplied by a whole number to equal the resolution of the printer (2400 dpi, for example) is desirable. When you have a value such as 360 dpi that cannot be multiplied by a whole number to equal 2400 dpi, you can turn "Image Optimizer" to On, as when you have insufficient resolution such as 200, or there may be times when daring to raise the image

I don’t know why they persist on talking about DPI when they refer to PPI in Photoshop.

This is the link to the article:
http://www.cig.canon-europe.com/pe/f/proposal.do?o=536879193&f=link_s&ac=no
but I believe you have to be logged in, I’ll guess " Canon Image Gateway" is an European thing for those who have a Canon camera, printer or other image device.

I don’t really know if it makes any difference, I have a Pixma IP4300 and simply have adjusted the print size and let the PPI be whatever, as long as its presumably sufficient which I’ll guess is 240 PPI and above. So far it seems looked OK but I probably not looked close enough. ;-)

[scaning]

According to this article you are stuck with the PPI numbers below, on a 2400 dpi printer, if you don’t want to use decimals:
2400 ÷ 1 = 2400 ppi
2400 ÷ 2 = 1200 ppi
2400 ÷ 3 = 800 ppi
2400 ÷ 4 = 600 ppi
2400 ÷ 5 = 480 ppi
2400 ÷ 6 = 400 ppi
2400 ÷ 8 = 300 ppi
2400 ÷ 10 = 240 ppi
2400 ÷ 12 = 200 ppi
2400 ÷ 15 = 160 ppi
2400 ÷ 16 = 150 ppi
2400 ÷ 20 = 120 ppi
2400 ÷ 24 = 100 ppi
2400 ÷ 25 = 96 ppi
2400 ÷ 30 = 80 ppi
2400 ÷ 32 = 75 ppi

[Bobster]

I don’t know why they persist on talking about DPI when they refer to PPI in Photoshop.
because when dealing with printing, its always been DPI (the printer prints dots on a page, not pixels)

[tonylong]

Digital printing and digital imaging grew up together, and naturally these terms have gotten confused. But look at the specs of digital printers, and they define dpi as something different than the ppi in a digital printer. The dpi figure is how many little globs of ink get sprayed by the nozzels on the paper, the ppi is how much discrete detail the image contains. They work together in a print, but the DPI is not directly related to the PPI of the image -- in fact, the printer driver or firmware will take whatever the image offers (300 PPI, 150 PPI, 72 PPI) and resample it to what it needs to print, and then will print according to the DPI that the printer supports. A 300 ppi print may print at 4800 DPI, and a 150 PPI print will also print at 4800 PPI with the same printer and settings. The DPI stays the same even though the PPI (and quality) is less.

[René Damkot]

because when dealing with printing, its always been DPI (the printer prints dots on a page, not pixels)

Yeah, but about half the times the article says "DPI" it should have used ppi ;)

[scaning]

I’ll guess the recommendation to have the image in PPI that divided with the paper-feeding direction number result in a whole number is probably to avoid problems similar to how a scanner works.

The smaller number in scanner resolution is the optical resolution "horizontal" and the larger is the possible positioning of the carriage stepping motor. If it can move 1/2400 steps per inch it will move 8 steps a time when scanning at 300 ppi/dpi, if you scan at 250 ppi/dpi it will need to move 9,6 steps but it can’t do that and at some pixel rows it have to move 9 steps others 10 steps.

[tim]

Yeah, but about half the times the article says "DPI" it should have used ppi ;)

If you look closely a lower case p is just a d rotated by 180 degrees, so the answer is obvious - there are a lot of rotationally dyslexic people around ;)

[THE TROOPER]

Thank Tim this is a great help to me. Magic! :)

Ian

[S2K.OGRAPHY]

this is a great thread thanks

[René Damkot]

If you look closely a lower case p is just a d rotated by 180 degrees, so the answer is obvious - there are a lot of rotationally dyslexic people around ;)

That's IT!!!! :lol:

I’ll guess the recommendation to have the image in PPI that divided with the paper-feeding direction number result in a whole number is probably to avoid problems similar to how a scanner works.

Recommended for Epson: 720 (or 360) ppi, for Canon printers: 600 (or 300) ppi.

[iFloyd]

read this as im still learning how to print--awesome thread! i really feel this should be stickied

[tim]

It is sticked, within the FAQ thread. If everything was sticky the whole first page would be full of faq threads.

[Downs Photography]

is wallet 2.5 x3.5 for printing? thx guys

[tonylong]

is wallet 2.5 x3.5 for printing? thx guys

Maybe you can take another stab at this question -- what exactly are you trying to do or find out?

[BoneJj]

Maybe you can take another stab at this question -- what exactly are you trying to do or find out?
It sounds like he's is trying to find out what the "wallet" size actual size is. Personally a quick answer would be to grab a ruler and pull out his wallet and measure what he has in there.

But then again if you are like me you don't have photos in their wallet.... then it's a little hard.

[tim]

You can subscribe to a thread using the thread tools drop down just above and to the right of the top post on a page. You can bookmark using your browser. The FAQ's updated occasionally, but the only thing added to the end is posts like these.