How can I get the largest image possible?

[josher9]

Hi everyone...I'm new the the forums.

I recently got a Digital Rebel EOS 300 (I have two 1 gig cards and one 256 mb card). I would like to use it for a photo shoot next week. The images will be used in magazine print and outdoor (billboards, bus kings, etc.) advertising. I'll take along my trusty film camera as well as a back-up.

My question though is this:

How can I get the highest resolution (or image size) possible out of this camera. I tried a couple of test shots in RAW format and sent them to my service bureau (they do my film color seps for me) to see if the images were large enough but they said they are not.

Could downloading the images from the camera via iPhoto (mac os 10.3.9) and exporting them to my desktop for emailing cause any file reduction? Are there other settings within the camera that I haven't figured out yet? Should I be downloading the images from the camera into one of the Canon software apps that came with the camera on CD?

Any and all help or advise would be really appreciated. Thanks!

[Michael_Lambert]

The Largest Resolution you can obtain with your Digital rebel is shooting in "Raw" and leaving the images unprocessed in "Raw" the image size would be 4-6 megs depending on what you are shooting. This being said, the image size of "Raw" image is usally too big to be emailed? I belieave that the Digital rebel max size for printing is 48 inches?

Michael

[MDJAK]

For images the size you're talking about, I don't even know if my 1DSMII would be large enough. Perhaps medium format with a 22 megapixel back would be. You can probably rent one.

[Pb2Au]

You could use software like Genuine Fractals to interpolate the files to whatever you wanted... within reason. +100%, +300%...

It's not as good as Medium or Large format, but it's way easier/cheaper. It just depends on your ultimate needs.

[Vetteography]

My DReb XT pictures are 48"x32" straight from the camera and if you resample them to 300 DPI that works out to 14,400x9600 pixels.

How big do they have to be?

[tim]

Shooting RAW will give you the best quality and flexability, but only if you understand how to work with RAW. JPG will be fine so long as you don't need to manipulate it on the PC - ie print it how it came out of the camera.

Billboard prints don't need to be 300dpi, because people are so far away when they read them. Depending on the placement and distance people will be viewing it from, you might be better off with medium format.

With the 20D, you have about 3500 pixels wide. Assuming a 5m wide billboard you'll end up with about 0.7 pixels per mm - ie each pixel will be 1.4mm wide. From up close that won't look great, but from a few meters back it should look ok. I'd recommend doing a test first though, print some 6*4s or a bit larger to the same scale the billboard would have, and see if you're happy with the quality. If not, go medium format.

[puttick]

You should take a look at this CPS Newsletter article about a pro photographer using a 10D to produce 7m (23 ft) tall portraits of kids for a national charity campaign in London.

http://www.cps.canon-europe.com/articles/article.jsp?article.articleId=100300

The 10D has the same resolution as your 300D. I would suggest use the lowest ISO in good light, on a tripod, shoot in RAW (this avoids any sharpening artefacts in camera), convert with no sharpening, and "res up" the image for example in Photoshop.

Good luck

Nigel

[Bodog]

1. You need to find out from your service bureeau what size files they need before doing anything.
2. You mentioned sending RAW files to the service bureau. Don't they require Tiff or Jpeg?

[josher9]

Hey everyone...thanks for all of the feedback!

I just emailed a ".CRW" image to my service bureau which was 5.3 mbs (email size was 7.8). They'll let me know if it will work tomorrow morning. I'll post an update tomorrow.

In the mean time, if anyone has any other thoughts or suggestions, please post a reply. Your input has been very helpful and is beginning to give me confidence.

(FYI: The image was shot in RAW format and was untouched by iPhoto or PS - I used OS X's Image Capture to download from the camera and Canon's Image Browser to view.)

[jporter12]

I'm surprised to see the use of JPG instead of raw on that CPS article, after getting the impression that RAW is "the holy grail" of digital. I still plan to do some experimentation of my own to see what works best for me, as I uderstand that's where the real difference is, what works for each individual!

[tim]

I'm suprised the bureau took a RAW file - most places want a JPG or TIFF.

[Jim_T]

Your EOS produces images that are 3072 x 2048 pixels. They have no physical size until they are actually printed. The size of the image FILE in megabytes is pretty well meaningless when it comes to assessing the quality of the image.

RAW files will be around 6 Megabytes, but RAW files are compressed.... If you convert your RAW files to uncompressed 8 bit TIFF, they will be around 18 megabytes and if you save them as 16 bit TIFF, they will be around 36 Megabytes.
Despite three different file sizes, all these images have the same quality. File size is irrelevant.

If they want more pixels, you can upsample the image with your photo editor.. You can increase it to 6144 x 4096 pixels if you want.. That's 25 megapixels. Note that you gain pixels by upsampling, but not quality.. If you save this as a 16 bit TIFF, then the file will be around 150 Megabytes.

You should really find out exactly what they want and what they plan to do with your images.. Then you can give them exactly what they need.

[joeseph]

For max pixel size, you can always photo-merge several images if the perspective doesn't change.

see: http://www.tawbaware.com/maxlyons/index.html

for really great examples...

[puttick]

I too was surprised at the use of jpg images for the 7m posters in that CPS article, but it shows what can be done. My own experience is:

Using my 350d, I shoot RAW + large jpg, using parameter 2 (less sharpening).
I convert the RAW file to 16-bit TIFF with DPP.
Then open the 2 images in Photoshop and compare the 8MP jpg with the converted RAW file, there is very little difference UNTIL I use USM.
Then after sharpening (to the same perceived level of sharpness, which requires more sharpening for the converted RAW), there is considerably more fine detail in the low-contrast and shadow areas in the converted RAW image. This additional detail is retained if I then convert the 16-bit TIFF to and 8-bit jpg.

The difference between jpg and RAW for me has become worth the extra effort as prints are incredibly sharp (not over sharp, there are no artefacts visible) and very smooth. However I have not had the need or opportunity to make a 7m high poster!

[chris clements]

My DReb XT pictures are 48"x32" straight from the camera

?? Pictures don't have any 'size' straight from the camera- they're just a grid of pixels.
It's for you to choose how big you want each pixel to be on the paper.

300 per inch is accepted as optimum glossy magazine quality, but a print at 150~200 per inch is usually good enough to pass for film in most eyes.
The long viewing distance for a billboard would probably bring the realistic resolution down to no more than a dozen an inch, maybe less.

[Jim_T]

?? Pictures don't have any 'size' straight from the camera- they're just a grid of pixels.
It's for you to choose how big you want each pixel to be on the paper.




:) Exactly.. A 48 x 32 image couldn't possibly fit in a compact flash card... CF cards are only about 1 5/8 inches by 1 3/8 inches..

[blue_max]

I can speak with some authority on this as I am a graphic designer with a production background, so I hope I know what I am saying.

If you use the maximum resolution your camera will allow, you can't improve on it, so don't stress it. Good pixels are better that bad ones (good exposure, sharpness, composition). An A4 (297x210mm) sheet will require a file size (not compressed of approximately 30mb). As has been said a dpi resolution of 300 dpi is considered the industry standard (however, printing processes have allowed this to be increased to advantage). An A5 picture will be approximately half that (say 15mb). If it is of good quality, enlarging it in photoshop or similar would be ok, to a point. This depends on the subject matter – critical detail will start to go furry, but soft detail will probably be fine.

If you have a file size that is suitable for an A4 print, rest assured that it will be ok for a poster as the dots (as that is what it is made up of) are much further apart. The repro house will tell you it needs to be huge, but it will blow up much better that you expect.

Hope that helps.

Graham

[josher9]

Here is what the service bureau reported back about the RAW ".CRW" imageI sent to them last night.
Quote:
'This file is larger but looks worse. There is some kind of
pattern/posterization going on over the whole image."

Any clue as to what he may be talking about?

[Andy_T]

Looks like they couldn't convert it properly. So I assume they used the embedded JPG that has pretty low resolution.

Convert it from RAW to TIFF 16 bit (~48 MB) and send it to them again.

Best regards,
Andy

[ssim]

I think that Andy has nailed this one. I for one would never part with even a copy of one of my RAW files. That is akin to giving your customer your negative from film (or at the very least a copy-neg).

I would bet that they aren't used to recieving RAW files and had difficulty in converting it. If they are a decent sized company they will have an ftp site that you can upload a 48mb TIFF file.

[josher9]

Hey guys...here's how they replied to the suggestion that they may have inadvertently opened the embedded JPG.

"We are opening the files with Adobe Photoshop CS using the Camera RAW
plug-in. It is the only way to open the RAW file format. It does not
look good."

Do you think they are opening the file correctly? Or, could it be my settings?

(And point well taken Sheldon. It's good to be warned of that after having been used to film for so many years. Our Service Bureau isn't our client though...they are our color separation/match print vendor.)

[robertwgross]

It is for problems like this why most photographers take their own RAW file, convert it to TIF, and send that to the service bureau (if it will fit through the pipe, so to speak). If it won't fit, then convert the TIF to JPEG as a last step, after all edits are finished. Then send that to the bureau. This will minimize the chance of them reading your RAW file with something not fully intended for your camera. For example, does the bureau know what kind of camera you are using? If they do, then they might be using a good RAW conversion. If they don't, then that explains a few things.

---Bob Gross---

[josher9]

Got it! That's the key...convert it to a tif yourself (it looks great by-the-way) using Canon's File Viewer. They now have the tif and I'll get a match print color proof to review Saturday morning. Thanks everyone!
JoshT

(Don't rely on what you see of an image in File Viewer because what you see sucks. When it's converted to a Tif and viewed in PS, it will look much better.)