5x7 print question

I am in the process of sending some photos to be printed.
When I use lightroom and format the photo for a 5x7 I wonder in the FILE SETTINGS what size to choose.
Last year I did send my 5D2 jpegs full resolution and it was a little heavy for the sharing.
So this year I was wondering if I could limit the size lets say to 5000K or something like that.
Any advice would be greatly appreciated.

thx

5000Kb for a 5X7 should be OK. Even 2000Kb would probably work. Try one of each & see what you think.

thx,
Well I got to know and not really try, cause i am sending a big batch of pictures to be printed.
It will cost me apprx $50 so I dont want to loose to much money on this contract.

the difference is that if I leave it full res its apprx 10 megs.
If I resize it to 5000K its apprx 4megs.

sega62 wrote in post #17322313
thx,
Well I got to know and not really try, cause i am sending a big batch of pictures to be printed.
It will cost me apprx $50 so I dont want to loose to much money on this contract.

You want to be near 300 pixels per inch if possible, but you can go smaller. I'm not making the connection between resolution and it somehow costing you extra money though.

No matter what you send them the lab will resize your images to 300 ppi (almost all labs now use printers that require 300 ppi input, although there are some older machines that need 250 ppi). For a 5x7 inch print that is (5x300) X (7x300) pixels. 1500 x 2100 pixels. You have two options, do the resize yourself in LR or let the lab do it. Personally I prefer to do it myself because my experience has been that LR resizing is at least as good as the very best labs and better than some.

However, I should add one qualifier: All my experience with lab printing has involved much bigger prints, 20x30 or 26x39 inches, where the resizing is enlarging and quality differences more visible. Up to 13x19 I print at home where the choice is LR vs. Microsoft's resizing.

Nevertheless, if I were outsourcing small prints, I would still choose LR. Why send bigger files than necessary?

What does 2100 pixels on the long side and 80% quality get you (approximately) for file size? Actual size in megabytes will also depend on things such as how noisy the image is. If 2100 and 100% Quality works for you then just go with that.

ok Thanks guys.
Really appreciated.

Andy

I generally print at 16"×12" and my 4800×3600 pixel images from LR at 80% quality setting usually come in at around 4 to 5 MB. I would expect 2100 px on the long edge at 80% would come in at around 2MB. I would not use higher than 80%/Q10 for any JPEG image. I have tested this thoroughly and I could not even measure a significant difference between that and a 100% JPEG file. Actually the difference between the 100% JPEG and the TIFF was of the same order as the difference between the 80% and the TIFF. When testing the difference in an 8 bit file had variances of pixel values that were generally less than +-3 in any colour channel. The difference in file size between 80% and 100% is significant, the 80% file will be between 40% and 60% smaller! I have seen situations where 100% JPEG files have actually been bigger than uncompressed TIFFs!

Alan

Some pretty good information in the thread. Here's some more information/opinion:

- You know the size of the prints you want - 5 inches by 7 inches.
- Generally, for "small" prints on quality photo paper, you're aiming for about 300 pixels per printed inch*
- Simple math gets you to your final pixel dimensions: 1500x2100 pixels.

* (sometimes called ppi, sometimes called dpi, it's an oft-debated topic but for this purpose the semantic quibbles are not relevant)

- Pixel count is only loosely related to file size. Don't get megaPIXELS and megaBYTES confused; they're not the same thing.
- 1500x2100 = 3.15 million pixels, or 3.2MP.
- But, due to different file formats and compression types, the file size (in megabytes) can vary widely even if the pixel count stays the same.
- You CAN'T judge "image quality" solely on file size in megabytes, except for at the extreme lower end, where image compression is so intense that detail is lost and unwanted artifacts are introduced.

- Generally, a jpeg will be plenty fine for sending to print.
- Even a little bit of compression is okay. There's almost never any visible difference between, say, 100% quality and 85% quality - and those differences go away once it's printed.
- Here's a good link showing jpeg compression in Lightroom: http://regex.info …room-goodies/jpeg-quality

- So, in Lightroom:
--- Make sure your images are all cropped to 5x7
--- In the Export dialog, make the following settings:
----- Resize, Long Edge to 2100 (it'll figure out 1500 automatically since it's a 5x7 crop)
----- 300dpi (though this doesn't really matter any more, now that you've used it for your pixel-dimension math)
----- Jpeg quality to 85%
----- Sharpening, set to Low or Standard, Matte or Glossy paper (whatever you're ordering)


And enjoy your prints.

[Important note] One more thing: If you haven't ever calibrated your monitor, it's a great time to do so. If your monitor is too bright (most people's are) then what looks good on the screen will be too dark on paper. If you can't/won't calibrate your monitor, at least turn your brightness down to half and check all the images again.

Thanks again people, love those fast answers, great great help!