I asked this elsewhere, but thought it was too much of a hijack.
My pictures from my 5MP camera are usually at 1.5MB or so. What’s a reasonable compression I can use for printing 4x6 pictures:
Physical size (pixels)
JPEG compression (1-11)
DPI (for batch processing)
I don’t want the bare minimum; I still want them to look fine. I just think it’s overkill to upload a bunch of 1.5MB files to Costco.
I use Photoshop Elements, what settings do you guys usually use?
Take pictures in the full 5 megapixel size (why else by a 5 MP camera). Most cameras have SuperFine, Fine, and Regular. I found shooting in Fine has no perceptable effect on image quality at the 4x6 or 8x10 size.
If JPG compression is more selectable the SF, F, and R for your camera (1-11 for example) choose anything above 7 and you’ll be OK. If space isn’t an issue you can choose 11 but you won’t be able to see any difference IMO.
DPI is for printing, just use the most pixels you have, the print driver will do the rest. Production printing is usually done at 300 dpi, most home printers are 225 or so. I just get the image as large as I can and let the printer take care of the rest. You really don’t have much control, nor would you want to. Once you select the print size, the DPI works out from image size.
Thanks Telemark!
What if I want the pictures to be less than full-size, less than 1.5MB, just to expedite uploading them to Costco for printing.
What’s the best size I can go to (eg 800x600 pixels) and Jpeg compression to get the file size smaller, yet not see a reduction in quality for a 4x6 photo?
General rule of thumb is 200-300 pixels per inch at the desired print size. So if you want to make 4x6 prints, you’d want to have at least 800x1200 pixels.
If you specify 4x6 and send more data, all you’re really doing is sending data that would do anything for your print, and will do something to your upload time.
Also, don’t forget to crop your image to 4x6 aspect ratio. Digital cameras aspect ratio is not 4x6, so some cropping will occur. If you do the cropping before uploading the file, you’ll be in control.
General rule of thumb is 200-300 pixels per inch at the desired print size. So if you want to make 4x6 prints, you’d want to have at least 800x1200 pixels.
If you specify 4x6 and send more data, all you’re really doing is sending data that would not do anything for your print, and will do something to your upload time.
Also, don’t forget to crop your image to 4x6 aspect ratio. Digital cameras aspect ratio is not 4x6, so some cropping will occur. If you do the cropping before uploading the file, you’ll be in control.
You may already know this, but be sure to check the aspect ratio of the images before you get them printed. I have the cheapo Coolpix 3200, and it doesn’t have an option to generate a 3:2 image. I’m so used to composing in a 35mm frame that I’ve had to re-train myself when shooting with my little digital camera–and it’s a real pain!
I think for printing purposes 300 dpi is about right. For a 4x6 that’s about 2 megapixels. If you shoot at 5 megapixels you can use Photoshop to reduce a copy to the desired size and still retain the original in case you want a bigger print at a later date. I don’t use Photoshop Elements, but in the full blown Photoshop go to Image->Image Size… Here you can set resolution to 300 dpi, check the Resample Image box and then change image size as desired.
Hey, GaryM, I wondered why my reply took so long to post: great minds think alike!
Thanks everyone, this is extremely helpful, I’ll give it a whirl.
In summary:
800x1200 (my camera has 3:2 ratio)
higher than 7 on the JPEG slider (at least medium, then).
300 DPI
IMHO 300dpi image size is really overkill. I only use it when a printer demands it. I suggest you do some tests starting at 180 DPI and see if there is any significant difference in quality. I don’t think you’ll find much if you are examining at normal distances.
I did some experimenting using Photoshop Elements:
Original pic (taken at 5MP 3:2) 1.68MB 2656x1904 pixels
Then I tried 3 options via Batch Processing:
1200x800 300dpi JPEG High Quality 183KB
1200x800 600dpi JPEG High Quality 183KB
1200x800 300dpi JPEG Max Quality 751KB
There isn’t a size difference with the DPI, just with High vs Max Quality.
Each picture looks identical for all intents and purposes, so I think I’ve found my setting, reducing the size by 90%
Picture in question:
http://www.dulcemichaelanya.com/anyaNE9.htm
Be cautious because reducint JPG quality isn’t alway consistent and may show compression artifacts on one photo while not showing it on another. You still have what I think is more resolution than is neccessary so you may try lower resolution while keeping JPG quality high.