A stupid question about CDs

ShepsMom · May 12, 2009

When you give a CD what resolution do you guy use?
I always give CD/DVD with prints that are only good for printing 4x6, i do re-size them to 800px on the longest side, and keep it at 300dpi. I was told by someone that instead of resizing picture, i should reduce resolution of the image. :scratch Wouldn't it make print quality kind of poor??

Cygnus Studios · May 13, 2009

ShepsMom wrote:

When you give a CD what resolution do you guy use?

It depends on the agreement in the contract.
Most of my clients are commercial and expect high resolution files and I charge accordingly.
If the client is using the files for their personal non commercial web pages, I will give 800 px long at 72 dpi.

Nikolai · May 13, 2009

I guess it's a "CD question" season

http://www.dgrin.com/showthread.php?t=130566

Tim Kamppinen · May 13, 2009

Sorry to get slightly off topic, but isn't it meaningless to specify dpi for a digital file without reference to print size? That is, say a file is 800x1000 pixels. If you print it as an 8x10, the print will have 800 pixels spread out over 8 inches and 1000 pixels spread out over 10 inches. Thus there are 100 "pixels per inch" or ppi (which I have read is a more accurate specification with dpi being an archaic, pre-digital term). But that's only the case if you print an 8x10. If you cropped the file so it was still 1000 pixels on the long dimension but in a 2:3 ratio, and printed as a 4x6, you would have 1000 pixels spread out over 6 inches. 1000/6 = 167 ppi.

So, if your photo is "800 pixels long at 300 dpi"... it's only 300 dpi at a certain print size. 800/x = 300... 800/300 = x...

x = 2.7

So your 800 pixel image is only "300 dpi" if you make a print 2.7 inches long. As a number attached to a digital file, with no print size specified, it's meaningless.

Back to the original question, then. By resizing the photo to 800 pixels long, you are reducing resolution. The files you give them will print a 4x6 at 800/6 = 133 ppi, an 8x10 at 80 ppi, and an 11x14 at 800/14 = 57 ppi.

You need to decide what an acceptable ppi is, decide what size prints you want your clients to be able to make while still having them turn out well, and size your disc images accordingly. So if you decide that 133 ppi is the limit of acceptable print quality, and you want your clients to only make 4x6 prints, then your current sizing works well. If you decide that 80 ppi still looks pretty good but you still only want your clients to make up to 4x6 prints, then you better downsize your images because at the current size they will be able to make 8x10s at that ppi. For what it's worth I've printed an 8x10 at 180 ppi and had it look great. You'll have to decide though what is acceptable. Keep in mind that you as a photographer probably have higher standards than your customers. Just because you think something won't look good when printed as an 8x10 doesn't mean that you customer won't print it out and hang it on their wall and think it's great.

Note that in PS if you crop something it generally has a ppi of 300 in the crop menu bar. I always delete this number before cropping. If you don't then photoshop actually resizes your image to make it 300 ppi at whatever crop you're doing. So if you crop at 8x10 and 300 ppi, but your image is only 800 pixels long, photoshop is going resize it to 3000 pixels long when you crop it. I always want to keep my photos at the native resolution unless I'm downsizing them, so I delete this.

EDIT: I should also point out that this tool can be used to size your images without resorting to algebra. Just set the crop at 4x6 and then enter the required ppi in the field. It will automatically downsample your image to the appropriate resolution. So if you have a 12mp file that's 4000 pixels long and set the crop tool to 4x6 at 100 ppi, it will automatically resize it to 600 pixels in length. You still have to decide what ppi is appropriate, however.

ShepsMom · May 13, 2009

Tim, thanks for your reply. I don't want them to print anything bigger than 4x6, it's stated and agreed on before any shoot takes place.
So far, it worked fine for me. I'm not sure if they can blow up 800x533px res. image to 8x10. So i think i'll stick with what i do currently. I actually haven't done any testing, because i always thought if Smug won't allow to "buy" anything bigger then 4x6, then i shall be safe!

Art Scott · May 14, 2009

What i have always done is to resize to 4x6 in ps (keeping the "constrain proportions" box ticked) and then I use the save for the web function....and make my resolution around 75-90 and this has given acceptable 4x6 for me......

Tim Kamppinen · May 14, 2009

ShepsMom wrote:

Tim, thanks for your reply. I don't want them to print anything bigger than 4x6, it's stated and agreed on before any shoot takes place.
So far, it worked fine for me. I'm not sure if they can blow up 800x533px res. image to 8x10. So i think i'll stick with what i do currently. I actually haven't done any testing, because i always thought if Smug won't allow to "buy" anything bigger then 4x6, then i shall be safe!

That's not a bad rule of thumb to go by. Still, if you wanted to check, you could just take one of the resized files to walmart and make an 8x10 print for $2 to see what it looks like.

Chris O · May 18, 2009

If a client buys a CD/DVD, I just give them half sized photos (my camera being 10mp) and charge enough to cover loss of print sales. I don't want my name on poor quality prints, so I would never limit the resolution to something that could only print a small size. Clients don't understand it, and will make lots of poor quality prints without knowing why.

Snowgirl · May 19, 2009

Chris O wrote:

If a client buys a CD/DVD, I just give them half sized photos (my camera being 10mp) and charge enough to cover loss of print sales. I don't want my name on poor quality prints, so I would never limit the resolution to something that could only print a small size. Clients don't understand it, and will make lots of poor quality prints without knowing why.

Very good point. I hate the thought of a client printing off a 72dpi file at 8 x 10 and then showing it to their friends saying X photographer took this - not exactly a ringing endorsement of my skills. I like the idea of bumping the price in order to compensate for lost print sales and then "let it go"

Might consider this model.

A stupid question about CDs

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