Really stupid question about cropping 8x10

[ajax_andy]

Sorry I know this is probably a stupid question, but take a picture from a DSLR, ok now you open it in Photoshop, set the crop tool to 8x10 inches... so far so good.

Now it crops the image to 8 x 10... big shock to me how much you actually lose doing this so I need to remember to leave a lot more space in future but thats by the by.

Anyway I decide it's not quite composed right now, so I crop again keeping the same 8 x 10 aspect ratio, but I dont drag the crop tool to the full size of the image and crop again.

Do this a few times and the image becomes quite small in size, but when I go to image size it states the document size is still 8 x 10 inches?!!

Soes this mean no matter how small I crop this using the 8 x 10 ratio it'll always just print it 8 x 10 inches? If so how will it display on a monitor? I compared it to another photo I'd just cropped once to 8 x 10 and left and they look different in size which is what I'd expect.... but both document sizes say 8 x 10 inches

Like I said its probably a really stupid question but I'm quite confussed by this!

[OsmosisStudios]

It'll always have the 8x10 ratio, but actual display size varies with screen size and zoom levels used in photoshop.

[RLucas]

I think that is correct? If you keep cropping it will keep the same ratios. You are basically "zooming" the more you crop. I think the program essentially interpolates to keep the ratio the same the more you crop. There will be a point where all resolution will be lost, and you will see nothing but the individual pixels.

[kcoppock]

You can size your image to a 80" x 100", if you want, but the quality will suffer depending on the pixel size. Say you have a 1600 x 2000 image you crop to 8" x 10". Your DPI is what becomes important, it tells you how many pixels are available to fit in one physical inch of space on your print. So your DPI in this case would be 200 (1600pixels/8inches or 2000px/10in). Then, you could always crop down to, say, a smaller 800 x 1000 pixel area of the image, and crop THAT to 8 x 10. Then, your DPI is reduced to 100 (800/8 or 1000/10), and the quality of your output will suffer.

[SwissJon]

Bear in mind that standard quality for websites is 75dpi (after which you're unlikely to notice the difference) and for photo quality prints is 300dpi, so the smallest you really want to crop your photos for an 8"x10" photo quality print is 3000x2400 if you intend printing them.

[ajax_andy]

Thanks everyone for the replies, I think I'm understanding this a little better now but still a little confussed... Is the following correct?

1) I can crop to 8 x 10 with no problems

2) I can then crop it again and as long as I keep the same aspect ratio it'll still always print 8 x 10. In fact I can crop it 10 times if I wanted to and it'll always print 8 x 10 - or in other words as long as the document size says 8 x 10 inches then it'll always print as 8 x 10 inches?

3) However with point 2 the dpi will start to suffer and so will the print quality... it will still print as an 8 x 10 print, but the image quality will be worse than just one crop of 8 x 10 from the original RAW file.

4) One thing if all the above is correct that I dont understand is that if I have two images loaded up in photoshop, one has been cropped once to 8 x 10, another has been cropped 3 times... both document sizes say 8 x 10 inches, but display as different sizes on screen (the more cropped version being the smaller image on screen).

[gturner]

8x10 is not a size when you crop, it is a ratio - it could be 4x5 - same thing

When you start printing - THEN it becomes a size order. You ask the lab to print the picture 8 x 10 and you will get a image 8 inches x 10 inches.

[ajax_andy]

Originally Posted by gturner

8x10 is not a size when you crop, it is a ratio - it could be 4x5 - same thing

When you start printing - THEN it becomes a size order. You ask the lab to print the picture 8 x 10 and you will get a image 8 inches x 10 inches.

So with regards how it is displayed on screen is this where pixel dimensions come in to play?

Basically I took some pics for a company and they need them for printing in the local paper & on their website & press releases.

I also am shooting a friends wedding next month and need to work out how to present these images to both parties, as the dimensions straight out of camera aren't in the correct dimensions I believe?

[SwissJon]

As GTurner said.. 8x10 is a ratio.

It doesn't matter howmany times you crop, it matters how many pixels you have on each edge.

IF you crop your file to 3000x2400 and then send it to the printer and ask for an 8x10 print, then you will have a very nice photo at 300dpi

If you crop it to 1500x1200 and send it to the printers and ask them to print it at 8x10 then their software will calculate the pixels in between the pixels and a substantial amount of of your picture will be "Guessed" by the interpolation software (

1500X1200=1920000 pixels.
3000x2400 = 7200000pixels
so there are 5280000 "guessed" pixels. (73%)

If you crop it even further, say to 750x600 pixels, the picture will be 1/4 the height and 1/4 the width of the original on the screen, however it will contain only 450000 pixels. That's just 6% the original number of pixels, 94% or them will have to be guessed.. You can imagine how much the photo will have degraded, no matter how good the interpolation algorithms are.

I think you start to get the idea.. Your zoom on the camera or move forward. The software solution is good, but not that good.

[ajax_andy]

Originally Posted by SwissJon

As GTurner said.. 8x10 is a ratio.

It doesn't matter howmany times you crop, it matters how many pixels you have on each edge.

IF you crop your file to 3000x2400 and then send it to the printer and ask for an 8x10 print, then you will have a very nice photo at 300dpi

If you crop it to 1500x1200 and send it to the printers and ask them to print it at 8x10 then their software will calculate the pixels in between the pixels and a substantial amount of of your picture will be "Guessed" by the interpolation software (

1500X1200=1920000 pixels.
3000x2400 = 7200000pixels
so there are 5280000 "guessed" pixels. (73%)

If you crop it even further, say to 750x600 pixels, the picture will be 1/4 the height and 1/4 the width of the original on the screen, however it will contain only 450000 pixels. That's just 6% the original number of pixels, 94% or them will have to be guessed.. You can imagine how much the photo will have degraded, no matter how good the interpolation algorithms are.

I think you start to get the idea.. Your zoom on the camera or move forward. The software solution is good, but not that good.

Thank you this is a great explanation

So with regards giving pictures to clients on disk for printing would you say 3000x2400 is the best size to go for?

I've looked in to this loads on forums and it seems everyone gives a different answer... Some say don't crop at all and us the size SOC but surely this would lead to uncontrolled cropping that might ruin a picture during printing?