Resolution setting for cropping photos

Dogdots

I'm cropping some photos to print and I'm not sure on what to set the resolution to in CS3. Any suggestions for 4x6's and 8x10's? Would any size be the same resolution?

Andy

Leave it blank.

Art Scott

Dogdots wrote:

I'm cropping some photos to print and I'm not sure on what to set the resolution to in CS3. Any suggestions for 4x6's and 8x10's? Would any size be the same resolution?

Are you actually cropping or resizing under the image tab......here is how I go about it....first of all I go to image and down to image size....there I see the size and pixel dimensions of the photo....and the dpi (native is normally 72dpi) ....I am wanting to get as close to 8x10 as possible and also keep as many pixels as possible, so.....I clik contrain proportions ONLY and every thing else is blank.....I change my dpi to 300 and this brings my photo to very near 8x10 in size.....if I need to crop I do so now.......if it is way smaller on any 1 side then I take it into Genuine Fractals (at 300dpi) and uprez to 8x10 or 16x20 or 32 x 40....to get my aspect ratio correct for 8x10 and 4x5 prints.....but I also have it ready for large enlargements atthe same time.

Dogdots

Oh no....I have two totally different answers :cry

Not to impose, but may I ask why it can be either left blank or changes made before cropping? Just want to learn

Travis

Dogdots wrote:

Oh no....I have two totally different answers :cry

Not to impose, but may I ask why it can be either left blank or changes made before cropping? Just want to learn

As with everything in Photoshop, there are multiple paths to get to the same place. Photoshop User magazine had a good article this month on using the crop tool. Elaborating on Andy's statement - by leaving the resolution blank, the image gets resized but does not get resampled when cropped. If you specify a resolution,the image gets resized and resampled, possibly leading to image degradation. If you are downsizing the image, this isn't too much of a concern but if you are expanding the original size, then it can have a negative impact on image quality. As Art pointed out, there are tools out there that can help.

Art Scott

Dogdots wrote:

Oh no....I have two totally different answers :cry

Not to impose, but may I ask why it can be either left blank or changes made before cropping? Just want to learn

Are working in the same workflow......You see I was always afraid to use the crop tool on a native 72dpi photo that is 42x30 inches and have crop tools set ofr 8x10....so I go into the image tab and start my work.....I am just paranoid as far as this goes.....also by changing my dpi to 300 it shows me if my native photo will do an 8x10 and how much crop is needed and with my 6mp Konica Minolta files they do not come out above 8x10....so I have to enter into GF to get the aspect ratio correct before any printing is done......my cams pixels dimensions are 3008 x 2000@72dpi {41.778Inches X 27.778 inches} & {@300dpi = 10.027 inches X 6.667 inches} and yes I can do it as Andy suggest but that gives an [email]8x10@250dpi.....my[/email] way gives me an 8x10@300dpi and makes me feel better even if that 50pixels really do not make a difference and I do not know as I have never done a printing test on my files.

When resizing under the image tab (image -> image size).....never never ever have the resample box tic'ed.....I have never gotten a decent photoshop resample...that is why I purchased Genuine Fractals all those years ago.....it also downsizes wonderful when I want to make avatars and such.....either direction is just one step

digismile

Leaving it blank is like using a pair of scissors and simply throwing away the excess. This is what I would use all the time.

When you fill in a number, it crops and resizes at the same time. It could be resizing up or down depending on your crop. You generally need 200 - 300 pixels per linear inch of print. The suggested number for many inkjet printers is 240.

So what does this mean? Let's say your original image is 3000 x 2000 pixels and you want to crop for a 4" x 6 " photo and you specifiy 300 for the resolution. In this example, you crop significantly, selecting an area that is 1200 x 800 of the original size. By specifying 300 dpi, the image would then be upsized to 1800 x 1200 (6" x 300 dpi and 4" c 300 dpi). This probably wouldn't be a very good thing. You are taking a small area and increasing it by 50%.

But maybe you aren't so agressive in your crop. Let's say that you crop an area that is 2400 x 1600 and specify 300 dpi. In this case, the crop takes the original down to 2400 x 1600 and the the 300 dpi further downsizes it to 1800 x 1200. Follow?

The thing is, some photos can stand more resizing than others. I generally crop and then resize after. The reason is, I will resize differently depending on whether I am increasing (Bicubic Smoother) or descreasing (Bicubic Sharper) in size.

So, I agree with Andy's original suggestion of leave it blank ...:D

Dogdots

I understand now how this works.

Bummer I don't get Photoshop User Magazine...sounds like that was an informative article.

Thank you everyone for your help

Art Scott

digismile wrote:

Leaving it blank is like using a pair of scissors and simply throwing away the excess. This is what I would use all the time.

When you fill in a number, it crops and resizes at the same time. It could be resizing up or down depending on your crop. You generally need 200 - 300 pixels per linear inch of print. The suggested number for many inkjet printers is 240.

So what does this mean? Let's say your original image is 3000 x 2000 pixels and you want to crop for a 4" x 6 " photo and you specifiy 300 for the resolution. In this example, you crop significantly, selecting an area that is 1200 x 800 of the original size. By specifying 300 dpi, the image would then be upsized to 1800 x 1200 (6" x 300 dpi and 4" c 300 dpi). This probably wouldn't be a very good thing. You are taking a small area and increasing it by 50%.

But maybe you aren't so agressive in your crop. Let's say that you crop an area that is 2400 x 1600 and specify 300 dpi. In this case, the crop takes the original down to 2400 x 1600 and the the 300 dpi further downsizes it to 1800 x 1200. Follow?

The thing is, some photos can stand more resizing than others. I generally crop and then resize after. The reason is, I will resize differently depending on whether I am increasing (Bicubic Smoother) or descreasing (Bicubic Sharper) in size.

So, I agree with Andy's original suggestion of leave it blank ...:D

This is only true if you are re-sampling the image....if you do as I suggest you retain all of the pixels until you crop....or gain pixels in the case of my 6mp KM7D....if you are shooting 8+mp then the image sizing will be greater than 8x10 as with my KMA2 prosumer P/S........but I guess it comes down to what one is willing to be happy with and I have so many cleints that do not understand viewing distance that I just found it simplier to keep every enlargement at 8x10 resolution (300dpi) no matter if it is a 16x20 or 60x80 inch print, not to mention how impressive it is to see one hanging that you can be nose to photo to and not see the grain (pixels).


I forgot to add in my previous posts....if you want a size that is not in the 8x10 aspect ratio....then all one needs to do while in the image size tab is to put in 4 x 6 and it automatically changes the dpi to reflect this size and as long as the only tic'ed box is constrain proportion is is not doing any resampling.......so it is still native pixel sizes....this is the very top of the image size box............I always use the image size area to confirm what actual print sizes I can get and if I need to go the GF route or not......It cuts down on what cleints can order but it is also the most popular sizes for the last 30 -50 years for portraits and such.


Now maybe cs3 and 4 have greatly improved the re-sampling engine of PS but in anything from PS4 thru PS CS2 it just down right sux no matter the method used for uprezing......that is what lead to my purchase of GF and has made me a believer.....also I should mention I shoot atthe lowest ISO that the camera can shoot at....my KM A2 is always set for ISO64 and my 7D's are set at 100......I hardly ever shoot above that....of course if I get a DSLR that is noiseless at ISO3200 then I may change my stratigies .....a little.

jdryan3

Art Scott wrote:

....and the dpi (native is normally 72dpi) ....

I'm not sure I understand the 'native' portion of the comment. My 'native' is 240 out of ACR, but even that is adjustable. The jpegs out of my old 300D were 180 dpi. I've only seen 72 dpi when I change it to that resolution for exporting to the web. Is this a function of your camera settings?