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Crop affects dpi in Photoshop CS5?


YES. Should be no reason not too. What format are you saving/sending it in?
 
Z1000 said:
In .jpeg, cmyk profile ;)
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Just for your information, jpeg is not very good for printing. It is a lossy format and each time it is saved it loses quality. I suggest a tiff or a PDF.
 
Z1000 said:
Is it too late now to convert jpeg to tiff? Because don't have final .psd file.
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No, just open the jpeg in Photoshop . The File/Save as and choose tiff or Photoshop PDF. Is this going to a commercial print house?

Also, in the future, when your working on a file and have need to open and close it several times, you should save as a Photoshop PSD file. As I said, your quality loss occurs as the image is opened and closed and is compressed multiple times.
 
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Should I use these options?

8Yjv66m.jpg


I'm sorry I don't understand you with this ''commercial print house''? I'm printing it at local printing store for personal use, I've used to send im jpegs earlier.

Opening and closing jpeg without save also compresses file? If I just want to see it in photoshop, and not edit it also doing this? I didn't know that :/
 
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LZW compression is OK. Makes for a smaller file and does no harm. Interleaved is fine. For Byte Order that's old technology.either one is OK

Edit: I'm sorry I don't understand you with this ''commercial print house''? I'm printing it at local printing store for personal use, I've used to send im jpegs earlier.

Opening and closing jpeg without save also compresses file? If I just want to see it in photoshop, and not edit it also doing this? I didn't know that :/

I am not saying that the jpegs won't work. It's just not best practice.
You can't close it without saving it..that's where your loss of data comes in.

The only other thing that I question is the CMYK color space. Most people today work in RGB and send to the printer in RGB unless he specifies otherwise. Modern printers convert the color data presented to them to CMYK that the printer (machine) uses. But that opens up another subject of color management etc. I can only assume you have done the proper things as you created your poster.
 
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I saved it without compression it's 266mb large:lol: jpeg was 67mb large. I have one more question. I don't see some details in acdsee as i see it in photoshop, am I going to see these vertical stripes on paper or it is going to be like on right picture?

CGvKPiV.jpg


I don't know if you can see difference but image on the right side is better quality, that's how I see it in ACDsee and I wonder if it is going to look like that on paper.

When I was doing first poster they told me that I have to send them file in cmyk profile so I continued to do it that way.
 
My bad, it's because acdsee differently see's cmyk profile, there are stripes when i'm viewing it with windows picture manager.
 
What you see in Photoshop is what will print or at least it's supposed to. If the printer wants CMYK then that's what your giving him. I suppose the proof will be in the final print. OTE=Z1000;1533697440]My bad, it's because acdsee differently see's cmyk profile, there are stripes when i'm viewing it with windows picture manager.[/QUOTE]
 
Your welcome :wave: Have a good trip to the printer!:beer:
Z1000 said:
Ok, thanks good people, I'll report results when I see it finally on paper.

Cheers smile_drunk_cheer.gif
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I have to ask one more thing. Maybe it's because my laptop monitor. Do you see vertical stripes on the left side of this picture or it's just me?

CGvKPiV.jpg


When I'm looking it from the top there are no stripes, but from down there are some stripes on it. I don't know how to explain exactly, but here is pic

Wide_Viewing_Angle.jpg

Guy on left see's stripes, guy on right don't :)
 
Sorry, but simply opening and closing a JPG file in any program that I know about does not decrease its quality one iota. Ever. Period.. That is an erroneous statement that you see repeated over and over again on the Internet. Opening and intentionally re-saving it does degrade it. Most of the time, the effect is small. At low jpg quality settings, the loss of quality in each generation can be obvious. If you don't believe this do a test yourself.

Tom
 
Tom Mann said:
I agree with Larry (ALB) and Mr. Tom that the change in dpi when cropping is *extremely* odd. In decades of working in PS, I've never seen this happen, so I suspect you inadvertently changed the dpi in some other way and only noticed it when you were dealing with the cropping issue.

However, there are easy ways (independent of the dpi number reported by PS) to check if you lost significant amounts of information during the process you described. If so, you would need to go back and correctly crop your image.

For example, I assume that for safety you have been saving different versions of your PSD file as you worked, so you probably have a version just b4 you began the crop related operations, and then another version after all of the manipulations you did.

If so, then simiply convert each version to a JPG (using the same quality factor), and compare the two file sizes. If you cropped away only a few percent of the image, then these two file sizes should be within 10% of each other. If they are not, you've lost more information than you think, and you need to go back, and using a conventional, single step, approach crop your image. If you still can't do this, tell us what happened and we will try to figure out why and help you get through this.

Good luck,

Tom M

PS - The reason I'm suggesting such a seemingly odd way (ie, comparing file sizes) to compare the two versions of your image is that I'm worried that your odd cropping process indeed created a file with the correct pixel dimensions, but has lost more information than just a little bit around the edges. The method I described is a quick and dirty way to tell this that doesn't rely on any dpi numbers.
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. @OP - if you answer the *EXACT* question I posed in my earlier post (quoted immediately above), you will learn a lot.

Tom M
 
Tom,
I may have stated that incorrectly, but it was my intent to get the OP to get out of the habit of saving everything as a jpeg, which is perfectly fine in some cases, some not. It goes back to my early training with graphics programs (25 years ago) I was taught by experts that jpgs are a "lossy" format. This was not just something I picked up off the internet. Now, we can debate just how "lossy" they really are until the cows come home, but it IS a known fact that with compression they do degrade. Now, if you have a format that you know is going to lose data and possibly some of your quality, why use it if you have alternatives that are known not to? This is especially true if your going to print. So, why not be safe rather than sorry and save in native Photoshop during your working process and in the final product, send it out as a PSD if your print house can accept it that way. Otherwise, save it as a Tiff or a PDF. PDF's are a favorite of mine as they are truly a Portable Document Format as Adobe intended them to be. Almost everyone can open them, they do not degrade quality and they retain vector information if used.
Possibly the attached links will be helpful to some readers (not you of course, as I know you know this stuff backwards, forwards and upside down)
http://graphicssoft.about.com/od/graphicformats/f/summary.htm
http://graphicssoft.about.com/od/formatsjpeg/a/jpegmythsfacts.htm
Hopefully this information is not erroneous in your opinion
Best Regards
Larry

Tom Mann said:
Sorry, but simply opening and closing a JPG file in any program that I know about does not decrease its quality one iota. Ever. Period.. That is an erroneous statement that you see repeated over and over again on the Internet. Opening and intentionally re-saving it does degrade it. Most of the time, the effect is small. At low jpg quality settings, the loss of quality in each generation can be obvious. If you don't believe this do a test yourself.

Tom
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