DPChallenge: A Digital Photography Contest You are not logged in. (log in or register
 

DPChallenge Forums >> Tips, Tricks, and Q&A >> confusion saving images
Pages:  
Showing posts 1 - 19 of 19, (reverse)
AuthorThread
09/09/2013 02:52:28 PM · #1
I'm perplexed by an image which when saved at low res looks sharper than when I save it at high res. Any ideas?
09/09/2013 03:31:17 PM · #2
I may depend on the viewing magnification -- 100% is the best, then 50%, 25%, 12.5%, etc. If you use "fit to window" or any other percentage you typically lose detail because of the math involved in fitting your image pixels onto the matrix of the display pixels.

When I scale down for entries, I usually use a 25% reduction (makes it smaller than 800 pixels) for the same reason.

ETA: I expect ' . substr('//www.dpchallenge.com/images/user_icon/21.gif', strrpos('//www.dpchallenge.com/images/user_icon/21.gif', '/') + 1) . ' kirbic should be along soon with a more specific explanation ... ;-)

Message edited by author 2013-09-09 15:33:58.
09/09/2013 03:43:16 PM · #3
No, this is for printing purposes. I'm not saving it, knowingly, with any restrictions. But when I blow it up on my screen, there is a significant loss of detail. The image looks grainy at this higher resolution than it does on the compressed version.
09/09/2013 03:52:30 PM · #4
Are you enlarging the larger version from the camera's original dimensions?
09/09/2013 04:00:31 PM · #5
No, not originally. I've tried smaller, larger, but they all look grainy for some reason.
09/09/2013 07:13:33 PM · #6
One possibility that occurs to me is that there is a limitation set on the output file size, and the software is compressing the higher resolution version heavily to meet this requirement. Not that any of us ever use a specific file size limitation ;-)
09/09/2013 08:24:17 PM · #7
Yup, never done that either.
09/09/2013 08:36:18 PM · #8
Are you converting from 16-bit to 8-bit? using compression?

If your original has multiple (adjustment) layers you might try merging them down one at a timne instead of flattening all layers at once -- I've gotten some strange effects at the flattening stage before.
09/10/2013 12:31:52 AM · #9
Hmmmm, THAT is an interesting angle. I'll look into this.
09/10/2013 04:59:20 PM · #10
Which program are you saving the file in? If its PS and you do a SFW the max dpi is 72 and may cause some resolution loss at larger viewing sizes, if you do a "save as" it will save the file in what ever properties you have set for the image. Just a thought!
09/10/2013 05:18:14 PM · #11
Nope, not savung foe web. I set it at 300 dpi and saved as a jpg.

I haven't been able to figure out if the 8/16 bit switch caused the issye, but ir loiks like I might have ti reedit the whole thing....
09/10/2013 05:22:02 PM · #12
Originally posted by tanguera:

Nope, not saving foe web. I set it at 300 dpi and saved as a jpg.

That's possibly your problem. You're often trimming pixels when you do that, depending on the dimensions you dial in. There's no need for it unless you're trying to do some specific with a print. Do NOT adjust the DPI when saving your file otherwise.

Message edited by author 2013-09-10 17:22:10.
09/10/2013 10:00:45 PM · #13
Originally posted by Bear_Music:

Originally posted by tanguera:

Nope, not saving foe web. I set it at 300 dpi and saved as a jpg.

That's possibly your problem. You're often trimming pixels when you do that, depending on the dimensions you dial in.

I don't like the term "trimming" here because it sounds too much like cropping, when I'm sure you mean resampling.

If you set both the physical dimensions and DPI at the same time in the Image Size dialog you will be resampling, and will almost inevitably lose detail.
09/10/2013 10:14:46 PM · #14
Holy crap! So how do I set it to print a large size (say 24 x 36) without losing sharpness?????
09/10/2013 10:52:24 PM · #15
Originally posted by tanguera:

Holy crap! So how do I set it to print a large size (say 24 x 36) without losing sharpness?????

Short answer: if you're working with a good lab, let them do the upsampling. YOU just process the image and save it as a PSD or TIFF file for them. They have VERY good products for upsampling and they do it all the time.

If you're getting a large-format printer to do your own large prints, then it's time to study. There's a wealth of material out there.

But a good custom lab prefers that you leave the upsampling to them.
09/10/2013 11:01:38 PM · #16
in PS under image>image size the box will tell you the largest size the image will print at based on the dpi you create. If you uncheck the resample box and change the dpi it will automatically change the image size accordingly and you shouldnt loose any details in the final image. Even though it says certain sizes at certain dpi's you shouldnt have too many issues with a 24x36 if your image has atleast one edge at 4000px and the other at 3000px when your at 240dpi

I have a couple of screen shots below that describe it. There is a lot of technical jargon that goes along with it but as Bear mentioned your lab should be able to upsample the image if it falls below those guidelines. I printed a 24x36 that had less pixels than what I mentioned above and it showed no loss of detail.

' . substr('//images.dpchallenge.com/images_portfolio/65000-69999/68503/120/Copyrighted_Image_Reuse_Prohibited_1082625.jpg', strrpos('//images.dpchallenge.com/images_portfolio/65000-69999/68503/120/Copyrighted_Image_Reuse_Prohibited_1082625.jpg', '/') + 1) . '

' . substr('//images.dpchallenge.com/images_portfolio/65000-69999/68503/120/Copyrighted_Image_Reuse_Prohibited_1082624.jpg', strrpos('//images.dpchallenge.com/images_portfolio/65000-69999/68503/120/Copyrighted_Image_Reuse_Prohibited_1082624.jpg', '/') + 1) . '

' . substr('//images.dpchallenge.com/images_portfolio/65000-69999/68503/120/Copyrighted_Image_Reuse_Prohibited_1082622.jpg', strrpos('//images.dpchallenge.com/images_portfolio/65000-69999/68503/120/Copyrighted_Image_Reuse_Prohibited_1082622.jpg', '/') + 1) . '
09/10/2013 11:10:45 PM · #17
All this time.... and I've been submitting jpgs...

So, once I've saved the PS file with the resampling (which resulted in the loss of detail), can it be undone? Can I return the image to its original detail? Or do I have to start from scratch?

And why is it that some images (all saved the same way) had NO loss of detail, while others show significant loss?
09/11/2013 12:54:26 AM · #18
Originally posted by tanguera:

And why is it that some images (all saved the same way) had NO loss of detail, while others show significant loss?

It's entirely dependent on the kind of detail in the image and how the compression algorithm handles it. You shouldn't be printing from JPG; you're a pro :-)
09/11/2013 04:14:12 AM · #19
Originally posted by Bear_Music:

you're a pro :-)


Apparently, a rather ignorant one!!!
Pages:  
Current Server Time: 07/21/2019 07:14:50 AM

Please log in or register to post to the forums.


Home - Challenges - Community - League - Photos - Cameras - Lenses - Learn - Prints! - Help - Terms of Use - Privacy - Top ^
DPChallenge, and website content and design, Copyright © 2001-2019 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Proudly hosted by Sargasso Networks. Current Server Time: 07/21/2019 07:14:50 AM EDT.