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08/04/2009 12:35:09 PM · #1 |
I was wondering if there was a tutorial, or if anyone had some good advice about preparing images for uploading for challenges. I'll say from the beginning that I haven't been able to calibrate my monitor yet, but have generally been happy with prints I've made, so I consider my monitor setup to at least be "close". My problem is when I go to upload to this site, images seem over-saturated and not as sharp as they look beforehand. I'm not sure if this is from the downsizing- I do apply a bit of USM after the downsize. But saturation / color wouldn't be effected by resizing would it??
Any tips would be greatly appreciated...I'll throw up a link for an image as example after the july free study is over...
Erik |
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08/04/2009 01:00:31 PM · #2 |
You can try this tutorial on this site:
//www.dpchallenge.com/tutorial.php?TUTORIAL_ID=26
Message edited by GeneralE - Made link clickable. |
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08/04/2009 01:16:53 PM · #3 |
What editing software are you using to prepare your images?
I can tell you that the thing I tend to nail people on in challenges is excessive jpeg compression. I'll usually deduct a point or two from my vote if I see the effect of compression, which are easily avoided. If I see compression induced artifacts or visible softness, I check the image properties for a small file size, which indicated too much compression was used. Compression robs detail Always use the least amount you can get away with and still slip in under the challenge limit. |
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08/05/2009 07:13:35 AM · #4 |
thanks for the feedback- I'll look through that tutorial before next time.
I use LR2 for some global adjustments, PS CS4 to stitch together, finetune etc.
I did the compression to size for the challenge by saving the long side of the image @ 700px, then decreasing the jpeg quality such that the file size requirement was met. I guess it might be better to decrease the size a bit more and keep the quality up? Again... I'll throw a link up here in a few days once the voting is done (so I don't steal some sympathy votes for 70th) and maybe some suggestions will come of that as well.
thanks,
Erik |
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08/05/2009 07:28:55 AM · #5 |
Originally posted by ErikTurner:
I guess it might be better to decrease the size a bit more and keep the quality up? |
Unless you are only trimming a few pixels off the edge, you will probably get low voted for noticeably small sized images. Most images will survive a moderate amount of compression. It's those sub 100 kilobyte shots that tend to show noticeable loss of quality. A better option may be to put a modest border on the image if you need to shave off a few k. Of course there are border-haters as well. Can't please everyone. You can also leave out the exif data from your entry to shave of a couple of k. |
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08/05/2009 07:42:43 AM · #6 |
Photoshop's "save for web" option allows you to choose a target file size, and compresses the image to meet that size, expressing the result as a %. For basic editi8ng maximum file size is 150kb on a 640-pixel maximum image, for advanced it's 200kb on 720 pixels. Save for web strips the exif data for you, saving a little space.
The amount of compression needed will depend greatly on the amount of detail and color information required. B/W images tend to save to a very high percentage, as do any shots with, for example, large expanses of blue sky. Wide-angle shots with lots of intricate detail tend to require a lot of compression. In all cases, the more yous harpen the more compression will be needed to reach the target filesize, and in all cases the closer your image is to being square (640x640, 720x720) the more pixels it contains and the more compression it will require to reach the target filesize.
In advanced editing, you can use selective sharpening (on faces, for example, but not on backgrounds) to keep the compression at a higher level. Noise reduction will always reduce required compression. If you have a noisy image, you can try running noise reduction on, say, the blue channel if you have a lot of sky, and sometimes reduce compression noticeably that way without affecting image detail much at all.
There's a lot of approaches to maximizing quality within the fixed filesize limits...
R.
Message edited by GeneralE - Corrected typo specifying file dimensions. |
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