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01/14/2006 09:35:30 PM · #1 |
I had an odd thing happen... as I was preparing my photo in Photoshop CS, I resized it to the 640 size and tried to save the JPEG. I had to lower the quality all the way down to a 3 âlowâ out of 12 âmaxâ before the file would fit in the 150 kb limit.
Why is it so large?
I think it might be because of the complexity of the background... Would that increase jpeg file size? If so... Would re-shooting with a narrower DOF (thus blurring the background) enable me to shrink the file and up the quality setting? |
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01/14/2006 09:36:54 PM · #2 |
| I think the more black or darker your colors, the larger the jpg, no matter the image size... |
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01/14/2006 09:41:44 PM · #3 |
I don't think that's right. Images that have lots of information all over the image, by that I mean a LOT of detail are going to larger in size than an image that has little detail (i.e. image almost all black and all white).
ShotMD: did you try saving your image using "Save for Web" with Photoshop after resizing your image to 640 px. The save for web image only saves what's important an gets rid of a lot of the other info that just takes up file space. |
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01/14/2006 09:44:43 PM · #4 |
Originally posted by ShotMD:
I think it might be because of the complexity of the background... Would that increase jpeg file size? |
High frequency "signals" will definitely increase the size of a jpeg file. To see this happen, oversharpen a file with color noise. The sharpened file will be much larger. |
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01/14/2006 09:46:09 PM · #5 |
You're right.
"Jpeg is a discrete algorithm, and for a given quality setting different input images may give widely differing file sizes. An image with lots of texture and fine detail will produce a large Jpeg file, while one consisting only of blue sky will be very small. Chosing an appropriate Jpeg quality setting is a subjective decision, with no hard rules. I personally use IJG quality settings of 75 to 50 depending on the subject."
//www.photo.net/learn/jpeg/ |
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01/14/2006 09:53:47 PM · #6 |
Originally posted by ShotMD:
I had an odd thing happen... as I was preparing my photo in Photoshop CS, I resized it to the 640 size and tried to save the JPEG. I had to lower the quality all the way down to a 3 âlowâ out of 12 âmaxâ before the file would fit in the 150 kb limit.
Why is it so large?
I think it might be because of the complexity of the background... Would that increase jpeg file size? If so... Would re-shooting with a narrower DOF (thus blurring the background) enable me to shrink the file and up the quality setting? |
Go to Save For Web and look for the little arrow on the right hand side of the dialog box next to Preset. Click it and go to Optimize to File Size and type in 150 in the Desired File Size box. You should not have to adjust the JPG quality the way you did. Doing so the way you did will create an image that is unpresentable for viewing on the web.
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01/14/2006 10:08:19 PM · #7 |
Originally posted by nsbca7:
Go to Save For Web and look for the little arrow on the right hand side of the dialog box next to Preset. |
Wow -- never noticed the little arrow before! Is there a way to save a preset that will automatically size it to close to 150k? I tried making a "DPC" preset, but it would only reduce it based on the specific quality setting of the one I had saved (which will produce varying file size levels depending on the shot). It would be cool to make a preset based on the size.
Message edited by author 2006-01-14 22:10:14. |
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01/14/2006 10:19:42 PM · #8 |
Originally posted by alanfreed:
Originally posted by nsbca7:
Go to Save For Web and look for the little arrow on the right hand side of the dialog box next to Preset. |
Wow -- never noticed the little arrow before! Is there a way to save a preset that will automatically size it to close to 150k? I tried making a "DPC" preset, but it would only reduce it based on the specific quality setting of the one I had saved (which will produce varying file size levels depending on the shot). It would be cool to make a preset based on the size. |
Once you click it and click Optimize to file size, type in 150, next time you click optimize and it pops up, it stays at 150, just hit enter.
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01/14/2006 10:23:49 PM · #9 |
Originally posted by dpaull:
Once you click it and click Optimize to file size, type in 150, next time you click optimize and it pops up, it stays at 150, just hit enter. |
That'll do :) |
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01/14/2006 11:01:22 PM · #10 |
| Wow... thanks for all the feedback and help. I will change how I save from now on. I will still probably go back and reshoot tomorrow with a narrower DoF, anyway. Thanks. |
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01/14/2006 11:02:54 PM · #11 |
| Has anybody found that if a file is really close, say 147 to 149 KB, that DPC will think it's too big anyway when you upload it? |
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01/14/2006 11:05:11 PM · #12 |
Originally posted by DrAchoo:
Has anybody found that if a file is really close, say 147 to 149 KB, that DPC will think it's too big anyway when you upload it? |
Never had that problem on this site. I often have that problem (250 kb) over at OMP.
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01/14/2006 11:06:02 PM · #13 |
Yeah I have had that problem on DPC - 148kb and larger it seems to think that's too big. lol
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