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01-05-2009, 06:42 PM   #1
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B & W Conversions - What's Going On?

Here are three B & W conversions of shots from a recent outing at the local college. They all - to one degree or another - contain artifacts around the edges of the lighter parts of the subject (something like the pinwheels I see prior to a migraine). These aren't present (in TIF prints or JPEGS on my screen) prior to transfering these pictures - thru PhotoBucket. Anybody know what this is about?

Thanks,

Jer








01-05-2009, 07:00 PM   #2
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Moved to correct forum.

Jer, I can't see anything on my screen, can you do a crop to just show the areas affected?
01-05-2009, 07:03 PM   #3
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I'm not seeing what you're seeing Jer. But the usual issue is site compression. It's actually better to make the images smaller before downloading to a host site. Make it something around 1000 x 1000 and then download it to the site. That has always worked for me.
01-05-2009, 08:09 PM   #4
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PhotoBucket recompresses files if they exceed certain size and/or size. The main reason why I have stopped using PhotoBucket. Check dimensions and size of your original and the resulting on Photobucket - they will be different!

In other words, no matter how much time you spend fine-tuning the size, JPEG compression level and sharpening for given size, PhotoBucket will affect that.

I don't know if this limitation applies only to free accounts or to paying users as well, but I have only had a free account.

01-05-2009, 08:27 PM   #5
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Thanks guys.

I always shrink my stuff to 650 on the "long" side before uploading to PhotoBucket (free) - I've not seen what is on my monitor for these shots before. Looks fine before I upload - guess something's happening that doesn't agree with my monitor.

Spooky. If you guys can't see it, maybe I'm "seeing things".

Jer
01-05-2009, 10:06 PM   #6
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I see compression artifacts. Did you check the size? Do "Save As..." from PhotoBucket and compare size in bytes ("Size", NOT "Size on disk" -- right click -> Properties...) between the original and uploaded one. What is the result?
01-06-2009, 05:18 PM   #7
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QuoteOriginally posted by Ivan Glisin Quote
I see compression artifacts. Did you check the size? Do "Save As..." from PhotoBucket and compare size in bytes ("Size", NOT "Size on disk" -- right click -> Properties...) between the original and uploaded one. What is the result?
Ivan, I did as you suggested. The image before loading to PhotoBucket is 112 KB; the version I saved from PhotoBucket is only 3.0 KB! Is that possible?

Jer

01-06-2009, 07:07 PM   #8
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QuoteOriginally posted by Sailor Quote
Ivan, I did as you suggested. The image before loading to PhotoBucket is 112 KB; the version I saved from PhotoBucket is only 3.0 KB! Is that possible?
Unlikely, that must have been a thumbnail. Here are the size of all three photographs linked from PhotoBucket in your original post, in the same order as in the post:

Pic 1: 89.16 KB (91301 bytes)
Pic 2: 102.74 KB (105201 bytes)
Pic 3: 63.99 KB (65527 bytes)

Check local copies and compare.
01-07-2009, 04:43 PM   #9
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Thanks for going to the trouble to do this, Ivan.

#1 and #2 are, respectively, 94.3 and 112.4 KB. Unfortunately, I accidentally dumped #3 last night.

What's that tell me?

Jer
01-07-2009, 08:47 PM   #10
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QuoteOriginally posted by Sailor Quote
Thanks for going to the trouble to do this, Ivan.

#1 and #2 are, respectively, 94.3 and 112.4 KB. Unfortunately, I accidentally dumped #3 last night.

What's that tell me?

Jer
Exactly what I have mentioned in the first post: upon uploading, PhotoBucket recompresses JPEGs to lower quality, apparently to save space. The problem is that for small JPEGs compression quality of, say, 80 and 60 may result in very similar size that depends on the actual content, and in some cases 60 may may be even slightly larger, but with lower quality.

Bottom line: if you want full control stay away from PhotoBucket.
01-08-2009, 05:10 PM   #11
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QuoteOriginally posted by Ivan Glisin Quote
Exactly what I have mentioned in the first post: upon uploading, PhotoBucket recompresses JPEGs to lower quality, apparently to save space. The problem is that for small JPEGs compression quality of, say, 80 and 60 may result in very similar size that depends on the actual content, and in some cases 60 may may be even slightly larger, but with lower quality.

Bottom line: if you want full control stay away from PhotoBucket.
Ivan, you're a scholar and a gentleman - thanks for all the help. I guess I'll have to move "upmarket" from PhotoBucket.

Is that an MX your eye is peering into? I've got a couple of them - I haven't used them for many years, but I loved them when I did.

Jer
01-09-2009, 03:26 AM   #12
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Interesting observation there Jer.

Those artifacts are most pronounced to me on image two, along the upper margin of the first arch. (so no, you are not seeing things!)

Thats's enough for me to not recommend photobucket that is for sure!
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