Originally posted by JohnSetzler :
2- using standard jpg mode instead of fine mode may also affect it more...
What else could play a role in this? I'm going to try to take a few sample photos at lower resolutions in standard and fine mode to see what difference it makes....
Standard, fine and super fine modes in your camera are simply controlling the amount fo JPG compression your camera applies to the image before it saves it to the CF card (or memory stick). That's the exact same process as when you save a file out of photoshop and you make a decision about how much JPG compression to apply.
Something that might be affecting some people is the number of times the file has been loaded, edited in some way and then saved again. Each time you do that you amplify any JPG artifacts in your picture.
Here's an example:
First of all - this is the picture I'm using to demonstrate the point. It's one of many photos I *should* have submitted to "My Corner of the World" rather than the one I actually did.
Next I took that small crop and saved it. I then closed the file, re-opened it, made a very small edit (I just placed a 1 pixel green dot in the bottom left corner each time) and the re-saved it (using Photoshop's standard JPG compression which is level 7). I did that about 5 times. This is the result.
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09/26/2002 09:03:07 AM · #28 |
I played around with this some more last night. Gordon showed me some very easy ways to test and produce these problems. Based on things I learned from Gordon, I have made a few assumptions and drawn a few conclusions.
1 - I'm not completely confident that the resolution of the camera plays the largest role in this problem. In my sample images that I posted links above, I resized those from 2560x1920 to 640x480 BEFORE I applied the compression. So, in essence, I started the compression on a .3mp image.
2 - Different photos behave differently when compression artifacts are involved. The colors, or lack thereof, play a role in how fast artifacts will start appearing.
3 - Most software applications have a 'default' setting for applying jpeg compression. This setting is NOT usually at a MINIMUM compression level. So, if you save your photo once, open it again, save it again, etc, you are compounding the compression each time you do this. If this is the case, it would be best to open your original photo and save it in the TIFF format. Working with the TIFF file while making edits to the photo would eliminate any unwanted compression. After all edits are complete and the final image is ready, then convert it back to a JPG file for submission...
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09/26/2002 11:04:24 AM · #29 |
| Is there any enthusiasm out there for a one week challenge for photographs without computer manipulation of any kind - straight from the camera as shot. There must be other people without the computer expertise to successfully compete in this technological wonderland. Any thoughts? |
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09/26/2002 11:05:55 AM · #30 |
I think it would be a great idea but impossible to validate...
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