Help, please! - DPChallenge Forums

Canon EF-S 18-200mm f/3.5-5.6 IS

09/06/2005 09:36:56 PM · #1

I don't know what the heck is going on - I'm not doing anything differently then normal, but my images are coming out very weird. I don't know if it's a camera issue, or my editing, but I swear I'm not doing anything different. My images are coming out extremely...blotchy - I don't even know how to describe it...but below are two 100% zooms on an image. The first one was converted through the RAW utility in Photoshop 8 as an 8bit JPG. the second, which is only marginally better, was converted as a 16bit tif and then converted to 8bit JPG to compress for web. What is causing this?

Stephanie

CEJ

Canon EOS-40D

09/06/2005 09:39:30 PM · #2

Not sure what is causing it. Have you cleaned your sensor recently? The first looks like residue from a wet clean that wasn't removed. The second looks like noise.

Was the camera exposed to temp. extremes where condensation could form?
Did this happen suddenly? Like one pic it is fine and the next it is this?
Is your card ok? Have you tried shooting with a different card/lens? (eliminate as many things as possible - if same with new card, not that/if same with new lens, not that either)

Message edited by author 2005-09-06 21:41:49.

Canon EF-S 18-200mm f/3.5-5.6 IS

09/06/2005 09:41:21 PM · #3

Originally posted by Alienyst:

Not sure what is causing it. Have you cleaned your sensor recently? The first looks like residue from a wet clean that wasn't removed. The second looks like noise.

I don't think it's the sensor - I've seen it on other pictures by other people on the list - it's as if it's overcompressed, but It's happening on files that I don't edit at all. So I'm wondering if maybe my card is damaged, or maybe needs to be re-formatted.

CEJ

Canon EOS-40D

09/06/2005 09:43:58 PM · #4

Don't know what list you are talking about, but 'I don't think it's the sensor' does not eliminate it as suspect. Try reformatting the card, using a different card, using a different lens. That will narrow it down pretty fast. If you are not doing anything different than 'normal' then what you are saying is it is the camera.

09/06/2005 09:46:18 PM · #5

sorry - I meant to say on this site, not on the list.

09/06/2005 10:00:45 PM · #6

does anybody else have some suggestions, please? This concerns my livlihood.

Thanks.

savannahjames

Canon EOS-300D Rebel

09/06/2005 10:09:12 PM · #7

It does look overcompressed - does it occur when you shoot with the camera set on JPEG where no conversion is necessary?

~Savannah

Message edited by author 2005-09-06 22:10:19.

09/06/2005 10:14:13 PM · #8

Can you put a total untouched straight from the cam shot up somewhere for us to look at? I've seen this happen when a resize for web has gone wrong, usually jpgs though.

Andy

ED: Are these resized or 100% crop?

ED: ED: Never mind you stated 100% in OP...oops I just turned 46 today and have lost my mind... :)

Message edited by author 2005-09-06 22:16:22.

09/06/2005 10:20:17 PM · #9

Originally posted by savannahjames:

It does look overcompressed - does it occur when you shoot with the camera set on JPEG where no conversion is necessary?

~Savannah

I try not to shoot in JPG, as the RAW settings are much more to my liking, but I guess I should try.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

09/06/2005 10:24:16 PM · #10

Still looking for ya, but here is a bit about Dithering is what it looks like to me...

savannahjames

Canon EOS-300D Rebel

09/06/2005 10:31:11 PM · #11

Originally posted by atsxus:

Originally posted by savannahjames:
It does look overcompressed - does it occur when you shoot with the camera set on JPEG where no conversion is necessary?

~Savannah

I try not to shoot in JPG, as the RAW settings are much more to my liking, but I guess I should try.

I'm not familiar with RAW myself, but the reason I asked is that if it doesn't show up when you shoot as JPEG, then I would assume it must be something going wrong in the conversion process. If it does show up then, I would think something has gone wrong either with your card or the camera.

~Savannah

GeneralE

Canon PowerShot S3 IS

09/06/2005 10:31:22 PM · #12

Sometimes it's not the photo at all, but the monitor settings getting changed. See if you've somehow got the monitor changed to 16-bit (thousands of colors) or 8-bit (256 colors) instead of 24-bit (millions of colors) -- some games will change the monitor setting for you.

burtct

Canon EF 24-105mm f/4.0L IS

09/06/2005 10:34:39 PM · #13

I noticed that with processing canon raw pics through photoshop raw processor - while you can adjust some things nicely, but it does come out very grainy. I got around it by using the Canon software (Zoombrowser if Iremember it correctly) to convert to tif and then post process it in photoshop.

I have just got a new EOS 350D which comes with a new Canon photo processing software which allows you to tweak far more things than the old software did (very similar to the Photoshop RAW input, but without the absolute color temperature settings). This seems far superior to the Zoombrowser version, but it does not handle CRW files - only CR2 and JPG. I am not sure of what raw format your camera uses.

Mail me if you want more info - I am not at home right now but will be able to tell you more about it this evening if you are interested.

Chris

Canon RF 24-70mm f/2.8 L IS

09/06/2005 10:37:04 PM · #14

Originally posted by burtct:

Canon Digital Photo Professional v1.6.1 I believe and yes it is sweet to work with.

ED: My bad (again) DPP does do RAW, I think DPP comes with the 350 but not the 300.

Message edited by author 2005-09-06 22:38:41.

kirbic

Canon EOS R5

09/06/2005 10:38:38 PM · #15

It looks to me like posterization in the first crop, and just JPEG compression in the second crop. The JPEG compression artifacts will start to show in areas that are very uniform in color. those ares are also where posterization will occur.
Theposterization usually happens where curves have been adjusted pretty severely, and the colors are "compresed" into just a few discrete levels. The JPEG artifacts are from trying to make a file too small for the information it contains. Couple questions:
1.) What are the pixel dimension of the original?
2.) What is the compressed file size, in kB?
3.) Can you post a reduced size version of the entire image?

09/06/2005 10:40:18 PM · #16

Originally posted by GeneralE:

I don't play games on my computer. I use it to work on my photography and my websites - however if it were the monitor, wouldn't I notice a difference in everyones photos and not just my own?

09/06/2005 10:47:49 PM · #17

Originally posted by atsxus:

Originally posted by GeneralE:
Sometimes it's not the photo at all, but the monitor settings getting changed. See if you've somehow got the monitor changed to 16-bit (thousands of colors) or 8-bit (256 colors) instead of 24-bit (millions of colors) -- some games will change the monitor setting for you.

I don't play games on my computer. I use it to work on my photography and my websites - however if it were the monitor, wouldn't I notice a difference in everyones photos and not just my own?

Besides that we are seeing it in your photos...and not our own.

09/06/2005 10:49:49 PM · #18

Originally posted by kirbic:

Couple questions:
1.) What are the pixel dimension of the original?
2.) What is the compressed file size, in kB?
3.) Can you post a reduced size version of the entire image?

Here is the original file as it came out of the RAW wizard with minimal adjustments.
Full sized image at 3072x2048 at 240 pixels

kyebosh

Canon EOS-20D

Canon EF 80-200mm f/2.8L

09/06/2005 10:51:29 PM · #19

the first picture is only 7.5kb and is pretty big... it's probably compression.

09/06/2005 10:52:53 PM · #20

If you are using Windows open an out of camera photo using MS Picture and Fax Viewer and see it if looks the same there.

Right Click the Untouched Photo > Open with > Windows Picture and Fax viewer

If it looks ok there than Photoshop is doing some weirdness. It's Almost like you are using and Indexed Color workspace instead of sRGB or Adobe RGB.