Reading mode: Light Dark

Green noise...

Go to last post
J

JohnClif

Senior Member
Messages
1,564
Reaction score
235
Location
Bellevue, US
No,

It can be bad when underexposing. I sent a couple snapshots to Mike G of one of our dogs taken at twilight (ISO 400, on camera flash). One in which I was a little farther away was underexposed by about a stop, and showed significant noise. The other was exposed properly, and there was virtually no noise.

It's a steep slope. Thankfully the B/W conversion are much better. And the SD14 is way better than the SD10 in this regard, with the exception that if you underexpose in bright sunlight---you'll see more noise in the 14 than the 10.

--
Jim
 
Exposure is critical. Last weekend I had the opportunity to shoot f/2.8 and ISO 800 in a mixture of tungsten and natural light. If most of the histogram was slightly to the left of center I had slight yellow blotching here and there. When exposure was proper or even slightly to the right of the center of the histogram I had no problem. I even accidentally overexposed an ISO 1600 shot by center metering on a dark cow in a barn (about 1 stop darker than 18% gray). I was able to 'pull back' the highlights and that one stop of over exposure left me with an incredibly clean shot with NO noise at all. And that's at ISO 1600!
JLK said:
No,

It can be bad when underexposing. I sent a couple snapshots to Mike G
of one of our dogs taken at twilight (ISO 400, on camera flash). One
in which I was a little farther away was underexposed by about a
stop, and showed significant noise. The other was exposed properly,
and there was virtually no noise.

It's a steep slope. Thankfully the B/W conversion are much better.
And the SD14 is way better than the SD10 in this regard, with the
exception that if you underexpose in bright sunlight---you'll see
more noise in the 14 than the 10.

--
Jim
Click to expand...
--

Only pass judgement upon the prints you see. Your 100% crop is a shadow on the wall of a cave.
 
It's not posted. It's slightly blurry--about a 30th or 60th of a sec. But I'll try to post it in a day or two.
--

Only pass judgement upon the prints you see. Your 100% crop is a shadow on the wall of a cave.
 
Here is a link to the ISO 1600 sample.

http://www.pbase.com/chromelight/image/85511952

Keep in mind it was overexposed by about 1.5 stops. If I had exposed properly the shutter would have been faster, less light would have hit the sensor, and there might have been more noise.
george c wilson jr said:
Hi Chromelight,

Would you mind linking us to that shot? I am interested in seeing how
it did.

geo.
Click to expand...
--

Only pass judgement upon the prints you see. Your 100% crop is a shadow on the wall of a cave.
 
what are you using to process the X3f's? The pattern of the noise in your photos looks like that you get from an image processor not optimised for SD14 X3F's
 
Uhhh, it's called SPP 2.2 for the Mac. That's the SD14 version. The shot is at ISO 1600 under a mixture of tungsten and natural light.
alisD said:
what are you using to process the X3f's? The pattern of the noise in
your photos looks like that you get from an image processor not
optimised for SD14 X3F's
Click to expand...
--

Only pass judgement upon the prints you see. Your 100% crop is a shadow on the wall of a cave.
 
Hey everybody,

I just picked up an SD14 and am having a very hard time with tungsten light. Anything that has yellow or red...read flesh tones comes out totally yellow with all other colors being spot on. There is no way to correct for this..I have tried everything! I am sending the camera to Sigma due to the flash giving an error code every time I use it and locking up the camera. The cam is brand new but I need Sigma to calibrate my 30mm f1.4 lens with it. Maybe I will get a new camera. I have no problems with flourescent lighting...just tungsten!
--
Gleaming the Cube as always,
Jim
 
Yeah I get them a great deal on underexposed shots.... SPP3 doesn't seem to show them but when I process the raw files with dcraw just about any underexposed shot at a high ISO will do this.
 
i was asking john :)

i use SP2.2 on mac too. I find if I use a custom white balance, don't under expose and don't use Fill Light then my ISO1600 come out OK. not great but OK.

know your enemy :)
 
...which from what I've read has some problems.

I've tried using SPP 2.1 (1892) for the PC and while I can't zoom in on SD14 files in 2.1, I can use the magnifier tool, and it shows significant green noise in darker areas.

This is sometimes noticeable on ISO 100 shots, but becomes more apparent at ISO 200 and above on darker areas.

I never saw this with my SD10. I think it's due to the smaller photosites being more susceptible to noise when there's not a lot of light (less signal means the same amount of noise raises the SNR).

Any ideas? My idea would be for Sigma to release an updated SPP 3.01 that fixes the 16-bit-actually-being-8-bit issue, and also come up with a way of filtering out green noise. Or, maybe I need to buy Noise Ninja (sigh).
--
'Do you think a man can change his destiny?'
'I think a man does what he can until his destiny is revealed.'
 
gbainbridge said:
JohnClif said:
Any ideas?
Click to expand...
Have you tried Kent Dooley's photoshop action?

It's accessible on my website:
http://bainb.dyndns.org/Foveon/Removing_Foveon_%27Pattern%27_Noise.html
The blue sky noise reduction works well with this type of noise.

You can access my explanation for the noise at
http://bainb.dyndns.org/Foveon/Foveon%20noise.html where you will
also find my script for PSP.

--
Thanks,
Gary.
Click to expand...
Gary,

I'm still using Photoshop Elements 4.0. It is my limited understanding that (albeit in a somewhat awkward way) Photoshop Elements may be able to utilize certain Photoshop Actions, subject to some limitations on complexity. Do you know if these reductions can be used with PE?

Kind regards,
--
Ed_S
http://www.pbase.com/ecsquires
 
Ok.. I have downloaded the Sigma Pattern Noise Reduction.atn.txt file and have to admit I have absolutly no idea how to integrate it with Photoshop CS3 Actions running
on my Mac Pro. Any possibility of directions for the clueless?
 
I thought I posted an answer to that but it seems to have disappeared.

I don't know much about Macs, but on a PC, you open the Actions window, click on he little symbol at top-right to get to the menu, then select Load Actions.

I don't know about Elements 5, but I believe it can support actions provided they don't make use of functions that elements doesn't have.

--
Thanks,
Gary.
 
Hi Cyberguy

Try to put on a blue filter 80A or 80B when shooting tungsten. You loose one or two steps, but it will strengthen the blue channel. Problem is that tungsten has very little bue.
cyberguy said:
Hey everybody,
I just picked up an SD14 and am having a very hard time with tungsten
light. Anything that has yellow or red...read flesh tones comes out
totally yellow with all other colors being spot on. There is no way
to correct for this..I have tried everything! I am sending the
camera to Sigma due to the flash giving an error code every time I
use it and locking up the camera. The cam is brand new but I need
Sigma to calibrate my 30mm f1.4 lens with it. Maybe I will get a new
camera. I have no problems with flourescent lighting...just
tungsten!
--
Gleaming the Cube as always,
Jim
Click to expand...
--
Kind regards
Øyvind Strøm
http://www.pbase.com/norwegianviking/sd14
http://www.norwegianviking.smugmug.com
http://www.pbase.com/norwegianviking
 
You must log in or register to reply here.

Keyboard shortcuts

f
Forum
m
My threads
Mobile site
About
Editorial content
Cameras & Lenses
Community
All content, design, and layout are Copyright © 1998–2025 Digital Photography Review All Rights Reserved.
Reproduction in whole or part in any form or medium without specific written permission is prohibited.
When you use DPReview links to buy products, the site may earn a commission.
©GPS Media - Guides, Products, Services.
Back
Top