PDA

View Full Version : Eos7D noise



Baiazid
12-09-2010, 2:33pm
Hello,

I have this camera for one month and I am a beginner.

I noticed some noise and dunno if this is normal: ISO100, no filters except UV

Why so much noise?

ZOOM 1:1

I added a screen capture to see.
58465

pmack
12-09-2010, 3:02pm
what lens were they taken with?

Baiazid
12-09-2010, 3:05pm
what lens were they taken with?

Tamron 17-50mm f/2.8 XR Di II VC LD Aspherical IF SP AF (Tested)

http://www.slrgear.com/reviews/showproduct.php/product/1297/cat/23

ZedEx
12-09-2010, 10:10pm
are you taking images in JPEG or RAW? I suggest RAW and do your own sharpening, generally most in-camera JPEG sharpening is pretty hard and could define noise more. Either that or turn the sharpening down in the picture styles menu.
Also, are your images underexposed to begin with, or are they absolutely straight from the camera? If you are lightening these AT ALL via the Canon supplied software, photoshop or otherwise, you will bring out hidden noise in darken regions of your images.

ZedEx
12-09-2010, 10:18pm
also, the other thing to consider is that '100%' from an 18 million pixel image is quite a tight crop. Ie: are you ever actually going to do an enlargement anywhere near 40x60inch or however big 100% works out to be in print? Probably hardly ever, and even then that amount of grain is perfectly fine for such a massive print.
A lot of comparisons of noise are done at 100% on say a 12mp camera vs an 18mp camera, and really it's not an accurate comparison of a 'real life' noise situation

Baiazid
12-09-2010, 10:28pm
Hello ZedEx,

I am shooting only RAW and I do the post processing in AL3.2

I shot a little bit under exposed (is not like I prefer, this is the result though). Still learning...

Now I have this: 7d + Tamron 17-50mm f/2.8 XR Di II VC LD Aspherical IF SP AF + UV filter

and sometimes Pol Filter.

Still a n00b

ZedEx
13-09-2010, 8:05am
polariser/lens choice won't lead to excess noise. That is well and truthfully an in camera issue. IMO it's probably from taking them underexposed a tad. Take a picture of something neutral in tone and colour, defous the lens and let the camera expose the image as it would, with no Ev adjustments in camera or in post process. Then chuck that image up and we'll have a look. Shouldn't be seeing any noise at 100% at 100iso in this trial

Baiazid
13-09-2010, 9:23am
I will bring camera to work tomorrow and shoot something in daylight.

I noticed yesterday similar noise on my Pentax K-7 shots.

I shoot in M mode 90% of my time, so no EV adjustments

I will make some tests:

1. first pic in AUTO
2. then I will play with different Shutter-speed settings


If I look at this websites:

http://www.dpreview.com/reviews/canoneos7d/page15.asp
http://img697.imageshack.us/f/5390.jpg/

They have some noise too in 7D ISO 100 RAW

Baiazid
14-09-2010, 6:47pm
I did the some tests today and here is what I noticed for ISO100:

1. Adobe Lightroom 3.2 has luminance default to 0 (i import and convert to dng)

2. AL3.2 luminance ~=30-40 is equivalent with DPP3.8.1 import

3. Side by side AL3.2 luminance 30-40 and DPP3.8.1 are similar in noise

4. On my screen #1 Dell2209WA, in full screen size, pictures look AMAZING. But zoom1:1 you can see the noise if is not corrected (for AL3.2).

58582

58583

58584

58585

58586