Sony A900- REal world experiences

[hobbsr]

i All,

I happen to have the opportunity to test the Sony A900 camera with the CZ24-70 lens, I have read with interest many discussions regarding higher iso performance of this camera. Can any of the professionals out there that are using this system give me some insights to the real world performance of this system at iso 800, 1600 and 3200? I have tested in a very limited way and of course find the level and nature of the noise (Chroma) to be much more (higher) noticeable than my current D3's. I am not so much trying to compare with the D3 but rather to find out from others that have real experience if the performance can be use at these levels when you see the final image or output? From my own tests I seem to be able with some further NR to get an ok image, that is to pixel peep at, the images above 800 do seem to lose more sharpness than I am use. I am shooting RAW and have all NR turned off in the camera, I am trying the files in the latest C1 and Aperture, I am also trying Nik Define 2.0 and Noiseware for the NR.

Thanks for any advice and experience that you can share as I am very interested to see if the A900 can support my wedding work. Of course why would I change from D3's to A900 mainly the option of the CZ lens 16-35, 24-70, 85 1.4 and 135 1.8, I also think that the Sony flash as a great design.

Regards

 

[Dave_Anderson]

The a900 doesn't like underexposure. Search for "UniWB", a technique that can show you histograms that represent the true "RAW" exposure. Usually for RAW PP you will want to expose +0.7EV to +1EV over what the usual "Normal WB" histogram indicates is acceptable, actual compensation to be determined by experimentation. Basically set exposure using UniWB, then switch to appropriate WB and shoot.

By most accounts the noise becomes a non-issue when printing, though I have not printed any high ISO images myself.

 

[Bill_Green]

The noise performance of the A900 is anywhere between atrocious and not quite up to Canikon level, depending on the image. To answer your question directly, 800 I don't give a second thought to using, 1600 is noisy but that can be mitigated in C1, 3200 I try to avoid if I can, or convert to B&W, which has a lovely look.

Today I shot a lady with dark hair in a black dress giving a presentation in a poorly (tungsten) lit room. I know there will be a lot of noise, however I quickly realized that with the built-in image stabilization I could comfortably shoot at 800 (hand held at 1/20). C1 does a very effective job taking out the chroma noise. I tend not to be be too aggressive with luma noise because it doesn't really show in a print.

FWIW, I use ISO 320 as my base ISO for image quality reasons and generally leave NR off in C1. At 800 and below, noise of any kind really isn't an issue in print, though you do see it on screen.

For C1, do a search on the forum for a profile called "skin-test."
My standard settings are as follows (each image is tweaked from here):
Film curve: linear
WB: 5700/0 (may need a little magenta as the profile is a bit green/yellow, but still better than the C1 profile)
Exposure: +0.4
Contrast: +5
Brightness: +35
Saturation: +20
Levels: Auto, but set the mid point manually
Curve: Flat for people, Contrast for everything else, a little mid boost when needed
Sharpening: 180/1.3/1.0
Local Contrast: 20
Noise reduction: depends. 20/3 or 0/0 is pretty standard. Dark areas show more noise.
Moire: 0/8 (minimum settings, can't turn off)

I think that is it. I actually have had more of an issue with clipped highlights than with shadow noise. I tend to shoot it like film, expose for your most important detail and place it where you want it to read, rather than expose to the right. To be honest, I don't understand how to use the meter or the histogram on this camera. I have the meter at +1.0 and all other settings at 0, seems to work. The histogram is generated from the jpeg and there are a bunch of settings that affect how it reads jpeg exposure.

There is a lot of discussion online about using UniWB to enhance dynamic range and I need to look into that. The single biggest issue I have found with the camera is the lack of a decent profile. With the exception of the profile that comes with Raw Photo Processor, they all suck. Maybe the camera is just hard to profile.