Iliah Borg ISO-boosting in post tested with A900

Here are two FULL size (click through) jpegs processed with the suggestion of Iliah Borg on dpreview.

For those that don't know, his suggestion was to meter with ISO 3200 and then kick it down to ISO160 (cameras "actual" best ISO setting according to Iliah) and bring up the shadows in post. I used ACR 5.2 and attempted to make the images as identical as possible w/r/t exposure.

NOTE: Camera was set to +.7EV when metering (force of habit now).

NOTE2: Yes, I'm on a diet

NO sharpening, NO noise reduction, in-camera high-ISO noise control OFF. 50mm f/1.4 @ f/5, 1/50 sec.

Weirdly, the ISO 160 jpeg is 2 MB (!) smaller than the ISO3200 jpeg. Is that all noise?!?!?!?

ISO 160 has a definite edge in the dark-areas.

ISO 160




ISO 3200



Edited by lattiboy - 09 December 2008 at 10:22

Thanks for you comparison shots. I have done something similar yesterday going down from ISO3200 to ISO400 and strangely my results were not good and I was not happy. Might have to re-shoot once more. I thought the ISO3200 was more pleasing re. noise than the underexposed ISO400 shot.
Stef.

I'm pretty good at pixel peeping, but I don't see a significant difference between these two shots. Also, I'm not sure what you mean by 'FULL size (click through)' images. I assume these have been scaled down from the entire frame, and there are no 100% crops. But, if the file size of the first one is smaller as you said, that does indicate lower noise.

EDIT: Actually, it could also indicate reduced detail; but I can't tell from these images.

Edited by sybersitizen - 09 December 2008 at 19:35

I would just like to say that i'm glad to find that iliah has started influencing a-mounters. There is a LOT one can learn from him (and his daughter for that matter) about (digital) cameras ;) and only the fact that he has and use a900 is a great thing for the system IMHO.

@ lattiboy: Thanks for sharing this! I immediately did some tests myself (with the A700, ISO 200 vs ISO 3200) and was very surprised to get similar results. However, I could only get the pictures to look similar when using Raw Photo Processor; when doing a +4EV adjustment in LightRoom however, things look horribly bad (oversaturated, super noisy, way too much contrast, etc.).

So what settings did you use to do make this enormous push look so "normal"?

Thanks a million,

Florian

To Florian


that´s because ACR may not the best converter for A900 files. still would be interesting how lattiboy got his results.

diglloyd has also reviewed the A900 and compared the sony converter with Raw Developer. It´s like night and day. there is a huge difference between the sample files.

he did also a comparison with the canon eos 1D mkIII. Sony comes out really good.

Hey guys, I'm at work now, but I got the results from ISO160 by increasing overall exposure AND brightness. It actually comes out fine if you control it well.

I'll post line-by-line settings when I get home tonight.

PS Sony needs to deal with this whole underexposure problem soon! It would be easy if it ALWAYS underexposed by -1EV, but sometimes it hits just fine and then I've blown out perfectly reasonable highlights.