images: A900 vs A99 RAW high ISO comparison

Started Nov 9, 2012 | Discussions
barri
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images: A900 vs A99 RAW high ISO comparison
Nov 9, 2012

I had my A99 now for 3 days, and I must say that I like it a lot. Mostly for its EVF, faster AF, lighter weight, and video capability, when compared to my A900. Especially the EVF I prefer so much more over an OVF. It's great to be able to tweak your exposure before you actually take the picture.

But also in terms of IQ the A99 is a step up. This is most apparent at high ISO. See below two comparisons of 100% crops. Shot at ISO 6400 and with the same lens.

A900 is on the left, A99 on the right.

All processed in LR 4.2. I'd say that the A99 looks much better.

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remylebeau
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to barri, Nov 9, 2012

Nice comparison. See this is what bothers me about those that say it's not worth the upgrade because both sensors are 24mp. There's so much more to a sensors performance than just megapixels.

After shooting with the a99 this week it's so clear noise performance is much improved, and the dynamic range is outstanding.

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barri
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to remylebeau, Nov 9, 2012

remylebeau wrote:

Nice comparison. See this is what bothers me about those that say it's not worth the upgrade because both sensors are 24mp. There's so much more to a sensors performance than just megapixels.

After shooting with the a99 this week it's so clear noise performance is much improved, and the dynamic range is outstanding.

I fully agree with you.

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OntarioJohn
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to barri, Nov 9, 2012

I agree big time.  What to do with that 77?

Lots of used Sony cameras will hit the market I guess.

Retired forensic photographer.
London, Ontario, Canada.

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taamberg
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to barri, Nov 9, 2012

OK, I am NOT a troll - in fact, I own both an A900 and a brand-spanking new A99.  However (well, actually "therefore") I want to make any comparison of these two fine cameras as fair as possible.

The truth is that there IS that semi-translucent mirror that robs light in the A99, affecting exposure.  I'm assuming that both the A99 and A900 in your comparison were set to the same aperture and shutter speed, as the A99 came out roughly a third stop darker than the A900.

Therefore, I went and "evened the odds", by boosting the exposure in photoshop over on the A99  side of your jpg so that it matches the exposure and colors of the A900.  The results are below.

This still shows a victory for the A99, but yes, noise is now more visible than in the original shot. I'd say that overall the reduction of noise is such that you get a gain of twice the resolution on the A99 when shooting at 6400.

That's good, AND you get all the advantages of the SLT - for me, most notably, focus peaking and the ability to spot-check 100% focus while looking into the viewfinder.

(6400 is the ISO is here, right?  I can't get back to your original post while typing this.  And also, why is all my text centered?!?  Oh, the joy of the new forum....)

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philbot
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to taamberg, Nov 9, 2012

taamberg wrote:

OK, I am NOT a troll - in fact, I own both an A900 and a brand-spanking new A99. However (well, actually "therefore") I want to make any comparison of these two fine cameras as fair as possible.

The truth is that there IS that semi-translucent mirror that robs light in the A99, affecting exposure. I'm assuming that both the A99 and A900 in your comparison were set to the same aperture and shutter speed, as the A99 came out roughly a third stop darker than the A900

The exposure difference seen has nothing to do with SLT..

Internally, the camera's simulate ISO by applying gains to the sensor signal prior to RAW, any SLT light loss can be taken care of by that mechanism.

It is normal that some camera's have low and some cameras have high ISO gains, leading to what looks to be darker/lighter exposures for the same camera exposure settings..

The A77 confirms this as it produces brighter exposures for the same camera settings then most of it's competition, this is why DPReview/Imaging-Resource who match output exposure levels always give it faster shutter speeds for the same aperture then most camera's, which is exactly the opposite of the A900/A99 scenario.

I agree that ideally you should match output exposure, and as you have done, do it in PP.. doing it by giving the camera's different amount of light (as DPReview and IR do amongst others) is not the right way to do it for ISO comparison.

Don't forget that RAW converters also have some responsibilty in this, the algorithms differ per camera and it's up to each RAW converter to set the overall default exposure from the RAW Data.. so you can get variance there..

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Alan_S
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to OntarioJohn, Nov 9, 2012

OntarioJohn wrote:

I agree big time. What to do with that 77?

Lots of used Sony cameras will hit the market I guess.

Retired forensic photographer.
London, Ontario, Canada.

My thoughts exactly, John. That's the only "problem" I've encountered with the a99 so far... thought I'd keep the a77 as my telephoto body, use the a99 for portraits & landscape, but am finding the a77 remains capped in the bag while I swap lenses on the a99. Same thing happened when I bought the a77 a year ago (to team up with the a850); didn't take long for my a850 to hit eBay.

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Nordstjernen
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to taamberg, Nov 9, 2012

taamberg wrote:

Therefore, I went and "evened the odds", by boosting the exposure in photoshop over on the A99 side of your jpg so that it matches the exposure and colors of the A900.

But you started with a medium or low quality jpg file, and this is for sure NOT a good start for comparing the two cameras. You should do this from raw.

Also, SLT is compensated for, so this should not affect light metering or exposure settings.

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taamberg
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to Nordstjernen, Nov 9, 2012

Nordstjernen wrote:

But you started with a medium or low quality jpg file, and this is for sure NOT a good start for comparing the two cameras. You should do this from raw.

Fair enough - absolutely true, but I didn't have access to this particular RAW, and I can't shoot my own A99 RAW yet, as Aperture (my paid-for flow tool of choice) hasn't been updated to handle it.

Also, SLT is compensated for, so this should not affect light metering or exposure settings.

There's where we disagree.  The A99 and A900, at least in this example, had a fairly large difference in perceived exposure.

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Nordstjernen
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to taamberg, Nov 9, 2012

taamberg wrote:

There's where we disagree. The A99 and A900, at least in this example, had a fairly large difference in perceived exposure.

There is nothing to agree or disagree about, since we do neither know the exposure settings nor the behaviour of the raw converter used.

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barri
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to Nordstjernen, Nov 9, 2012

Nordstjernen wrote:

There is nothing to agree or disagree about, since we do neither know the exposure settings nor the behaviour of the raw converter used.

these were shot with aperture priority at f8.0 and ISO 6400. Shot in RAW and converted at standard settings in LR 4.2.

Whichever way one sees it, IMO the A99 has substantially better DR and noise levels.

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GuyMcKie
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to barri, Nov 10, 2012

Standard settings are better for some sensors and bad for another. Each sensor has his own tonal curve, wb, contrast and saturation. And small adjustments have a big impact on the result.

I personally think that it is not possible to make conclusions on comparisons with standard settings. The Nikon D600 looks better in LR4 than the A99 with the standard settings. Adjust the exposure, contrast, wb and contrast to match the picture of the D600 and they look similar.

Adjusting the above sample of the A900 to match the same exposure, contrast, wb and saturation of the A99 sample and the comparison could be quite different.

We have the same problem with the comparison of raw convertors with their own standard settings. The final result is more the result of the experience of a user to tune the program for a specific sensor.

The sony IDC has by example the reputation to extract less detail and to create a more coarse and grainier noise pattern. The program is not user friendly and it is not easy to figure out how the settings for sharpness and noise reduction work. But it is possible to create a result that is very close in detail and noise as with LR4, but with better colors.

The first example here is a 6400 iso file of the A900, resampled to 6mp (50%) to save some bandwith and giving a better impression on how it prints. Converted with LR4.

A900 converted with lr4, saved as 6mp jpeg - 6400 iso

The second is a studio shot from ir with the A99 at 3200 iso, also resampled at 6mp. Converted with the Sony idc. Colors are better than with LR, look at the red swatches and green leaves. Despite the reputation of the idc the deep tones and shadows have smooth transitions and there is enough detail.

A99 converted with sony idc, saved as 6mp jpeg - 3200 iso

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mick232
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Re: images: A900 vs A99 RAW high ISO comparison
In reply to barri, Nov 10, 2012

barri wrote:

I had my A99 now for 3 days, and I must say that I like it a lot. Mostly for its EVF, faster AF, lighter weight, and video capability, when compared to my A900. Especially the EVF I prefer so much more over an OVF. It's great to be able to tweak your exposure before you actually take the picture.

But also in terms of IQ the A99 is a step up. This is most apparent at high ISO. See below two comparisons of 100% crops. Shot at ISO 6400 and with the same lens.

Everyone should know by now that the A99 is better at high ISO than the A900.

How about sharpness and CA comparisons at base ISO for a change? These are rarely done in forums and also in reviews, but comparing that would be exploring new territory instead of re-iterating what is already widely known.

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