Rishi Sanyal

Rishi Sanyal

DPReview Administrator
Lives in United States Seattle, WA, United States
Works as a Deputy / Technical Editor
Has a website at www.rishi.photography
Joined on Feb 25, 2014
About me:

Although I'm a scientist by training, having recently completed my Ph.D in biophysics, photography has always been a huge passion of mine. It's been an incredible opportunity to meld these two interests together here at DPReview!

Comments

Total: 4454, showing: 1 – 20
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In reply to:

beatboxa: He's got a great attitude & accomplishments, but there were a few areas that I think were missing in this interview: specifically, reliability and image quality.

He seems to equate things like 'corner sharpness' with 'better', but there are plenty of IQ aspects where the Arts fall short for certain applications. Portraits is a great example: when contrast, bokeh, tones, etc. matter. And the Sigma Arts generally don't do well in these areas.

Ironically, the Sigma "Arts" are some of the most technical and least character lenses out there. They should rename them to the Sigma "Sciences". :)

"Portraits is a great example: when contrast, bokeh, tones, etc. matter. And the Sigma Arts generally don't do well in these areas."

Evidence?

Actual MTF10 (contrast) data suggest Sigma Art lenses excel in the area of contrast.

'bokeh, tones' - no evidence to suggest there are any issues here. In fact, the 24 and 35 and 85 Art lenses have some of the most pleasing bokeh I've seen. [No onion rings](https://www.dpreview.com/sample-galleries/1444131463/sigma-85mm-f1-4-dg-hsm-art-sample-gallery/5815702684) and [buttery Gaussian](https://www.dpreview.com/files/p/articles/7705642292/DSC_1667-Edit-2.jpeg) if you ask me. Even shooting [wide angle](https://www.dpreview.com/files/p/articles/7705642292/DSC_0629-Edit.jpeg).

@notpc: Thank you.

Link | Posted on Feb 27, 2017 at 18:25 UTC
In reply to:

jlabate: I've always thought one of the appeals of medium format was 16-bit raw files but this Fuji sensor only has 14-bit. Anyone have thoughts on that?

Basically if full-well capacity (in electrons) divided by read noise > 16,384, then, yes, you'd benefit from a higher than 14-bit ADC.

I'm not sure it's easy to measure input referred read noise from actual Raw files, though, as it's impossible to tease out the noise added by the ADC (if any). I would've thought anyway. But I may be misunderstanding this. Been meaning to ask this in PST to get the input of Jim Kasson and Jack Hogan and Bill Claff.

For example, I believe the lower-than-expected DR of the a7S at base ISO is due to quantization error from a 14-bit ADC, as its pixels are too big. 155k electron full-well capacity with low read noise can't be quantized properly with a 14-bit ADC - unless there were 9.5 electrons of read noise, which I doubt there would be with a Sony sensor.

There are some tricks to still encoding the full dynamic range with a lower bit-depth ADC, but I don't know that any of them are actually employed at the CMOS level in today's cameras.

Link | Posted on Feb 27, 2017 at 01:00 UTC
In reply to:

Rishi Sanyal: No, I don't. And I have the science to prove it.

That's kind of the point of our studio tests... and Bill Claff's independent PTC/statistical analyses... no?

Anyway, not to burst anyone's bubble or ruin the surprise, but, [here you go](http://photonstophotos.net/Charts/PDR.htm#Nikon%20D810,Pentax%20645Z,Sony%20ILCE-7RII).

Bill Claff's excellent data/analysis show that you can get just as much dynamic range (well, 0.2 EV less, kind of within the margin of error) with a Nikon D810 (at ISO 64), and the BSI-FF sensor in the a7R II can do just as well in low light as the larger sensor in the 645Z. The same sensor used in the Fuji, to our knowledge.

Worse, you tend to have brighter lenses on FF, so that parity will actually sway in favor of the a7R II in low light once you use brighter lenses.

We also already showed the D810 to have similar dynamic range to the 645Z [here](http://bit.ly/2m07KoR) (full analysis [here](http://bit.ly/2m000Da).

You will get more resolution w/ the Fuji tho - bigger pixels put fewer demands on lens lp/mm.

Link | Posted on Feb 27, 2017 at 00:41 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Thunder123: Pro Photog says the A99ii nails AF - https://www.youtube.com/watch?time_continue=429&v=YqZWuygcTlQ

Patrick is a Sony Artisan so we can't have him run tests for our official review. That'd be unprecedented.

But we of course would love to work with him; I interviewed him at PIX and we seemed very much in alignment over how we think about cameras and the role of new technologies in these cameras.

Which reminds me, it appears we forgot to post that video...

Link | Posted on Feb 26, 2017 at 21:08 UTC
In reply to:

jlabate: I've always thought one of the appeals of medium format was 16-bit raw files but this Fuji sensor only has 14-bit. Anyone have thoughts on that?

Yes. I do. It only matters if your pixels have more than 14 EV of dynamic range. Until someone makes a measurement of full well capacity vs read noise per pixel on this camera, we won't know if it would have benefited from 16-bit ADC.

A Nikon D810, incidentally, would have though. But few cameras today would actually benefit from 16-bit ADCs. Mostly the very low megapixel ones, save for the D810.

It's complicated.

Link | Posted on Feb 25, 2017 at 05:47 UTC
In reply to:

Brad Trent: I honestly fail to see the point of a post like this. These sample photos tell me nothing. Zero. But fan boys wanna see samples, so, samples they will get! Until I get a side-by-side comparison with other medium format digital backs/cameras, this is just filler.

Dan's the man!

Link | Posted on Feb 25, 2017 at 05:41 UTC
In reply to:

Rishi Sanyal: No, I don't. And I have the science to prove it.

Thankfully, it's the one thing that works. Even in a post-factual era.

Link | Posted on Feb 24, 2017 at 09:06 UTC

No, I don't. And I have the science to prove it.

Link | Posted on Feb 24, 2017 at 06:45 UTC as 46th comment | 6 replies
On article Leica SL Review (860 comments in total)
In reply to:

WongFeiHong: Cons: Heavy and unbalanced with native lenses

Did this same Cons appear similarly in Sony exchangeable mirrorless cameras?

No, because they're not as heavy.

Link | Posted on Feb 23, 2017 at 22:56 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

entoman: The overall impression I get, from reading all the reviews, and all the forum comments here and elsewhere, is that the a99ii AF is CAPABLE of hitting focus accurately and tracking fast erratic subjects accurately, but that it requires very specific settings (and hence a lot of experience and a lot of familiarity with the Sony AF guidelines) in order to achieve a high keeper rate.

The point that many seem to be missing, is that some other systems, particularly Nikon's 3D tracking sytem in the D500, can achieve the same or better keeper rates, WITHOUT needing the myriad of "focus cases" used by Sony and Canon. The Nikon system just seems to work, straight out of the box. In other words, it is a more INTELLIGENT system, requiring less user input than either the Sony or Canon systems.

I have no personal experience of D500 or a99ii, but that is the overall impression I get from all the reviews and forum comments......

We did compare it to the D750, D810, 5D IV (worse: M5), a7R II, etc. Only time we mentioned a D5 is when we referred to the best in class in one regard.

As a reader, why WOULDN'T you want to know that? Especially when you can get similar performance in a D500 at half the price?

You'd rather we leave out information and not inform our readers? Sorry, we're not in the business of doing that. We want to frame technologies on the spectrum of best to worst.

Link | Posted on Feb 23, 2017 at 06:41 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Thunder123: Pro Photog says the A99ii nails AF - https://www.youtube.com/watch?time_continue=429&v=YqZWuygcTlQ

Patrick's a friend of ours - great guy. You'll note [he recommends](http://bit.ly/2kNfz1g) center AF point for best results, similar to our findings that it's more reliable than Lock-on.

He does recommend a setting of '5' for responsiveness, but when we tried '5' at basketball, it led to increased erraticism (since it can quickly jump off to a different subject if the main subject momentarily leaves the center AF point or another one enters it). This is why Sony's own 4D manual recommends a setting of 2 or 3 for fast moving approaching subjects (like the basketball scenarios we demonstrated).

So, in a sense, we were doing things as recommended, & these were our results.

That said, we'd like to try '5' w/ our bike test to see if it increases hit-rates, b/c we ourselves are surprised at the consistently low hit-rate across 26 different runs we performed (if people are curious, we're willing to make all files available).

We're waiting for new bodies/lenses + updates from Sony.

Link | Posted on Feb 22, 2017 at 20:50 UTC
On article Sony FE 100mm F2.8 STF bokeh demystified (353 comments in total)
In reply to:

abstractface: So Sony is saying I can fake medium format bokeh with this lens?

Medium format bokeh? What's that?

OP, please read @ThorstenMUC comment, which is right on the money.

Link | Posted on Feb 22, 2017 at 20:42 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

ttran88: To the authors,
Do you use face detection for the bicycle 🚴 test? Thanks

Hi ttran88: No, use either the center or a point near the center (we also initiate from center when testing subject tracking).

Link | Posted on Feb 21, 2017 at 23:54 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Thunder123: Youtube user nails AF on the A99ii - https://www.youtube.com/watch?v=qqL7jJsGRnw

I continue to have faith in our readership. :)

Link | Posted on Feb 21, 2017 at 06:46 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

lhkjacky: A99mk2 review by David Schloss (Digital Photo Pro)
https://youtu.be/6Xr_HEEyuDI

About David Schloss:
http://www.davidjschlossphoto.com/about

David is a good friend of ours, and contributor from time to time :) Great guy!

Link | Posted on Feb 21, 2017 at 01:03 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Ollum: @ Rishi Sanyal:

After reading all these comments are you still convinced everything was made right with the review of Sonys A99II?

A lot of users (here as well as other reviewers) tested the A99II directly against Canikon flagships and rated especially the AF performance as comparable.
It is obvious that your review of the AF is based either on a handling error or on a defective AF module. I personally disbelieve a handling error.

Have you contacted Sony and talked about the AF findings before you published the review? This is common scientific practice in such a case. Maybe they can ship a second body with a working AF module.

In each and every case the test has to be repeated with a second body or altered handling and the findings published regardless of whether the findings can be reproduced or not. Otherwise dpreview will suffer from credibility not only by Sony users. A lot of Canikon flagships users knows from own experience that Sony plays in the same league with the A99II.

DaveyWilson - how does my comment indicate I don't understand the AF system?

First of all, excuse me for saying this - but this is our job. Daily job, and some of us are highly trained in understanding complex systems. Understanding that 'Track Sensitivity' 1-5 determines how quickly (or not) the camera should respond when its phase sensor(s) suddenly sense a large change in phase is, well, not that difficult to understand.

It's not that there's this *just one* magical combination of settings that will *only* work for one scenario (& if that were the case, that'd be a problem relative to more robust systems). In this case, we actually used what Sony recommended (for our bike tests).

We also tried different settings in the real-world, & still experienced more erraticism than expected. As I've said, we're surprised (& disappointed), but these are our findings. We're attempting further investigation.

Our of curiosity, do you find any issues w/ the 1DXII AF? Have you used a D5 or D500?

Link | Posted on Feb 20, 2017 at 22:54 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Ollum: @ Rishi Sanyal:

After reading all these comments are you still convinced everything was made right with the review of Sonys A99II?

A lot of users (here as well as other reviewers) tested the A99II directly against Canikon flagships and rated especially the AF performance as comparable.
It is obvious that your review of the AF is based either on a handling error or on a defective AF module. I personally disbelieve a handling error.

Have you contacted Sony and talked about the AF findings before you published the review? This is common scientific practice in such a case. Maybe they can ship a second body with a working AF module.

In each and every case the test has to be repeated with a second body or altered handling and the findings published regardless of whether the findings can be reproduced or not. Otherwise dpreview will suffer from credibility not only by Sony users. A lot of Canikon flagships users knows from own experience that Sony plays in the same league with the A99II.

Photo Rob - No, only the first frame is in focus *if* you shoot at apertures smaller than or at F9, as that's where the OSPDAF system gives up. We specifically talk about this in our review.

Link | Posted on Feb 20, 2017 at 22:53 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Thunder123: Youtube user nails AF on the A99ii - https://www.youtube.com/watch?v=qqL7jJsGRnw

Doesn't show any 100% crops, but definitely nails AF...

Also, when we point out we experienced 'unreliability' with Lock-on, that doesn't it mean it *never* worked. It means that it failed often enough that we often didn't feel like we could rely on it.

You'll note we have a lot of in-focus shots in our gallery. That means we *can* get it to work; but our overall experience is that it's not as reliable as better systems.

Posting videos or links to *single* examples of things working don't immediately invalidate our findings. We also had situations where it worked. And situations where it didn't. We try to point out the latter to allow you, and Sony, to be aware of situations where things didn't work so well - particularly situations where some of the best of the competition typically do better.

Does this make sense?

Link | Posted on Feb 20, 2017 at 22:41 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Tequila MockingjayBird: These were taken using the a77ii

https://www.dpreview.com/forums/post/59150717

Sure, let me clarify:

@MonLov - when you see a similar behavior (in this case, jumpiness when enabling expanded AF modes, and unreliability of Lock-on AF) between two cameras that at least share one major component of the AF system, you're not entirely surprised when you witness similar behavior. That doesn't mean you don't test both separately though, which is why we did. Test both. Entirely independently.

@Thunder123: you're wrong; IR has the [same problems we did](http://www.imaging-resource.com/PRODS/sony-a77-ii/sony-a77-ii-field-test-part-ii.htm). It's remarkable how similar our experiences were: Sony told them to use Wide to get the best results, John immediately found that won't work for most photographers because you can't specify your subject; then, when he did use the Lock-on modes to specify his subject, too often the camera would jump to another subject, meaning Lock-on was unreliable.

Sounds remarkably like our experience, does it not?

Link | Posted on Feb 20, 2017 at 22:37 UTC
On article Sony SLT a99 II Review (1518 comments in total)
In reply to:

Luis Gabriel Photography: Why does the A7Rii look so out of focus on the comparison shots???? It should easily beat the IV and at least match the A99ii in sharpness comparing sensor to sensor so something is very odd about t.

That's literally possibly the only spot the a7R III looks worse. DOF issue slightly focused behind relative to others?

Link | Posted on Feb 20, 2017 at 07:25 UTC
Total: 4454, showing: 1 – 20
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