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Guillermo Luijk

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Can the Sony A7R be an option to digital backs?
« on: November 01, 2013, 02:04:49 pm »

Looking at the level of detail (even if those JPEG were a bit over sharpened) that 36Mpx Sony sensors without AA filter can produce in optimal conditions (high resolution glass, accurate focus, and absence of camera shake blur or diffraction):




I wondered how they compare to a digital back designed for studio work. Comparing the A7R sensor (36Mpx) with the ultimate backs: Phase One IQ 180 (80Mpx) and Hasselblad H3DII 50 (50Mpx) regarding different sensor parameters:


ISO:


ISO values in the backs are typical for their intended use: very low ISO values to maximize image quality under controlled lighting situations where getting a good exposure will never be a restriction.

The Phase One begins at an amazingly low (for those of us used to a typical DSLR scale) real ISO29, keeping that value up to a ISO100 user setting. From that point ISO pushes up to ISO3200, surely through software RAW level scaling.

Hasselblad sensor is even more honest, it keeps a real ISO47 in the whole user scale from ISO50 to ISO400.

The A7R however begins at a real ISO73 when ISO100 is set, simulating ISO50 via metadata and reaching ISO25600 in the right adjustable end.

So regarding ISO no surprise, beginning at lower real ISO gains will help the backs to get the best from their sensors in the controlled situations they were designed for.


Noise in areas with a good exposure:


We can see that performance for a given real ISO, and once different resolutions have been weighted (DxOMark 'Print' mode), is the same for the three sensors.

Since the lowest available real ISO is lower in the Phase One (29 vs 47 and 73), those applications where a correct exposure can be obtained at the lowest ISO will benefit from an almost negligible 1/2 stop improvement in the Phase One over the Hassel and the A7R.

This parameter is important regarding noise when dark areas are not going to be lifted in post processing (in other words, when the JPEG straight from the camera is fine in terms of exposure), which is typical in studio applications to which these digital backs are aimed.


Noise in dark areas:


When comparig Dynamic range, or in other words the ability to lift shadows preventing noise from appearing, the A7R Sony technology clearly beats the backs by 2 stops (and that is much) for any given real ISO.

Again, if the application allows correct exposure at the lowest ISO, the lower ISO in the backs will reduce that advantage: Phase One will only be 1/2 stop below the Sony performance and Hasselblad 1,5 stops worse than the A7R.

In tripod applications with high contrast scenes (landscape, architecture) is where this parameter matters, and places the A7R sensor as the best performer. If the optics used allow to get the same real effective level of detail in the FF sensor or close (and here the diffraction/DOF trade-off plays a role in reducing the initial pixel count advantage of the backs), we could even conclude that the A7R could be the best candidate in these large DOF applications.



Please note that this was only a sensor performance comparision. It doesn't take into account output Mpx, optics, the advantage of larger formats in DOF control or the so called "3D look" in shallow DOF images using large formats. It doesn't take into account any value for money consideration though :D

Regards
« Last Edit: November 01, 2013, 05:34:37 pm by Guillermo Luijk »
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TMARK

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Re: Can the Sony A7R be an option to digital backs?
« Reply #1 on: November 01, 2013, 02:12:06 pm »

Sort of like the D800e?  But of course no mirror.

Does the A7r sensor havr any sort of OLP filter?  The D800e of course has an OLP filter, tuned for sharpness. 

Thanks
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AFairley

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Re: Can the Sony A7R be an option to digital backs?
« Reply #2 on: November 01, 2013, 04:54:02 pm »

No OLP on the A7r -- but whether this means nothing at all or the "do then undo" system in the D800E I have not seen discussed anywhere.
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Guillermo Luijk

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Re: Can the Sony A7R be an option to digital backs?
« Reply #3 on: November 01, 2013, 05:32:50 pm »

No OLP on the A7r -- but whether this means nothing at all or the "do then undo" system in the D800E I have not seen discussed anywhere.
It will be interesting to see the first DxOMark tests about optical resolution of the A7R with the same lenses as in the D800E.

ErikKaffehr

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Re: Can the Sony A7R be an option to digital backs?
« Reply #4 on: November 02, 2013, 01:02:52 am »

Hi,

I have seen the posted samples. I don't know if they say anything about resolution. The crop is probably a central one, where most lenses are pretty sharp. It is oversharpened. Aliasing will add some fake detail, I may think that some of the oversharpening may come from those aliases. Some of the skin structure may be fake in my guess.

On the other hand, the only way to make a 36MP sensor bad is a bad lens. If lenses are good the A7r would be good.

Regarding DR, I have a Sony Alpha 99, which shares sensor with the A7. I am also shooting with a Phase One P45+. Lifting shadows on the P45+ is problematic compared with the Alpha 99. But, I guess that the lenses I use on the Alpha have more flare and that flare covers some of the noise floor.

Would be interesting to compare the Alpha 7r with my P45+. My guess is really that a 40 MP MFD with excellent lenses would have a bit more bite. I still feel that MFD needs to go CMOS and smaller pixels.

Best regards
Erik


Looking at the level of detail (even if those JPEG were a bit over sharpened) that 36Mpx Sony sensors without AA filter can produce in optimal conditions (high resolution glass, accurate focus, and absence of camera shake blur or diffraction):




I wondered how they compare to a digital back designed for studio work. Comparing the A7R sensor (36Mpx) with the ultimate backs: Phase One IQ 180 (80Mpx) and Hasselblad H3DII 50 (50Mpx) regarding different sensor parameters:


ISO:


ISO values in the backs are typical for their intended use: very low ISO values to maximize image quality under controlled lighting situations where getting a good exposure will never be a restriction.

The Phase One begins at an amazingly low (for those of us used to a typical DSLR scale) real ISO29, keeping that value up to a ISO100 user setting. From that point ISO pushes up to ISO3200, surely through software RAW level scaling.

Hasselblad sensor is even more honest, it keeps a real ISO47 in the whole user scale from ISO50 to ISO400.

The A7R however begins at a real ISO73 when ISO100 is set, simulating ISO50 via metadata and reaching ISO25600 in the right adjustable end.

So regarding ISO no surprise, beginning at lower real ISO gains will help the backs to get the best from their sensors in the controlled situations they were designed for.


Noise in areas with a good exposure:


We can see that performance for a given real ISO, and once different resolutions have been weighted (DxOMark 'Print' mode), is the same for the three sensors.

Since the lowest available real ISO is lower in the Phase One (29 vs 47 and 73), those applications where a correct exposure can be obtained at the lowest ISO will benefit from an almost negligible 1/2 stop improvement in the Phase One over the Hassel and the A7R.

This parameter is important regarding noise when dark areas are not going to be lifted in post processing (in other words, when the JPEG straight from the camera is fine in terms of exposure), which is typical in studio applications to which these digital backs are aimed.


Noise in dark areas:


When comparig Dynamic range, or in other words the ability to lift shadows preventing noise from appearing, the A7R Sony technology clearly beats the backs by 2 stops (and that is much) for any given real ISO.

Again, if the application allows correct exposure at the lowest ISO, the lower ISO in the backs will reduce that advantage: Phase One will only be 0,5 stops below the Sony performance and Hasselblad 1,5 stops worse than the A7R.

In tripod applications with high contrast scenes (landscape, architecture) is where this parameter matters, and places the A7R sensor as the best performer. If the optics used allow to get the same real effective level of detail in the FF sensor or close (and here the diffraction/DOF trade-off plays a role in reducing the initial pixel count advantage of the backs), we could even conclude that the A7R could be the best candidate in these large DOF applications.



Please note that this was only a sensor performance comparision. It doesn't take into account output Mpx, optics, the advantage of larger formats in DOF control or the so called "3D effect" in shallow DOF images using large formats. It also doesn't take into account any value for money approach though :D

Regards

« Last Edit: November 02, 2013, 01:05:36 am by ErikKaffehr »
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Erik Kaffehr
 

EgillBjarki

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Re: Can the Sony A7R be an option to digital backs?
« Reply #5 on: November 02, 2013, 01:48:04 am »

This all comes down to the right equipment for the right job.

In the last few years, DSLR makers made it easier for me to replace medium format. I shot MFD some years ago. Do I miss it? When I have my Canon on a tripod shooting landscapes, I admit, I do. In just about all other cases, I don't.

I am curious to see how the current and future lenses perform on the A7R. These details on especially dynamic range, are really attractive!

But, IF the lens options and performance is poor, these measurements are just attractive numbers on a spec sheet...
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Sareesh Sudhakaran

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Re: Can the Sony A7R be an option to digital backs?
« Reply #6 on: November 02, 2013, 04:22:02 am »

It will be interesting to see the first DxOMark tests about optical resolution of the A7R with the same lenses as in the D800E.

It's the same sensor - same performance. http://www.dxomark.com/Reviews/Sony-Alpha-7R-review-Highest-ever-full-frame-image-quality
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Bart_van_der_Wolf

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Re: Can the Sony A7R be an option to digital backs?
« Reply #7 on: November 02, 2013, 04:56:50 am »

It's the same sensor - same performance. http://www.dxomark.com/Reviews/Sony-Alpha-7R-review-Highest-ever-full-frame-image-quality

Hi Sareesh,

Looking at the measurement results, it certainly looks like it. RawDigger (version 0.9.20) can reveal the Raw file data of the masked sensels, which confirms the sensel layout is identical. Of course, the supporting electronics are probably different, so that may produce (small) differences, but the differences seem to be insignificant.

From an optical perspective we do not know how Sony solved the issue with the OLPF sandwich. Maybe they left it out, which would have a different effect on the lens-design requirements than replacing it with some other material. Companies like Canon have been updating their lens-line with improved designs, presumably with the assumption that an OLPF package is present. We also do not know if they use a different IR fiter.

Cheers,
Bart
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BernardLanguillier

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Re: Can the Sony A7R be an option to digital backs?
« Reply #8 on: November 02, 2013, 08:28:38 am »

ISO:


ISO values in the backs are typical for their intended use: very low ISO values to maximize image quality under controlled lighting situations where getting a good exposure will never be a restriction.

The Phase One begins at an amazingly low (for those of us used to a typical DSLR scale) real ISO29, keeping that value up to a ISO100 user setting.

Meaning that when shooting at ISO 100 and above with a IQ180, you are in fact nearly under-exposing 2 stops. No wonder that users marvel at the "highlight" headroom.  ;D

Cheers,
Bernard
« Last Edit: November 02, 2013, 08:30:16 am by BernardLanguillier »
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Bart_van_der_Wolf

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Re: Can the Sony A7R be an option to digital backs?
« Reply #9 on: November 02, 2013, 09:27:31 am »

Meaning that when shooting at ISO 100 and above with a IQ180, you are in fact nearly under-exposing 2 stops. No wonder that users marvel at the "highlight" headroom.  ;D

Hi Bernard,

And then add a stop of EV push in postprocessing, by using the film-curve response preset...
How non-digital those highlights look, must be the sensor. ;D

Cheers,
Bart
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Guillermo Luijk

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Re: Re: Re: Can the Sony A7R be an option to digital backs?
« Reply #10 on: November 02, 2013, 09:37:04 am »

Meaning that when shooting at ISO 100 and above with a IQ180, you are in fact nearly under-exposing 2 stops. No wonder that users marvel at the "highlight" headroom.  ;D

Not to mention the Hassel at ISO400.

bcooter

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Re: Can the Sony A7R be an option to digital backs?
« Reply #11 on: November 02, 2013, 09:54:44 am »






I haven't tried the A7 so this is conjecture, but the trick of making any digital camera look good is to shoot a head a shoulders portrait with a fast duration flash.

Any camera with a lightweight or no AA filter will show these results, or results so close that few can ever tell the difference.  My 21 mpX phase back and contax will do this level of detail in this situtaiton and that's a very old camera and digital back.

It's funny, everybody pixel peeps on these forums until they bleed, but sharpness and detail means nothing without sharp focus and either high shutter speeds, fast flash duration or a secure tripod will do as much for detail as any gain in megapixels.

These two images are very different from the images posted on DP review from a press junket showing continuous light images.  Those showed at lot of issues resolving certain areas from 200 to 800 iso.

I was actually very interested in this camera until I saw those samples and read the video specs even though I own a good collection of new A mount lenses, so buying in wouldn't be a great leap for me.

I'm not saying the A7(R) isn't a good camera and obviously it's a hell of a trick to make an interchangable lens camera in this size, but  a lot depends on where Sony goes with it.  

Is the E mount their new professional standard, or better put is it targeted to the professional at all?

Will this be complimented by a large A series camera, will there be crossover on video either with a higher spec e-mount camera or an A7 with higher video specs?

Sometimes I don't think Sony even knows where there going, which is one of the reasons they are bleeding red ink and this week their stock was downgraded.

In fact i think Sony seems to do what a lot of electronic camera makers do.  They introduce new product, trying hard not to overstep their other products like current 4k video cameras and even their own A system.

The e mount kind of throws me, because Sony is obviously targeting photographers that currently have either Nikon, Canon or medium format digital systems and if your a stills only Nikon guy, what would move you to go from a d800 to this camera, other than body size?

I personally think this is a bridge camera and whether still photographers like it or not, the next series of cameras to hit the shelves is going to feature 4k video along with high quality stills.

Anyway, time will tell.

IMO

BC

P.S.

These two images shot with a p30 and Contax and the second with a canon 1ds2.   Once again old cameras and the originals had almost too much detail for this type of session, so flash allows for a lot of detail.
The first image with profoto flash, the bottom with Arri tungsten.



« Last Edit: November 02, 2013, 10:27:14 am by bcooter »
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ErikKaffehr

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Re: Can the Sony A7R be an option to digital backs?
« Reply #12 on: November 02, 2013, 10:46:46 am »

Hi,

I guess that Sony doesn't exactly now where they are going. I would say that Sony does lack the consistency to be a professional camera. Minolta did make a few great cameras, like the XM and the Dynax 9, but there were long times without a serious camera.

The A7 leaves room for an A9 in the Sony/Minolta naming system. I guess that Sony looks for a niche where they can grow. Canon and Nikon have a firm grip on the professional market and that is hard to crack.

On the other hand, MFD seems also have some problem. They are to expensive. Some photographers seem to think that 25 MP is enough, those photographers won't buy into backs with 80MP costing 400 k$US. I would suggest that making 80MP backs at 10k$USD would make a lot of sense.

My religion forbids me to like low res backs without OLP-filters, so I think you need high resolution to keep aliasing away. That is a religious thing, sorry!

Best regards
Erik



I haven't tried the A7 so this is conjecture, but the trick of making any digital camera look good is to shoot a head a shoulders portrait with a fast duration flash.

Any camera with a lightweight or no AA filter will show these results, or results so close that few can ever tell the difference.  My 21 mpX phase back and contax will do this level of detail in this situtaiton and that's a very old camera and digital back.

It's funny, everybody pixel peeps on these forums until they bleed, but sharpness and detail means nothing without sharp focus and either high shutter speeds, fast flash duration or a secure tripod will do as much for detail as any gain in megapixels.

These two images are very different from the images posted on DP review from a press junket showing continuous light images.  Those showed at lot of issues resolving certain areas from 200 to 800 iso.

I was actually very interested in this camera until I saw those samples and read the video specs even though I own a good collection of new A mount lenses, so buying in wouldn't be a great leap for me.

I'm not saying the A7(R) isn't a good camera and obviously it's a hell of a trick to make an interchangable lens camera in this size, but  a lot depends on where Sony goes with it.  

Is the E mount their new professional standard, or better put is it targeted to the professional at all?

Will this be complimented by a large A series camera, will there be crossover on video either with a higher spec e-mount camera or an A7 with higher video specs?

Sometimes I don't think Sony even knows where there going, which is one of the reasons they are bleeding red ink and this week their stock was downgraded.

In fact i think Sony seems to do what a lot of electronic camera makers do.  They introduce new product, trying hard not to overstep their other products like current 4k video cameras and even their own A system.

The e mount kind of throws me, because Sony is obviously targeting photographers that currently have either Nikon, Canon or medium format digital systems and if your a stills only Nikon guy, what would move you to go from a d800 to this camera, other than body size?

I personally think this is a bridge camera and whether still photographers like it or not, the next series of cameras to hit the shelves is going to feature 4k video along with high quality stills.

Anyway, time will tell.

IMO

BC

P.S.

These two images shot with a p30 and Contax and the second with a canon 1ds2.   Once again old cameras and the originals had almost too much detail for this type of session, so flash allows for a lot of detail.
The first image with profoto flash, the bottom with Arri tungsten.




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Erik Kaffehr
 

TMARK

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Re: Can the Sony A7R be an option to digital backs?
« Reply #13 on: November 02, 2013, 04:38:32 pm »

I used to attend these product demos at Able Cinetech, which was our go to for motion gear.  We were using the Sony EXs for certain projects where the Red was too big.  This was pre-5d2.  At the Sony demo we asked questions about Sony's plans for the EX series.  The response was very honest:  "We don't know."  Here is why:  Each group in Sony comes up with the best product they can, then they press forward with whatever sells and cut what doesn't, with no coherent roadmap or marketing strategy.  The internal competition is intense.  The A900 and EX video cams were put together in Long Island.  They have similar color response because it was shared within the facility.  A strange way to operate.

I haven't tried the A7 so this is conjecture, but the trick of making any digital camera look good is to shoot a head a shoulders portrait with a fast duration flash.

Any camera with a lightweight or no AA filter will show these results, or results so close that few can ever tell the difference.  My 21 mpX phase back and contax will do this level of detail in this situtaiton and that's a very old camera and digital back.

It's funny, everybody pixel peeps on these forums until they bleed, but sharpness and detail means nothing without sharp focus and either high shutter speeds, fast flash duration or a secure tripod will do as much for detail as any gain in megapixels.

These two images are very different from the images posted on DP review from a press junket showing continuous light images.  Those showed at lot of issues resolving certain areas from 200 to 800 iso.

I was actually very interested in this camera until I saw those samples and read the video specs even though I own a good collection of new A mount lenses, so buying in wouldn't be a great leap for me.

I'm not saying the A7(R) isn't a good camera and obviously it's a hell of a trick to make an interchangable lens camera in this size, but  a lot depends on where Sony goes with it.  

Is the E mount their new professional standard, or better put is it targeted to the professional at all?

Will this be complimented by a large A series camera, will there be crossover on video either with a higher spec e-mount camera or an A7 with higher video specs?

Sometimes I don't think Sony even knows where there going, which is one of the reasons they are bleeding red ink and this week their stock was downgraded.

In fact i think Sony seems to do what a lot of electronic camera makers do.  They introduce new product, trying hard not to overstep their other products like current 4k video cameras and even their own A system.

The e mount kind of throws me, because Sony is obviously targeting photographers that currently have either Nikon, Canon or medium format digital systems and if your a stills only Nikon guy, what would move you to go from a d800 to this camera, other than body size?

I personally think this is a bridge camera and whether still photographers like it or not, the next series of cameras to hit the shelves is going to feature 4k video along with high quality stills.

Anyway, time will tell.

IMO

BC

P.S.

These two images shot with a p30 and Contax and the second with a canon 1ds2.   Once again old cameras and the originals had almost too much detail for this type of session, so flash allows for a lot of detail.
The first image with profoto flash, the bottom with Arri tungsten.



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bcooter

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Re: Can the Sony A7R be an option to digital backs?
« Reply #14 on: November 02, 2013, 10:46:35 pm »

I've picked up a dozen Sony cameras with the intention on buying video and still.

The video cameras were built like jewels, but shot . . . very video looking video.

The still cameras just were never there for me.

Then they came out with an af100 and I had a gig I needed autofocus and a smaller form factor than the RED 1's, and honestly didn't get a chance to test it, just bought it and hit the road.

Turns out the camera was 70% there.  The form factor was perfect, the autofocus very good for most of what I needed, but the file was as thin as a Somali pirate, the build quality had dropped to Yugo standards  and the e-mount lenses we're not that fast so I bought A mounts, and that silly adapter that locks the camera at f3 or 3.5 or something like that,  though that was ok because I always shot at 3.5 anyway.  But bottom line and 7 grand later it sets in the case rarely used.

7 grand isn't sofa change, but that's not the problem.  The problem is you know they can do much much much better.  Crap, those little gh3's shoot a file that in comparison looks like I talked Arri into building me a 14 bit 4k camera and threw in a lifetime pass at technicolor for the grading.  BTW:  The panasonics are almost sofa change.

We know sony can make anything, but none of us know when how long or better yet, what market they'll target next.  



I used to attend these product demos at Able Cinetech, which was our go to for motion gear.  We were using the Sony EXs for certain projects where the Red was too big.  This was pre-5d2.  At the Sony demo we asked questions about Sony's plans for the EX series.  The response was very honest:  "We don't know."  Here is why:  Each group in Sony comes up with the best product they can, then they press forward with whatever sells and cut what doesn't, with no coherent roadmap or marketing strategy.  The internal competition is intense.  The A900 and EX video cams were put together in Long Island.  They have similar color response because it was shared within the facility.  A strange way to operate.

« Last Edit: November 03, 2013, 12:29:31 am by bcooter »
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Christoph C. Feldhaim

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Re: Can the Sony A7R be an option to digital backs?
« Reply #15 on: November 03, 2013, 04:14:20 am »

I haven't tried the A7 so this is conjecture, but the trick of making any digital camera look good is to shoot a head a shoulders portrait with a fast duration flash.


Could you elaborate on that?
Is it the short exposure time eliminating slight movements?
Are not all flashes created equal? (concerning time)
I always thought flash already is so fast you can do highspeed photography with it.
Just curious ...

Cheers
~Chris

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Amplifying less before ADC to better preserve highlights is not underexposing
« Reply #16 on: November 03, 2013, 09:45:15 am »

Meaning that when shooting at ISO 100 and above with a IQ180, you are in fact nearly under-exposing 2 stops. No wonder that users marvel at the "highlight" headroom.  ;D
Can we drop this myth where "applying analog amplification before ADC which leaves more that the MINIMUM amount of highlight headroom recommended by the ISO standard for saturation-based MINIMUM safe exposure index" gets characterized as a defect or deception with phrasing like "underexposure", "over-stating ISO", or even "cheating on ISO". Try reading and and understanding what ISO standard 12232:2006 says and means.

For one thing, the differences between the raw-level saturation-based exposure index values measured by DxO and the exposure index values on the camera's "ISO" dial does _not_ mean that different cameras are giving the sensor vastly different amount of exposure at the same settings; the DxOs tests I have looked at indicated that all in-camera metering is instead working in accord with ISO standards for exposure index.

What is happening instead is that different cameras then apply different degrees of analog gain to the sensor's signals before ADC, leaving different amounts of highlight headroom in their raw output levels. In particular, many MF cameras with CCD sensors of 12-13 stops DR and the only opportunity for variable amplification coming off-board, right next to the 16-bit off-board ADCs have about three stops of latitude to achieve two desirable goals simultaneously:
- gain and ADC level placement high enough that the noise level in the output of the amplifier is well above the level of any subsequent noise sources, which with CCDs is mainly quantization noise from the 16-bit ADC;
- gain and ADC level placement low enough that a full-well signal goes to a voltage within the range of the ADC, avoiding any "highlight clipping" from the amplifier/ADC combination.

It is hard to see any benefit that would be achieved by amplifying more, such as from the misguided ideal of placing metered mid-tones at the ISO-recommended minimum distance below maximum. Note for example thing that 16 bit ADC output with mid-tones placed one stops below that recommended maximum level has all numerical ADC output levels twice as high as 14-bit with mid-tones placed at that recommended maximum, so there is still likely less quantization noise.

The situation is different for cameras that use active pixel CMOS sensors with the ability to apply variable gain very early, during the signal transfer from photo-sites to sense capacitors at the edge of the sensor, and there is also a far smaller gap between stops of sensor DR and bits of ADC accuracy; in some cases it seems that photo-site DR might even be greater than the ADC's effective DR. That on-sensor gain is applied early enough that it can protect the signal against noise that arises later, such as during transport to the ADC and in the 12 or 14 bit ADC itself; thus it can make sense in low-light [high ISO] situations to amplify so much that full-well signals would get clipped, because such bright pixels are very unlikely.


TL;DR: I suggest that different approaches between CCD MF backs and most CMOS DSLRs are different but equally rational design responses to the different characteristics of the sensors, amplification and ADC, not evidence of "lying" or "cheating" or "overstating the ISO" or "underexposing".

Given that blown highlights are overall a far more common and clearly visible defect in digital photography than noise in deep shadows that will in most cases print (or show on-screen) as pure black, and that indeed blown highlights due to the "hard-clipping" is the one place that digital images are most often worse than film, I find it strange that people are so critical of a design feature that makes it easier to avoid that problem --- especially when it is done in a way that does not make visible noise levels any worse. (Indeed, Bernard, I have noticed that when you post some of your wonderful landscape images, the most common technical criticism is of blown highlights.)
« Last Edit: November 03, 2013, 09:46:56 am by BJL »
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TMARK

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Re: Can the Sony A7R be an option to digital backs?
« Reply #17 on: November 03, 2013, 04:47:15 pm »

The flash duration becomes the effective exposure time. Some strobe systems have long durations, such as 1/200 a second. Short durations, such as 1/1100, stops (almost) all movement.   Also at work are optimal aperture settings and hard light, which both contribute to high resolution no matter the camera.



Could you elaborate on that?
Is it the short exposure time eliminating slight movements?
Are not all flashes created equal? (concerning time)
I always thought flash already is so fast you can do highspeed photography with it.
Just curious ...

Cheers
~Chris
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bcooter

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Re: Can the Sony A7R be an option to digital backs?
« Reply #18 on: November 03, 2013, 09:00:43 pm »

T's right about duration, but most flash is going to run around 1.200th a small flash 5 times that.  Also hard light accentuates detail.

Thing is this camera may be great, but the samples are never representative.

They all do it, so Sony isn't alone in questionable samples and testing, though either 20 seconds a shot press junkets or demos with consultants.

I dig the form factor, has less faith in the color, lesser faith in the e mount lens systems, but would love to be proven wrong, because if it tethers (like I've heard), has detail, runs fast and is durable, this is just about the right size of a 35mm camera with professional aspirations.

I guess we'll see, but Sony more than any large marker, needs to make a big noise to get some attention.

IMO

BC
« Last Edit: November 03, 2013, 10:33:48 pm by bcooter »
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