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No mirror-up mode on A7R...

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DavieK

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May sound like a silly title, but there is concern about the effect of the first curtain initial closure shutter shock on the A7R (I've done some IS tests and confirm that all is not well, even with Sony lenses with OSS).

The 2 second self-timer, which in comparable advanced/pro Alpha models lifts the mirror at the start of the timing then fires the shutter with minimal shock, just adds a delay and then fires the entire capping/first/second sequence as normal.

A firmware fix could, perhaps, either convert this 2 second mode to a shock-free release where the first curtain capping happens immediately - 2 seconds delay - exposure; or (less likely) could add a 'shutter closed' equivalent of 'mirror up', with first press closing the shutter, second press making the exposure.

Unlikely, because Sony would have to acknowledge there is a problem before doing a fix, and they are unlikely to agree that there is any problem.

David
 
Now you know why I never buy a new model camera when it is first released.

Let the bugs surface and get fixed, wait for the firmware to be done, secondhand prices to drop - then its time to buy.

Its probably the best time to buy a Nex7 at the moment!

I may well buy an A7 in two or three years time. :-P
 
The only way I can do a valid comparison is by using the NEX-5n with electronic first curtain, compared to the A7R with mechanical, and use the APS-C crop, together with 10-18mm, 18-55mm and 18-200mm Tamron lenses.

There is a possibility that the Sony 35mm, 28-75mm, 55mm etc behave differently to these OSS lenses and others have noted that OSS is actually disabled with some lens types on the A7R, so any test with the 10-18 and 18-200 (which definitely have OSS operating) is not going to help with the other lenses, none of which I can afford.

I've just done another small test following a flash of inspiration - when the camera is set to Speed Priority continuous, it's either using an electronic first curtain for all the frames after Frame 1, or a very different shutter cycle. Sure enough, just on an ad hoc test using the 18-200mm at 200mm and speeds around 1/60th, regular single frames or standard continuous show a double image much of the time, a clear 'jerk' creating not a camera shake blur but a distinct doubling. And frames taken using Speed Priority, with its very different shutter behaviour, don't have this.

I may have time to investigate further, and try to see exactly how the shutter behaviour changes. If it is as I suspect actually implementing an electronic first curtain, the next question is why this is not an option for regular shooting. I've tried the different bracket and multi-shot modes and the only continuous mode which appears to miss the double shutter action is Speed Priority.

David
 
No, focus and exposure are both locked. I think the only way I can find out what's happening will be a sound recording and analysis.

David
 
DavieK said:
The only way I can do a valid comparison is by using the NEX-5n with electronic first curtain, compared to the A7R with mechanical, and use the APS-C crop, together with 10-18mm, 18-55mm and 18-200mm Tamron lenses.

There is a possibility that the Sony 35mm, 28-75mm, 55mm etc behave differently to these OSS lenses and others have noted that OSS is actually disabled with some lens types on the A7R, so any test with the 10-18 and 18-200 (which definitely have OSS operating) is not going to help with the other lenses, none of which I can afford.

I've just done another small test following a flash of inspiration - when the camera is set to Speed Priority continuous, it's either using an electronic first curtain for all the frames after Frame 1, or a very different shutter cycle. Sure enough, just on an ad hoc test using the 18-200mm at 200mm and speeds around 1/60th, regular single frames or standard continuous show a double image much of the time, a clear 'jerk' creating not a camera shake blur but a distinct doubling. And frames taken using Speed Priority, with its very different shutter behaviour, don't have this.

I may have time to investigate further, and try to see exactly how the shutter behaviour changes. If it is as I suspect actually implementing an electronic first curtain, the next question is why this is not an option for regular shooting. I've tried the different bracket and multi-shot modes and the only continuous mode which appears to miss the double shutter action is Speed Priority.

David
Click to expand...
I don't think it is using an EFCS on continuous shooting, I think it just doesn't have to close the shutter an extra time, something like:

The sensor doesn't have an EFCS, so having a slight delay before the shutter opens, but after it closes 'could' be a potential 'cure' I guess.

My guess is instead of going:

Shutter press - shutter close - shutter open - exposure - shutter close - shutter open return to LV

This might be happening on say a three shot burst:

Shutter press - shutter close - shutter open - exposure - shutter close - pause - shutter open - exposure - shutter close - pause - shutter open - exposure - shutter close - shutter open return to LV

Having that slight pause between may well be enough of a cure, it worked for many Olympus users with this problem, by applying a small delay to the beginning of each exposure, it isn't much but made a difference.
 
The only thing is that the shutter doesn't run in two directions. I think Speed Priority is perhaps a 'normal' sequence - Frame 1, 2nd blind descends to cover sensor (step 1); both blinds return, capped, to charge shutter (step 2); exposure - 1st blind descends followed by 2nd forming either a slit or a fully uncovered period (step 3); both blinds now return capped to recharge (step 4); subsequent exposures - repeat steps 2 to 4 only. The captured frame is used to retain EVF view.

In contrast all other modes always use Steps 1 to 4, so before the exposure is made, one blind deploys then two blinds return capped. It's this double action which causes the jolt, and it looks as if Step 1 - the second blind firing on its own to cover the sensor - is the culprit. If so, the delay added to solve the problem would need to be between the capping, the shutter charging (both blinds overlapping return) and the exposure.

I think the A7R uses motorized rather than tensioned shutter action, but I'm not sure. If they are purely motorized, transit speeds could be changed in firmware or as you suggest an Olympus-style micro delay added to reposition the jolt.

David
 
1st off I don't believe the A7R has two shutters so the suggested approach may not work.

2nd, I've shot everything from an 8mm fisheye to a 600mm reflector on the A7R and haven't noticed any problems with vibration or impact on image quality!? As for shutter noise; no worse than any of my Canon cameras.

Maybe I just have a solider tripod than you?

bwa
 
Well, it's a problem on the M4/3 cameras so I wouldn't be surprised to see shutter shock on the A7r as well. One of the reasons I'm thinking of getting a NEX camera is for the electronic first curtain shutter, but now the Pana GM1 has one too so maybe they are getting their act together...
 
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