I'd like to have an SLT-mirror that flips up during the shot

Started Oct 1, 2012 | Discussions
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
I'd like to have an SLT-mirror that flips up during the shot
Oct 1, 2012

After looking at many comparison samples on the internet of NEX5N to A37/57 and NEX7 to A77 it becomes obvious that the translucent mirror adds noise, and I mean not because it "eats" some light, but mainly because it is an optical obstacle in front of the sensor that is not entirely clear like only lenses.

So why should Sony not take the best out of two worlds, keep the SLT for the great EVF and constant lifeview, but when you press the shutter it would flip up and give way for a free sensor? In my opinion this should not be a problem - except maybe that the continuous autofocus during bursts would become a little slower.

Since the SLT-mirror is much lighter than a traditional glass mirror, flipping up and down should go even faster with less vibration etc.

Any opinions?

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Sony Alpha NEX-5N Sony Alpha NEX-7 Sony SLT-A37 Sony SLT-A77
If you believe there are incorrect tags, please send us this post using our feedback form.
Rab G
Regular MemberPosts: 369
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Dirk W, Oct 1, 2012

Sorry but people could post pictures here and you would not be able to tell SLT from SLR!!

Reply   Reply with quote   Complain
Sam_Oslo
Senior MemberPosts: 2,413Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Dirk W, Oct 1, 2012

Dirk W wrote:

Since the SLT-mirror is much lighter than a traditional glass mirror, flipping up and down should go even faster with less vibration etc.

Any opinions?

You are asking big questions, but any answer would requires a deep understanding about highly technical details. But to put a complex matter in a simple way,

You should try using the Live View on a Canon, even the latest 650D with AF on sensor, to catch the point with SLT mirror.

Canon has just added a nice touch-screen, but the sloooooooooow AF makes LCD useless for composing action shots. The SLT is superior for video- AF too, but there is even more goodies in SLT mirror.

 Sam_Oslo's gear list:Sam_Oslo's gear list
Sony SLT-A77 Sony 50mm F1.4 Sony 20mm F2.8 Tamron SP AF 90mm F/2.8 Di Macro +2 more
Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Sam_Oslo, Oct 1, 2012

No reason to get arrogant here, why would you doubt my understanding about highly technical details?

If the SLT is down until you press the shutter, AF performance would be the same.

Taking video, the SLT could stay down for continuous AF, I am only talking about high quality pictures.

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
Prognathous
Veteran MemberPosts: 8,634
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Dirk W, Oct 1, 2012

Dirk W wrote:

After looking at many comparison samples on the internet of NEX5N to A37/57 and NEX7 to A77 it becomes obvious that the translucent mirror adds noise, and I mean not because it "eats" some light, but mainly because it is an optical obstacle in front of the sensor that is not entirely clear like only lenses.

If you compared shots taken at the same ISO then it's very likely that whatever difference you saw can be attributed to the SLT mirror loss of light (to the main sensor). Try comparing shots taken at 1/3 or 2/3 stop lower ISO than the A77.

So why should Sony not take the best out of two worlds, keep the SLT for the great EVF and constant lifeview, but when you press the shutter it would flip up and give way for a free sensor?

Probably because they don't think the tiny improvement in image quality/speed justifies the extra cost.

Personally, I'd be happy to have such an option - for two reasons - (1) the added speed can be a useful in some cases, when the shot is already on the verge of unusable due to noise, (2) it would ensure that no dirt on the mirror can effect the shot.

Since the SLT-mirror is much lighter than a traditional glass mirror, flipping up and down should go even faster with less vibration etc.

The thin mirror may more prone to breakage. Just guessing.

In any case, I don't expect Sony to do it unless they identify that they lose customers over not offering this option (as they did when they reverted from the Minolta-type hotshoe to the ancient ISO type that so many people seem to be attached to, pun not intended).

Prog.

Reply   Reply with quote   Complain
Sam_Oslo
Senior MemberPosts: 2,413Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Dirk W, Oct 1, 2012

Dirk W wrote:

No reason to get arrogant here, why would you doubt my understanding about highly technical details?

If the SLT is down until you press the shutter, AF performance would be the same.

Taking video, the SLT could stay down for continuous AF, I am only talking about high quality pictures.

If you understand what you are talking about, then tell em how the mirror can stay down for shot, and up for video? But don't try to speculate based on your misunderstandings. Base your claims on scientific and technical facts.

 Sam_Oslo's gear list:Sam_Oslo's gear list
Sony SLT-A77 Sony 50mm F1.4 Sony 20mm F2.8 Tamron SP AF 90mm F/2.8 Di Macro +2 more
Reply   Reply with quote   Complain
cyainparadise
Veteran MemberPosts: 5,577
Like?
It would require a major redesign
In reply to Dirk W, Oct 1, 2012

First, the existing mirror is too long.

Second, the mirror is made out of some kind of plastic.

Third, the flapping mirror would make noise.

I'm sure others will add to the list.

Reply   Reply with quote   Complain
cyainparadise
Veteran MemberPosts: 5,577
Like?
Forgot to mention...
In reply to cyainparadise, Oct 1, 2012

Fourth, the mirror is needed for the camera to AF. If it's flipping up, the camera cannot AF all the way to when the shutter opens.

Just take the mirror out and manual focus.

Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: Forgot to mention...
In reply to cyainparadise, Oct 1, 2012

Yeah but the last thing you mention is just like any ordinary SLR works, the AF works until you click the button, but in the moment of exposure the AF is set out of function.

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
Prognathous
Veteran MemberPosts: 8,634
Like?
Re: It would require a major redesign
In reply to cyainparadise, Oct 1, 2012

cyainparadise wrote:

First, the existing mirror is too long.

It's not like they don't have experience and reference designs of flipping mirrors. For sure though it won't come for free.

Second, the mirror is made out of some kind of plastic.

The point being?

Third, the flapping mirror would make noise.

It won't make noise when it stays down (in SLT mode). Obviously if you switch to SLR mode for the extra speed/quality you have to give up the SLT advantages.

Prog.
--
http://www.flickr.com/photos/oren_b

Reply   Reply with quote   Complain
Luebke
Forum MemberPosts: 79
Like?
Re: Forgot to mention...
In reply to cyainparadise, Oct 1, 2012

Your suggestion would combine disadvantages of both concepts without adding serious benefits.

  • higher costs than dslr (much higher mirror costs + dslr mechanism)

  • bigger size

  • higher weight

  • mirror vibrations (it's some kind of foil mirror, if you move it it vibrates)

  • slower speed (pictures / sec)

And all this for 1/3 to 1/2 f-stop?

Reply   Reply with quote   Complain
Prognathous
Veteran MemberPosts: 8,634
Like?
Re: Forgot to mention...
In reply to cyainparadise, Oct 1, 2012

cyainparadise wrote:

Fourth, the mirror is needed for the camera to AF. If it's flipping up, the camera cannot AF all the way to when the shutter opens.

How is that different than all other SLR's?

Just take the mirror out and manual focus.

No, the camera can AF before the mirror flips, and resume doing so immediately after exposure (when the mirror returns to it's lower position).

Prog.
--
http://www.flickr.com/photos/oren_b

Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Sam_Oslo, Oct 1, 2012

LOL you don seem to understand what I am writing.... I wrote the opposite, the mirror would stay down for video for continuous AF, and flip up for pictures. But, hey, never mind, technically too trivial I suppose.

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Prognathous, Oct 1, 2012

Prognathous wrote:

If you compared shots taken at the same ISO then it's very likely that whatever difference you saw can be attributed to the SLT mirror loss of light (to the main sensor). Try comparing shots taken at 1/3 or 2/3 stop lower ISO than the A77.

I see your point. So, for a real comparison, you would have to raise the studio light a little so that the shutter speed, aperture and ISO is the same on the SLT. I wonder though if that's not what they did at the Dpreview comparison link that I sent.

http://www.dpreview.com/reviews/studio-compare#baseDir=%2Freviews_data&cameraDataSubdir=boxshot&indexFileName=boxshotindex.xml&presetsFileName=boxshotpresets.xml&showDescriptions=false&headerTitle=Studio%20scene&headerSubTitle=Standard%20studio%20scene%20comparison&masterCamera=sony_slta57&masterSample=dsc00312.acr&slotsCount=4&slot0Camera=sony_slta57&slot0Sample=dsc00312.acr&slot0DisableCameraSelection=true&slot0DisableSampleSelection=true&slot0LinkWithMaster=true&slot1Camera=sony_nex5n&slot1Sample=dsc00790.acr&slot2Camera=sony_slta77&slot2Sample=dsc02823_2.acr&slot3Camera=sony_nex7&slot3Sample=dsc03038.acr&x=0.169665195560462&y=-0.31267358461293626&extraCameraCount=0

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: Forgot to mention...
In reply to Luebke, Oct 1, 2012

It's not for the f-stop, it's for the lower noise especially in high ISOs, and that is a very important issue if priority is to get the maximum IQ out of the sensor.

Bigger size, weight and cost - if so then marginal. Vibrations - agreed, but that's only an issue in very special situations and can be tackled by mirror lock up. Slower speed - agreed.

The optimum would be if you could chose between SLT-mode and flip-mode.

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
rothwells
Regular MemberPosts: 290Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to Dirk W, Oct 1, 2012

Dirk W wrote:

LOL you don seem to understand what I am writing.... I wrote the opposite, the mirror would stay down for video for continuous AF, and flip up for pictures. But, hey, never mind, technically too trivial I suppose.

But.... Isn't..... That,..... An..... SLR?

 rothwells's gear list:rothwells's gear list
Sony SLT-A77 Sony 70-200mm F2.8 G Sony DT 35mm F1.8 SAM Sony DT 16-50mm F2.8 SSM
Reply   Reply with quote   Complain
Luebke
Forum MemberPosts: 79
Like?
Re: Forgot to mention...
In reply to Dirk W, Oct 1, 2012

Dirk W wrote:

It's not for the f-stop, it's for the lower noise especially in high ISOs, and that is a very important issue if priority is to get the maximum IQ out of the sensor.

Bigger size, weight and cost - if so then marginal. Vibrations - agreed, but that's only an issue in very special situations and can be tackled by mirror lock up. Slower speed - agreed.

The optimum would be if you could chose between SLT-mode and flip-mode.

I think a SLT with flipping mirror will never be realized. It would be too special or too expensive for the mass market compared to normal SLTs.

But maybe we will see an alpha with good and fast on chip PDAF. An APS-C A-Mount J1 would seem to fit your needs. You might need to sacrifice some pixels due to the PDAF but that seems reasonable to me. Or a NEX-6 with a good mirrorless adapter (a pimped LA-EA1) would do it.

Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: Forgot to mention...
In reply to Luebke, Oct 1, 2012

Yeah I agree that would be the best solution and hopefully the future - a superfast on chip PDAF. Less mechanics is always better. But until then - the SLT still seems to be necessary for fast af.

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
Dirk W
Senior MemberPosts: 1,375Gear list
Like?
Re: I'd like to have an SLT-mirror that flips up during the shot
In reply to rothwells, Oct 1, 2012

Kind of..... but as I wrote - the best out of two worlds: with the translucent mirror you would have the constant lifeview and thus the fantastic EVF. And - in video mode, leaving the mirror down - continuous PDAF.

 Dirk W's gear list:Dirk W's gear list
Sony Alpha NEX-5N Sony Alpha NEX-6 Sony Alpha NEX-3N A3000 Sony 70-400mm F4-5.6 G SSM +7 more
Reply   Reply with quote   Complain
Keyboard shortcuts:
FForum MMy threads