A99 shutter cycle - can owners pleae help me with a test?

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David Kilpatrick
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by David Kilpatrick »

I didn't see any positive confirmation just vague 'mine isn't like that' messages and pms from people who assured me my camera must be faulty and should be returned. People see what they want to see and hear what they want to hear. But I probably wouldn't put any of them in an orchestra.

Flash test - sorry Greg, the little adaptor got lost for a few days (found it attached to HVL-F20AM) as of course it will for most users, as there is no place to put it and it doesn't even come with a pouch or case. I do not have the HVL-F60AM or intend to get it so the HVL-F58AM needs the adaptor to work.

Anyway, here are the figures - ADI or PreFlash TTL used in electronic first curtain mode produces only a single visible flash, no apparent pre-burst, and adds 130ms to the overall shutter cycle. The total duration of audible sound is around half a second with flash, 1/3 second without. Enabling mechanical first shutter curtain produces two visible bursts, one before the curtain closes before exposure presumably for measurement, and increases the overall shutter cycle by 60ms or maybe a little more. The total shutter cycle in this mode is around 580ms.

There is no apparent delay if you shoot manual flash using the electronic first curtain. The flash adds under 15ms to the overall cycle and fires right at the moment you press the shutter. That's 1/60th of a second or less to 'talk' to the flash for manual sync.

Also, all the TTL tests I did - provided an ISO and aperture within the expected range were set - produce good exposure and normal histogram.

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by Greg Beetham »

Thanks for that David, now I’m suffering information overload I think, with over half a second shutter cycle time with the mechanical first curtain when using an oem flash it seems like there are some accommodations going on there for some reason, I’m guessing that it’s a flash regulation issue that has to be sorted with the mechanical shutter movement that doesn’t exist with the electronic shutter.
The reason I asked about 1/250sec sync was there was a dpr discussion thread about the A99 using an Einstein studio set that was causing a black bar across the top of the frame when used with radio triggers but was apparently ok at that speed when used with an oem flash to trigger the studio via a photo cell (which the photographer wanted to avoid), all with electronic first curtain (I think from memory).
The only thing I could think of was there were two different versions of 1/250sec shutter, a version that was fully open and one that wasn’t, and it was only fully open when there was an oem flash in the mix, and that is the reason why I thought some measurements of the shutter duration at that speed with and without an oem flash being used would reveal if there was any difference in elapsed time.
But with me not putting thinking cap on straight, I have since realized it might not be possible to accurately measure the cycle time when the electronic first curtain is in use.
Anyway thanks once again.
Greg
Ps yes there were a couple or three who thought that the shutter didn’t vary and couldn’t detect the EVF blackout difference either, but I’m sure there were some a couple of hours later who did notice.
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by David Kilpatrick »

I don't have any problem understanding how that works. Radio triggers introduce latency through their use of digital processing, optical triggers like my Wein kit have zero latency and work at the speed of light. It's always a risk trying to sync studio flash at 1/250th; most units can not be reliably synced at that speed, and have much longer T=0.5 durations than their specs imply.

There is no such things as a simple X-synch left in any camera now. It's all microprocessor controlled, and the A99 is probably one of the more complex systems.

What matters is that is you shoot with electronic first curtain, you do not get a pre-burst, you get effectively instant exposure and you also get accurate exposure. That makes it the best camera for flash in the entire digital generation to date. The long shutter cycle all happens AFTER the exposure, except for the initial 1/60th which seems to be the handshake with the flashgun.

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by pakodominguez »

David Kilpatrick wrote:That makes it the best camera for flash in the entire digital generation to date.
Overall? or "just" Minolta/Sony cameras?
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by David Kilpatrick »

Minolta/Sony Pako, but actually, it's no more delayed than any other make. I tried both Pre-Flash TTL and ADI, but when electronic first curtain is used, it does not seem to emit the usual pre-flash burst - only when you use the mechanical shutter. That makes me think that they are using the sensor itself, in this mode, to control exposure.

Gary Friedman is very adept at analysing how flash works on Alphas and has the necessary equipment, or access to it.

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by pakodominguez »

David Kilpatrick wrote:Minolta/Sony Pako, but actually, it's no more delayed than any other make. I tried both Pre-Flash TTL and ADI, but when electronic first curtain is used, it does not seem to emit the usual pre-flash burst - only when you use the mechanical shutter. That makes me think that they are using the sensor itself, in this mode, to control exposure.
Delay on flash photography (using Minolta/Sony) is not the biggest problem, but exposure is. I stop using TTL long time ago, and use only Manual settings. I haven't even invest on a 58 (I bought the 43 but now I'm selling it because I don't use it at all) I prefer to invest on sturdy 5400 (about 50$ on ebay for a good copy) and I can bounce the light everywhere, full power, and it keep working -not like the 43, that stop working as soon as it star "overheating"...
David Kilpatrick wrote: Gary Friedman is very adept at analysing how flash works on Alphas and has the necessary equipment, or access to it.

David
I hope we'll hear more from him soon ;-)
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Greg Beetham
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by Greg Beetham »

David Kilpatrick wrote:I don't have any problem understanding how that works. Radio triggers introduce latency through their use of digital processing, optical triggers like my Wein kit have zero latency and work at the speed of light. It's always a risk trying to sync studio flash at 1/250th; most units can not be reliably synced at that speed, and have much longer T=0.5 durations than their specs imply.

There is no such things as a simple X-synch left in any camera now. It's all microprocessor controlled, and the A99 is probably one of the more complex systems.

What matters is that is you shoot with electronic first curtain, you do not get a pre-burst, you get effectively instant exposure and you also get accurate exposure. That makes it the best camera for flash in the entire digital generation to date. The long shutter cycle all happens AFTER the exposure, except for the initial 1/60th which seems to be the handshake with the flashgun.

David
Ah ok radio trigger latency sounds good, what gave me pause was that radio also works at the speed of light but I guess there are radio triggers and there are radio triggers, I just naturally expected there would be almost zero lag in their design and execution, and why shouldn’t that be the case.
The Einstein studio flashes are supposed to be quite capable of sync at 1/250sec according to their specs, which they do when used with an oem flash and optical triggers. Understandably the photographer didn’t want the extra flash getting involved in the mix and so was trying to get the radio triggers working with most likely a higher than usual ratio of ambient light.
Anyway that seems to clarify the mystery.
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by David Kilpatrick »

Radio triggers have variable latency. For example, Elinchrom have replaced Skyport with Skyport Speed just to be able to ensure 1/250th sync. It's not the speed of radio waves, it is the speed of the CPU within the radio trigger. They are no longer simple analog devices.

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by Greg Beetham »

Ha ha yeah is this another example of replacing something simple that works with something complex that doesn't :lol:
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by Dusty »

Actually, if you look at the youtube video:http://www.youtube.com/watch?v=_SShHCsu ... ure=g-high, at around 8:45, he shows the viewfinder of both the a99 and D600, and comments that the Sony has longer viewfinder blackout then the Nikon.

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by bfitzgerald »

Dusty is robbing my information!
I found a great way to avoid any pre-flash and that's buy a Metz 58 AF-2 :mrgreen:
I've not really tried any of the radio triggers because for most of the stuff I do I simply don't see many situations where I don't have line of sight to the flashes.

But I would expect makers to start incorporating radio flashes more into their range (like Canon have)
I'd love to see Sony actually for once try to lead the way on this, they do need to overhaul the flash system to keep up. Minolta let things slip after they got a lead with wireless. A mount could have the best most advanced flash system around, but only if they work at it.
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by Greg Beetham »

You’re correct there Barry, Dusty found the same thing you did but it didn’t take long to recognize and take the necessary action.
The big problem with the Minolta/Sony IR sync is it can be stopped dead in its tracks by ambient light or even if the distance is greater than about 15ft, there isn’t any such problem with radio sync which is apparently the direction Canon has gone thus that system won’t have problems working flash fill in broad daylight. Some very nice photos can be had by underexposing ambient by a 1/3rd or even 2/3rd and leaving flash on full, it gets rid of unsightly bright sun highlights and fixes dark shadows under eyebrows and chins. (of course that is from my perspective here in the tropics, the sun might not be such a problem far in the north).
I have also seen comments elsewhere that in a more static environment (studio for example) with Nikon and Canon flash systems you can control the output of the flash-es from the camera position and that sounds very convenient.
There has been high speed shutter flash sync for a long time, the Dynax 9 had a sync speed of 1/300sec and the shutter went as high as 1/12000sec I think there are few cameras today with a focal plane shutter as good as that, by comparison the D4 has a 1/250sec sync and a top speed of 1/8000sec, and the 1DX is the same.
Light is measured in nanosecond (1/1000000000sec) increments, the controller chips and IC’s in the radio gizmo that arranges to send the sync signal at the correct moment have probably time to play a game of solitaire after the shutter button is pressed and the shutter organizes itself into a fully open position which closes the contact and sends the sync signal to the contact pin, I’d like to know how the designers have managed to screw that up, maybe it might be more to the point to ask ‘which designers screwed things up.’
I just think that it’s inexcusable to make something that works at close to the speed of light but then can’t react faster than a slow by comparison mechanical device…by a huge margin when you consider the operational envelope difference.
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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by Dr. Harout »

BTW, I've just read the following article here: http://www.photolife.com/blog/?p=11582

David, could you explain this: "Sharpness: Sharpness and resolution test results are only on an average level for a camera with a full-format sensor system. The A99 accomplishes a maximum of 3279 lines of nominal 4000 lines in picture height. This result is based on an intense sharpness filtering, which causes some overshot effects and halos on contour lines."?
A99 + a7rII + Sony, Zeiss, Minolta, Rokinon and M42 lenses

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by David Kilpatrick »

Basically it means the A99 is not very sharp. I'd agree. It's one step less sharp than the A900 at low ISO, and it doesn't take process sharpening very kindly - you tend to get a lot of noise and aliasing if you want to get maximum detail extraction.

I'm okay with it. It's not a very exciting camera except when I want to use ISO 1600 or faster, but it's more than good at 800 too. The D600 is better, but it does not focus as reliably.
anglescreen-85mm-100th6p3-640.jpg
anglescreen-85mm-100th6p3-640.jpg (90.77 KiB) Viewed 4342 times
Elderly expat man reading English language paper in southern Spain. Totally candid shot, using angle screen and the quiet operation (compared to D600 or A900) of the camera. 24-85mm at 85mm, at f/5.6, and ISO 640. This pic is pin-sharp and noise free at 100% view. But it would MORE pin-sharp on the D600 in theory. It would not be as good on a 900, or on an A77, as both would have quite strong noise by comparison.

The only way I can really begin to get a buzz out of the A99 is to work at ISO 50 and use extremely good lenses. My 24-85mm is not in that class but it's much better than a 13-year-old lens never designed for digital should be.

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Re: A99 shutter cycle - can owners pleae help me with a test

Unread post by pakodominguez »

So, the A99 is sharp but not sharper than the A900 unless you match it with digital optimized lenses?
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