Specifically for the discussion of the A-mount DSLR range
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bfitzgerald wrote:I've never seen anything like it being honest. Unless he was shaking the tripod I can get 1:1 macros on a tatty tripod and MLU tack sharp.
BTW I have to point out our friend was the one who said the A550 didn't need MLU
I'm not buying this one sorry folks..
Sure your macro photos look sharp, but they might be sharper and showing more detail with a camera like the A77.
I compared the A550 to the A700 and A900 and from this I concluded that the A550 don't need MLU.
I used long focal lengths (400 to 800 mm) and the A550 images were as sharp as from the A700/A900 with MLU.
At around 1/60 sec the A550 showed neglible vibration, still way better than the A700/A900 without MLU and close to the MLU results.
Some test results were posted in the Sony SLR forum at Dpreview, so you can find them there.
I’m prepared to cop it on the chin; I can’t imagine Magnar would have any particular interest in fudging the tests. The thing that strikes me about magnification is when you compare high magnification of something up close and high magnification of something far away the most difficult too get under control is the distant one. The high magnification up close is difficult at the best of times but is mainly concerned with dof as a first priority, juggling shutter speeds and f-stops, though one can usually obtain a respectable result with macro if one employs a good percentage of motion freezing flash in the exposure mix despite the potential of detail loss from a number of different avenues.
When you compare high magnification macro to telephoto high magnification there is usually no way to employ motion freezing flash, also there is a difference between the two in angular displacement of the subject across the sensor from movements of any source at equal magnification, simply due to the large difference in distance.
I am assuming of course that a motion of amplitude x at a few inches with a subject and camera assembly is not going to be equal to the same motion of a subject and camera assembly if the distance becomes many metres given roughly the same magnification. Target shooters know about those phenomena very well, nothing degrades accuracy more than simply adding distance.
Greg
Greg Beetham wrote:I’m prepared to cop it on the chin; I can’t imagine Magnar would have any particular interest in fudging the tests. The thing that strikes me about magnification is when you compare high magnification of something up close and high magnification of something far away the most difficult too get under control is the distant one. The high magnification up close is difficult at the best of times but is mainly concerned with dof as a first priority, juggling shutter speeds and f-stops, though one can usually obtain a respectable result with macro if one employs a good percentage of motion freezing flash in the exposure mix despite the potential of detail loss from a number of different avenues.
When you compare high magnification macro to telephoto high magnification there is usually no way to employ motion freezing flash, also there is a difference between the two in angular displacement of the subject across the sensor from movements of any source at equal magnification, simply due to the large difference in distance.
I am assuming of course that a motion of amplitude x at a few inches with a subject and camera assembly is not going to be equal to the same motion of a subject and camera assembly if the distance becomes many metres given roughly the same magnification. Target shooters know about those phenomena very well, nothing degrades accuracy more than simply adding distance.
Greg
Well stated, and this point crossed my mind too.
You don't suppose Magnar could have been shaking the A700 tripod to get his result, do you?
edrice wrote: You don't suppose Magnar could have been shaking the A700 tripod to get his result, do you?
The goal of running my own tests is learn my cameras and lenses to know, so that I can get the most out of the gear.
If I find the results of general interest, I might post some examples and a text that explain the methods used.
They are all easy-to-be-repeated tests, so posting fake results would be really really stupid.
edrice wrote: You don't suppose Magnar could have been shaking the A700 tripod to get his result, do you?
The goal of running my own tests is learn my cameras and lenses to know, so that I can get the most out of the gear.
If I find the results of general interest, I might post some examples and a text that explain the methods used.
They are all easy-to-be-repeated tests, so posting fake results would be really really stupid.
I agree. That was my point. It wouldn't make any sense.
The degree of difference in motion blur between the A700 MLU and non MLU shots look plausible too me, I’d be astonished if you could fake that too that degree of exactitude. 1200mm equivalent is a lot of magnification so it’s not surprising that it would show ‘some’ induced blur from mechanical motion, at that kind of focal length I think you would have to bed the camera down in sandbags on a steel bench (like benchrest shooters do with their extremely accurate rifles) to minimise to the maximum any induced motion blur. The A77 with its electronic shutter seems to be achieving almost zero motion blur without doing that, very impressive.
I looked through my largish astronomical telescope one day downstairs (had to check and set collimation, I had never really played around with it before in daylight) and while I was there I tried the T adaptor for the A-mount just too see if I could reach prime focus with the sensor and get some kind of image. The short answer was no, I would have to re-jig the main mirror forward of its position so that could extend prime focus further out and that in turn would necessitate exchanging the secondary mirror with a larger one and messing up collimation….again.
So what I did was attempt some eyepiece projection into a short focus lens on the camera and that did work, boy did that work, I had the scope on the upper part of a telegraph pole down the street and through the 12mm Nagler eyepiece with the eye one could see the distant wooden pole and the rough grain of it three quarters across the field of view, then looking through with the camera added on at first I didn’t know what I was looking at, then I realized I was looking at a small knot in the wood, somewhere on the pole. At that magnification despite having a heavy solid mounting one light touch on the scope tube was enough to see lots of shimmers in the view, the amplitude was small but the frequency was high and damped quickly. That is the kind of motion blur that I would suspect a camera would record that has mechanical induced motion blur at high magnification, very difficult to control and get rid of entirely, the only real answer is too have as few moving parts as possible or not have any moving parts at all…ideally.
Greg
I'm not suggesting the tests are fudged, I am suggesting something is wrong. I've never seen mirror slap to that degree following "good practise"
Such as
MLU
Remote release
Tripod
There would have to be a significant vibration esp with a heavy tripod and lens to see a problem with the above being followed.
Whilst I don't own an A700 I am surprised that it's that severe. And just for the record I've never had mirror slap to that degree, nor any notable issues when using a macro/longer focal length. I could put the 5d on a budget Velbon right now with MLU and a 300mm lens and I'd def not get any mirror slap with MLU. Ditton D90 and the Tamron 90mm not sign of it so long as you use the Nikon ish MLU (1 sec delay)
Greg Beetham wrote: So what I did was attempt some eyepiece projection into a short focus lens on the camera and that did work, boy did that work, I had the scope on the upper part of a telegraph pole down the street and through the 12mm Nagler eyepiece with the eye one could see the distant wooden pole and the rough grain of it three quarters across the field of view, then looking through with the camera added on at first I didn’t know what I was looking at, then I realized I was looking at a small knot in the wood, somewhere on the pole. At that magnification despite having a heavy solid mounting one light touch on the scope tube was enough to see lots of shimmers in the view, the amplitude was small but the frequency was high and damped quickly. That is the kind of motion blur that I would suspect a camera would record that has mechanical induced motion blur at high magnification, very difficult to control and get rid of entirely, the only real answer is too have as few moving parts as possible or not have any moving parts at all…ideally.
Greg
Right! And a nice story!
Solid state is what we want! I am now using non compressed video for planet capture, and it works great.
Now I am looking forward to SLT cameras with electronic shutter -- or better, also with fast autofocus without the translucent mirror.
I'd love to see how they're going to do that one. I think DK mentioned one very obvious point, moving sensor with SSS, how are you going to put phase detect sensors into the main imaging sensor? It would seem Sony might have boxed themselves into a corner.
As for the A700 (you didn't make any further mention) I'd have offloaded that if the mirror slap is that bad, the camera isn't fit for purpose if 2 sec MLU won't provide sharp images tripod mounted.
Looking at the photo community as a whole and people I know, very few seem that interested in the SLT offerings (right or wrong) Sony have not really inflicted a knock out blow some predicted, it seems as if most folks could not care less for the EVF only approach.
bfitzgerald wrote: As for the A700 (you didn't make any further mention) I'd have offloaded that if the mirror slap is that bad, the camera isn't fit for purpose if 2 sec MLU won't provide sharp images tripod mounted.
When using very long focal lengths I have found mirror vibration to be a real world problem.
The worst camera I have owned in this respect was the Leica R3 SLR which was terrible even with 400 mm focal length lenses -- and no MLU.
The A700 seems to perform as bad or good as other cameras with a similar shutter mechanism.
So I am not surprised by the results (two tripods, remote, MLU, no wind, steady air with little turbulence, etc.)
Magnar Fjortoft wrote:
Solid state is what we want! I am now using non compressed video for planet capture, and it works great.
Now I am looking forward to SLT cameras with electronic shutter -- or better, also with fast autofocus without the translucent mirror.
Actually, I wonder why they didn't go with a leaf shutter in mirrorless models. Leica even put them in it's S2 line-up, albeit as additional shutters in the lenses. They could have incorporated them into the body as the old TLR cameras did.
You then can get flash sync at any speed!
Dusty
An a700, an a550 and couple of a580s, plus even more lenses (Zeiss included!).
Dusty wrote:[ctually, I wonder why they didn't go with a leaf shutter in mirrorless models. Leica even put them in it's S2 line-up, albeit as additional shutters in the lenses. They could have incorporated them into the body as the old TLR cameras did.
You then can get flash sync at any speed!
Dusty
I've always wondered what leaf shutters can do to an image bokehwise. Last time I shot with one was my Hi-Matic-9 back in the 60s. Wouldn't you have a changing DOF as the shutter opens up and then closes again? What you're focused on doesn't really matter but what is the effect in foreground and background for areas that would normally be out of focus with this variable DOF?
