Luminous Landscape Forum
Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: ErikKaffehr on November 20, 2011, 11:24:34 am
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Hi,
I made a small experiment with MLU and without MLU. I made a series of exposures with and without mirror lock up and measured resolution using Imatest. Some screen dumps re included. The Imatest results are calculated for a vertical structure and a weighted average for two structures, one horisontal and one vertical. As expected the vertical structure shows the largest change.
The images are about worst case f/8 at 1/10s.
Other parameters:
- The camera was a Sony Alpha 900
-Camera focused on AF (as I got worse results using MF).
-Release from computer with USB cable
-Gitzo GT3541LS tripod without center column, Arca Swiss D4 head. Minolta 80-200/2.8 APO at 200 mm.
An RRS Macro Focusing Rail was on the head, this may have affected stability somewhat negatively.
My conclusion is that MLU is worthwhile, but your mileage may of course vary, depending on camera an tripod.
Best regards
Erik
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Nice work, Erik. The differences are clearly visible and are quantified by Imatest, and are larger than I would think even for a 200 mm lens.
Regards,
Bill
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Camera Model?
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Hi,
Sorry, Sony Alpha 900. Updated original posting with info on camera model.
BR
Erik
Camera Model?
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My conclusion is that MLU is worthwhile, but your mileage may of course vary, depending on camera an tripod.
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Your results mimic my findings. I thought that with a heavy tripod an a good ball-head, nothing would be gained with MLU but I was dead wrong!
Anyway, thanks for sharing you experiment!
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Thanks for sharing. Yes, similar experience to mine. 1/15 to 1/4 sec tends to be the tough spot for mirror vibration. This is why for macro & landscape work, I now prefer to shoot in Live View mode with electronic first curtain: nothing moves prior to exposure except possibly the aperture blades. (I can also verify using the high 10x magnification mode that there isn't any external vibration -- e.g., wind -- affecting the image. That is, if I see the image bouncing around on the LCD screen, probably not a great time to take the picture ... unless I want that effect! :) )
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Eric,
Does the A900 have Image Stabilization?
If so, would be interesting to repeat
With new OLED technology pentaprism/mirrors will go the way of the dodo eventually, with a few exceptions...
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Hi,
Yes, the A900 has image stabilization but my experience is that it is no-no when the camera is on tripod, it should only be used when needed. That is my practical experience.
I'm a firm believer in mirrorless. I have a Sony Alpha 55 SLT (with transparent mirror) and that camera is essentially vibration free.
Best regards
Erik
Eric,
Does the A900 have Image Stabilization?
If so, would be interesting to repeat
With new OLED technology pentaprism/mirrors will go the way of the dodo eventually, with a few exceptions...
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Hi,
Yes, the A900 has image stabilization but my experience is that it is no-no when the camera is on tripod, it should only be used when needed. That is my practical experience.
I'm a firm believer in mirrorless. I have a Sony Alpha 55 SLT (with transparent mirror) and that camera is essentially vibration free.
Best regards
Erik
My A77 is spooky good with both pellicle and IS as well as no first curtain!
Why would IS be a no-no on tripod, I don't understand?
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Hi,
It seems that the shake sensor can produce fake signals so the camera moves the sensor to compensate. It has ruined a lot of pictures for me.
I enclose two screen dumps at 1:1 and 2:1 (for easier viewing). Exposure data: MLU, 50 mm, f/8 and 1/160 s.
The problem is not very obvious in this case, but it does degrade the image.
Best regards
Erik
My A77 is spooky good with both pellicle and IS as well as no first curtain!
Why would IS be a no-no on tripod, I don't understand?
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Hi Erik
Thanks for sharing. As mentioned before I have had contrary results, but my tests were quite amateurish. It is a surprise to me that this is a tool that many professionals want on their camera, yet there's no conclusive evidence of its utility under all circumstances. It's no wonder DSLR manufacturers have used the system (SLR) in the digital age - it's a very good system.
If anybody is interested, my amateurish test and results are here: http://sareesh.com/2011/10/how-important-is-mirror-lockup-and-a-cable-release/
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If you have a light camera with a small mirror (i e APS-C) and poor resolving power in the lens and a stable tripod (expensive carbon tripod) mirror slap will probably not disturb much. Shutter speed is also a factor. I guess that mirror moving speed can vary too, that it is an advantage to have a low fps camera.
Where the line between when you get problems and when you not get them is hard to find (which lenses shutter speed combinations etc). I prefer using a safe technique all the time when I do high res still life to minimize vibration risk. What I have learnt so far from vibration is that you need some overkill, a bit more stable tripod than you think etc. When I shoot high res still life I use live view mode for focusing, and then mirror up comes "for free".
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Hi,
I'm not really sure that the carbon fibre helps. It's very stiff but also lightweight. The present experiment was done using one of the better CF tripods around, the Gitzo GT3541LS with just three leg sections extended and Arca + RRS stuff on top. The test was done at 200 mm. Angular motion would be much less with shorter lenses.
Best regards
Erik
If you have a light camera with a small mirror (i e APS-C) and poor resolving power in the lens and a stable tripod (expensive carbon tripod) mirror slap will probably not disturb much. Shutter speed is also a factor. I guess that mirror moving speed can vary too, that it is an advantage to have a low fps camera.
Where the line between when you get problems and when you not get them is hard to find (which lenses shutter speed combinations etc). I prefer using a safe technique all the time when I do high res still life to minimize vibration risk. What I have learnt so far from vibration is that you need some overkill, a bit more stable tripod than you think etc. When I shoot high res still life I use live view mode for focusing, and then mirror up comes "for free".
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I would say that a stable tripod helps, but does not necessarily solve the problem. I recently upgraded to a Systematic Gitzo tripod, but still use mirror lockup.
Good point about the tele lens, forgot to mention that. It is a huge difference in angular resolution between say 24mm and 200mm, and thus the 200mm lens is much more sensitive to vibrations. An interesting experiment is to zoom in live view 10x and tap on top of the camera and see how long it takes before the vibration stops (which is clearly visible as movement in 10x zoom).
Using mirror up my experience is that it is possible to make sharp images also with a quite unstable tripod, electronic shutter may also be part of it. However, in windy conditions images won't be max sharp, and long exposures rarely becomes max sharp either with a weak tripod. A stable tripod can really improve the results there.
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I will echo Erik's statement about CF tripods - I'm really not too sure about its utility against heavier tripods - or maybe I'm spoilt coming from the video world. I've used light Gitzo CF, and I found them almost 'toy-like'.
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I will echo Erik's statement about CF tripods - I'm really not too sure about its utility against heavier tripods - or maybe I'm spoilt coming from the video world. I've used light Gitzo CF, and I found them almost 'toy-like'.
Ahh... you meant if carbon is better than say a heavy aluminum tripod? Stability is certainly the main factor, an alu tripod that can support 40 kgs is certainly better than a carbon that can support 18 kg. However, a carbon tripod can be made lighter than an alu tripod with the same stability, that is the advantage for us that carry the equipment out in the landscape.
I've heard that carbon legs have better properties concerning damping vibrations introduced from the ground or the wind compared to aluminium, but I don't know if that is true, perhaps there is a little difference. I would guess that wood could be better than aluminium in the same way, but then we get really heavy tripods. My reason for using carbon is being able to have an "overkill" stability without carrying too much weight.
I use a Gitzo GT3541XLS Systematic (max load 18 kg, my equipment weighs 3 - 4 kgs). It has a max height of 6.6' (198 cm) despite having no center column so often I use only two of the four leg sections, and sometimes do overhead shots, it only weighs 2 kgs (4.3 lbs). I think one should go for the more robust carbon tripods, the smaller lighter Gitzos are indeed a bit toy-like. The drawback of this tripod is that it kind of sucks for macro shoots near ground level, but I can manage.
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Thanks to Erik for making this test. My A900 is always set for mirror lock-up, which is sometimes annoying for the occasional handheld grab shot. It is important to be patient between sending the mirror up and actually releasing the shutter -- waiting 10 seconds is probably a minimum. Regarding the in-camera stabilization, I too have ruined a number of images by leaving it on unintentionally. Nevertheless, when there has been some wind or other vibrations affecting the tripod and adequate time for several exposures, I have tried to shoot with and without the stabilization. After the fact, particularly months later, I'm unsure whether the SSS made a positive difference or not. Anyone know if stabilization on/off is recorded in the A900's EXIF data?
Regards,
Rick
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Hi,
Yes, it is recorded but not visible in lightroom. I can see it in Sonys raw converter.
Best regards
Erik
Thanks to Erik for making this test. My A900 is always set for mirror lock-up, which is sometimes annoying for the occasional handheld grab shot. It is important to be patient between sending the mirror up and actually releasing the shutter -- waiting 10 seconds is probably a minimum. Regarding the in-camera stabilization, I too have ruined a number of images by leaving it on unintentionally. Nevertheless, when there has been some wind or other vibrations affecting the tripod and adequate time for several exposures, I have tried to shoot with and without the stabilization. After the fact, particularly months later, I'm unsure whether the SSS made a positive difference or not. Anyone know if stabilization on/off is recorded in the A900's EXIF data?
Regards,
Rick
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Erik: Thanks for suggesting Sony's software for checking on the stabilization. There are a few series that I've always been curious as to whether the pick of the bunch was with the SSS on or off. Much appreciated.
Regards, Rick