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Thread: Af microadjustament calibration softwar

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    Default Af microadjustament calibration softwar

    Have anybody used the software of Reikan Tecnology (version 0,70 for Canon 7D) ?
    Thanks for notice about

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    Check out this site. http://www.northlight-images.co.uk/a...djustment.html I have used it on a 7D and 1D4 and find it is super. It is also free!

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    But also Reikan Tecnology is free and it is a software that verify the right AF!

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    Giovanni, it may work and from the comments on the site people seem to be relatively happy....but although they say it is fixed and that was in a previous version these lines makes me very nervous about trying this software:

    The previous release of this software (0.6.5) cause problems with some cameras which required a fairly convoluted reset procedure to be applied in order to get the camera to work again.
    and

    The result is – in my testing – the most reliable and solid version of the software to date (I say this with slight reservation as I’ve been a software engineer for long enough to know it doesn’t seem to matter how reliable the code is on one or 2 machines – when you put it out to the world, there are always crash reports etc back!)
    http://www.reikan.co.uk/photography/blog/?p=1541

    I'd personally rather use tried and true 100% problem-free methods that can only otherwise be spoiled by user error...
    Last edited by Daniel Cadieux; 11-21-2011 at 08:43 AM. Reason: added link

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    There is a really simple way to check microadjustment AF accuracy. No need for any software, or any setup. You can do it anywhere, anytime.

    Put your camera+lens on a tripod and aim at a flat static subject. The subject should be perpendicular to the sensor plane. Brick walls, very distant tree/house/building, or even the moon will work. You can even do this from a safari vehicle.

    Select single AF point (usually center AF).

    Focus as normal with the AF point on the subject.

    Turn on live view and zoom in all the way on the LCD on the area of the AF point.

    Half press shutter button and see if the focus changes.

    If focus changes, dial in some microadjustment and test again. In a few iterations, you'll get a feel for how much the adjustment moves the focus and you will converge on the best solution. All this will likely be faster than setting up an exotic test pattern that one purchases or using special software.

    I have noticed that with my 300 f/2.8 +2x TC on my 1DIV that I need a little microadjustment when the temperatures are warm, but not when cold. So it is best to test on site.

    Roger

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    Roger,
    I am just curious and not to hi jack this thread, but is this all you do for microadjustment or is this what you do for a quick field check?

    Dave

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    Quote Originally Posted by Dave Leroy View Post
    Roger,
    I am just curious and not to hi jack this thread, but is this all you do for microadjustment or is this what you do for a quick field check?

    Dave
    Dave,

    That is all I do. Fast, simple, accurate.

    Roger

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    Interesting. I'll try it out but I can't quite see why that works. I.e. why does the focus shift after switching into live view? I think of AF microadjustment as accounting for systematic error in the camera/lens combination. I can believe that it varies from day to day depending on atmospheric conditions, or at different focal lengths on a zoom, and so forth; but with all those factors held constant on a tripod, why does the focus shift when you're not correctly microadjusted?

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    Quote Originally Posted by Elliotte Rusty Harold View Post
    Interesting. I'll try it out but I can't quite see why that works. I.e. why does the focus shift after switching into live view? I think of AF microadjustment as accounting for systematic error in the camera/lens combination. I can believe that it varies from day to day depending on atmospheric conditions, or at different focal lengths on a zoom, and so forth; but with all those factors held constant on a tripod, why does the focus shift when you're not correctly microadjusted?

    Hi Elliotte,

    There is a difference because of the way the AF works. In the case of phase detect AF in a DSLR, there are separate sensors in the bottom of the camera and a mirror the deflects the light from the lens onto the AF sensors. The distance must be calibrated to on the order of 10 microns or better. The live view focus is on the sensor itself and works by contrast detection. So when you normally AF with the phase detect circuitry there can be an error in the calibration. The calibration can vary from lens to lens because of small differences in the bokeh as the phase detection is on an out of focus image from the lens. The contrast detection using the sensor in live view (which I call delayed view but that's another story) is optimised using contrast in the focused image on the sensor, a slower iterative process but for static subjects is very accurate.

    Phase detect AF is fast because, once accurately calibrated, a single reading tells the direction and by how much the lens needs to be moved to achieve focus. Contrast detect AF requires sensor readout, move the lens, sensor readout, analyze: did the contrast improve? Move the lens, read out sensor, etc, etc.

    Of all my lenses, I have only needed to microadjust my 300 f/4 and 300 f/2.8 with 2x TCs on the lens.

    Roger

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    Interesting. I had no idea that liveview actually used a completely different autofocus system.

    I tried setting up AF microadjustment with your system, and I confess I couldn't find any point where the focus didn't move. I didn't try every one of the 41 possible settings but at -20, +20, 0, 3, 6, 5, 8 and a few others it always seemed to move; and I couldn't see any difference to tell me in which direction I should be moving the AF microadjustment. It wasn't obvious to me how much the focus was shifting when I shifted into live view.

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    Quote Originally Posted by Elliotte Rusty Harold View Post
    Interesting. I had no idea that liveview actually used a completely different autofocus system.

    I tried setting up AF microadjustment with your system, and I confess I couldn't find any point where the focus didn't move. I didn't try every one of the 41 possible settings but at -20, +20, 0, 3, 6, 5, 8 and a few others it always seemed to move; and I couldn't see any difference to tell me in which direction I should be moving the AF microadjustment. It wasn't obvious to me how much the focus was shifting when I shifted into live view.
    Elliotte,
    I'm not sure what camera you are using, but do you have the custom function turned on the enables microadjustment? It is true that the method does not give you an idea which way to move the focus except by trial and error.

    Roger

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    Quote Originally Posted by Roger Clark View Post
    Elliotte,
    I'm not sure what camera you are using, but do you have the custom function turned on the enables microadjustment? It is true that the method does not give you an idea which way to move the focus except by trial and error.

    Roger
    I'm using a 7D, and yes; I had AF microadjustment turned on.

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    Elliotte,

    You say your tried "-20, +20, 0, 3, 6, 5, 8" and focus changed with each setting. If your lens was best at, say -5 or -10, then you would observe shifts with all the settings your tried. Probably best to try in positive/negative pairs to establish direction first. For example +5, -5, then +10, -10. Once you see an improvement in one direction, say -10, then try values around that point, e.g. -7 and -13 (which is better?). Let's say -13 was better than -5. Then test around the -10 and -13 values, e.g. --9, -12, -14 (which is best). It is not likely that one can tell much of a difference at this level with a 2x TC on, in which case any of those settings is close enough. With a sharp lens and no TCs, one might get finer.

    I generally start with +10 and -10 to see direction. Lets say +10 is better. I next try +5 and +15. and reduce range from there. I need to start keeping a log of what I find. I just tested my 300 f/2.8 on a 1DIV in the cold and found +10. I hadn't seen that before that I recall. It took less than 2 minutes. I do use a cable release most of the time if on a tripod.

    Roger
    Last edited by Roger Clark; 11-25-2011 at 01:42 PM.

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    Quote Originally Posted by Roger Clark View Post
    Elliotte,

    You say your tried "-20, +20, 0, 3, 6, 5, 8" and so focus change with each setting. If your lesn was best at, say -5 or -10, then you would observe shifts with all the settings your tried. Probably best to try in positive/negative pairs to establish direction first. For example +5, -5, then +10, -10. Once you see an improvement in one direction, say -10, then try values around that pount, e.g. -7 and -13 (which is better). Let's say -13 was better than -5. Then testaround the -10 and -13 values, e.g. --9, -12, -14 (which is best). It is not likely that one can tell much of a difference at this level with a 2x TC on), in which case any of those settings is close enough. With a sharp lens and no TCs, one might get finer.

    I generally start with +10 and -10 to see direction. Lets say +10 is better. I next try +5 and +15. and reduce range from there. I need to start keeping a log of what I find. I just tested my 300 f/2.8 on a 1DIV in the cold and found +10. I hadn't seen that before that I recall. It took less than 2 minutes. I do use a cable release most of the time if on a tripod.

    Roger
    A cable release is certainly a good idea. I really need to get me one of those. :-)

    However I couldn't really see any difference from -20 to +20 on the LCD. Possibly if I loaded the images onto a computer I might be able to see something, but right now the difference is just not significant enough when focusing on a wall to tell. Also possibly if I were focusing on one of the targets or Lenscal devices, focusing issues might be more obvious.

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    Quote Originally Posted by Elliotte Rusty Harold View Post
    However I couldn't really see any difference from -20 to +20 on the LCD.
    How about -10 and +10?

    What lens are you testing?

    Roger

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    Quote Originally Posted by Roger Clark View Post
    How about -10 and +10?

    What lens are you testing?

    Roger
    Also, do your testing wide open. When in live view, the lens should be wide open.

    Roger

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    Roger, is the goal with the method you describe to arrive at a setting that result little or no change when you half press the shutter? Cheers Mate,
    Cheers, Jay

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    Quote Originally Posted by Jay Gould View Post
    Roger, is the goal with the method you describe to arrive at a setting that result little or no change when you half press the shutter? Cheers Mate,
    Yes Jay.

    Roger

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    Roger,
    Thanks for this mini-class - right here on the BPN Network!

    I use a 7D with a 100-400 lens for most shots. Should I check both extremes of zoom? If so, do I need to modify how far away my target is? it seems that the moon is infinite (relatively speaking) versus a brick wall. How important is the distance in the whole equation?

    I remember using a Moray pattern on a computer screen to test mine. I did every step from -20 to +20 and it was still a little difficult to tell which produced the strongest interference - thus the optimal setting, so I am looking forward to checking this against your method - which sounds much easier. Plus I like the field check ability.

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    Quote Originally Posted by Cal Walters View Post
    Roger,
    Thanks for this mini-class - right here on the BPN Network!

    I use a 7D with a 100-400 lens for most shots. Should I check both extremes of zoom? If so, do I need to modify how far away my target is? it seems that the moon is infinite (relatively speaking) versus a brick wall. How important is the distance in the whole equation?
    I think the 7D only has one setting for each lens setup (bare lens, lens +1.4xTC, lens +2x TC), correct? Thus, I would suggest trying the calibration around the focal length you are using most.

    Regarding distance, the difference in focal position from infinity to 10 meters for a 400 mm lens is only: about 4 mm in the focal plane, which is not much, and whould not make much change in aberrations. As one focuses closer than about 10x the focal length of the lens, aberrations might change and affect microadjustment, but it will likely be a subtle effect. So it should not matter what distance one calibrates at unless one is imaging real close, in which case a calibration at that distance would be best.


    Quote Originally Posted by Cal Walters View Post
    I remember using a Moray pattern on a computer screen to test mine. I did every step from -20 to +20 and it was still a little difficult to tell which produced the strongest interference - thus the optimal setting, so I am looking forward to checking this against your method - which sounds much easier. Plus I like the field check ability.
    The Moire pattern is a very sensitive test, more so than my live view method. However, the fact that it is hard to find the best position from +20 to -20 indicates the focus in general is soft. This probably should not be surprising as the 100-400 is not a super sharp lens according to Canon's MTF data.
    But it will be interesting to hear your experience with the live view method as it might work better with the 100-400. The softness of the lens acts as a blur filter, reducing any moire effect. The live view method being slightly coarser may mean a clearer answer.

    I have written up the method in more detail:
    http://www.clarkvision.com/articles/microadjustment/

    Roger

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    Roger, you are an amazing sharing person. I will get to Colorado someday to shake your hand! Cheers Mate, Jay
    Cheers, Jay

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    Roger thanks for the input. I hope a final question as I went out and tried your method. When I switched to Live View mode the focus seemed sharp. When I went to push the shutter 1/2 way while on Live View (and zoomed in 10X) there was a significant sliding in and out of focus but it seemed to come back to the same place - and then it beeped. Is that focus shift what I should expect or should there be none and just a focus beep? If it always does that, should I be trying to determine the difference in focus before and after from memory?

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    Quote Originally Posted by Cal Walters View Post
    Roger thanks for the input. I hope a final question as I went out and tried your method. When I switched to Live View mode the focus seemed sharp. When I went to push the shutter 1/2 way while on Live View (and zoomed in 10X) there was a significant sliding in and out of focus but it seemed to come back to the same place - and then it beeped. Is that focus shift what I should expect or should there be none and just a focus beep? If it always does that, should I be trying to determine the difference in focus before and after from memory?
    Hi Cal,

    I have observed this too. In live view contrast AF, the camera must guess which direction to move to test. If it guesses wrong, or it is already at the best focus, then it moves the lens to a worse position and it analyzes that and moves back. In that condition, you have to remember what is was before to after it settles down and evaluate if the new live view focus position is better. I've also seen the case where there is no hunting and the first guess moves the focus to a better position very fast.

    So bottom line is study the image from the viewfinder AF on the magnified live view screen then half press the shutter and wait for it to settle down to the best focus. If what you remember from a second ago closely matches the new view, then you are close enough. If it is that close, I test 2 or 4 times.

    If the scene you are trying to test on has some depth, e.g. a tree, the different distances in view might cause the live view focus to jump around while it hunts (same with viewfinder AF). To minimize the hunting, a flat subject that is perpendicular to the field of view is best. This may not be easy in some field conditions. I have used trees, bushes and animals, none of which are flat. I just try and be careful and find the flattest section that the AF point fits within it.

    Roger

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    Roger:

    Do you feel that using the cameras LCD allows you to judge the focus as critically as you would be able to on your computer monitor? I have done it both ways with a Lens Align Pro, and I am able to discriminate more easily on the computer monitor.

    The other thing I like about the lens align method is that you can visually see which way your focus is off, and it speeds up the adjustment process.

    Even wide open there is a noticeable area of sharpness fore and aft of your focus point, and the lens align allows to see how that zone is distributed around your focus point.

    I do really like the idea of being able to test it in the field with your method, esp. after a rugged trip where the gear might get banged around a bit.

    Appreciate your thoughts!

    Cheers

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    Quote Originally Posted by Randy Stout View Post
    Roger:

    Do you feel that using the cameras LCD allows you to judge the focus as critically as you would be able to on your computer monitor? I have done it both ways with a Lens Align Pro, and I am able to discriminate more easily on the computer monitor.

    The other thing I like about the lens align method is that you can visually see which way your focus is off, and it speeds up the adjustment process.

    Even wide open there is a noticeable area of sharpness fore and aft of your focus point, and the lens align allows to see how that zone is distributed around your focus point.
    Hi Randy,

    I agree. A computer and an alignment method with a tool like Lens Align Pro is superior and more accurate. But over the last year I have found the same lens+camera varying in focus calibration depending on the environment. I see a difference between a hot and cold day, e.g. the Serengeti to Colorado.

    For example, you are at your favorite birding spot. Do you carry Lens Align Pro and computer to the site and calibrate there? How does one do it in a safari vehicle, or in a blind? The live view method allows one to do the calibration anywhere.

    Quote Originally Posted by Randy Stout View Post
    I do really like the idea of being able to test it in the field with your method, esp. after a rugged trip where the gear might get banged around a bit.

    Appreciate your thoughts!

    Cheers

    Randy
    If a camera+lens varies a little with temperature, then it seems like it would matter little how good the calibration was back home with the computer and Lens Align Pro. What matters is: is the calibration accurate for your imaging session in the field? So even if a live view test is less precise, it may ultimately be more accurate for that session.

    It seems that I've seen more variation in calibration with my 300 f/2.8 than with my 500 f/4, but that may be because I took the 300 out more this year than in previous years (I like the speed, both optically and the AF, and it is so light).

    I also would like to clarify what I mean by temperature variation. It is not the lens changing length, which does happen. The camera will compensate for that except in a long time exposure. Assuming normal photography of focus and shoot with exposures under a few seconds, the AF system compensates for lens changes with temperature. What matter is differential expansion within the camera body, where the path to the AF sensors can vary from the direct path to the sensor as a function of temperature.

    A separate issue is long exposure photography, or if you set the lens to manual. I do astrophotography and have had the focus drift off significantly with my 500 f/4 in twenty minutes with only a few degree temperature change. I remember one session of an hour doing 90 second exposures and after 20 minutes, the images were too out of focus to use. I had focused manually and turned off AF to do the exposures.

    Roger

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    Roger this is interesting about the differences in locations and climate. Do you recall if the setting you had at one location and temp was similar to when you visited again after having gone somewhere else in between where you had to change the AF MA?

    Also, I curious how much the setting varied? Just a few points or much larger swings?

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    Quote Originally Posted by Doug Schurman View Post
    Roger this is interesting about the differences in locations and climate. Do you recall if the setting you had at one location and temp was similar to when you visited again after having gone somewhere else in between where you had to change the AF MA?

    Also, I curious how much the setting varied? Just a few points or much larger swings?

    Hi Doug,
    I first noticed this issue while on safari in Tanzania last February. I noticed that in the warm Serengeti my 300 + 2x needed about +10 MA whereas when I checked it at home (Colorado) in the previous fall on the Moon (so cool evenings) MA was zero. When I returned home after the Serengeti, MA was back to zero on the moon in cool evenings. That is over about a 40 degree F temperature range.

    Roger

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    Roger:

    This is great stuff. I had never heard about such significant effects of temperature on the micro adjustment, and had always thought of it more as a method of compensating for manufacturing variances.

    The temperature issue (which makes sense of course) adds a new wrinkle to the equation. Perhaps I will do a controlled trial with the rig at different temperatures, record my results, and then just dial in the appropriate temperature compensation factor when in the field !!

    I often shoot in the winter in Michigan, which can get a bit nippy, so will have to look into this issue.

    Thanks!

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    Great discussion!
    One question: what type of Canon camera do you own? I understand that you can even adjust your camera to work with different lens and TC's stacked. Is this correct?

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    Quote Originally Posted by Juan Carlos Vindas View Post
    Great discussion!
    One question: what type of Canon camera do you own? I understand that you can even adjust your camera to work with different lens and TC's stacked. Is this correct?
    Hello Juan,

    I currently use a 5D Mark II and 1D Mark IV. The cameras will generally hold in memory settings for a number of lenses, each bare (no TC), with a 1.4x TC, and a 2x TC, but not stacked TCs. Also, I'm not sure some cameras will store data for a 2x TC when the f/ratio is f/8 or slower as the camera will not AF (e.g. all but the 1D series).

    Roger

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    Roger - how far away from the target would you be if you were testing a 600 lens with a 14 tc? I heard if you are too close focus at long distances will be off.

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    Quote Originally Posted by allanrube View Post
    Roger - how far away from the target would you be if you were testing a 600 lens with a 14 tc? I heard if you are too close focus at long distances will be off.
    I tend to select targets that are near the same distance as my subjects. When I've done that, I have still gotten excellent results for subjects at infinity (e.g. the Moon and stars). If you have different microadjustments versus distance, that is likely an indication of spherical aberration at close distances (which is possible on non-macro lenses).

    Roger

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    Hi Roger- Late to this thread, but I wanted to mention something. If you focus using phase-detection then turn on Live view and focus using contrast-detection, surely you will get some movement of the focus dial because of the way the contrast-detection system hunts for correct focus. As there are no precise reference marks on the focus dial of Canon lenses it would be impossible to tell if the focus point actually changed.

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    Quote Originally Posted by John Chardine View Post
    Hi Roger- Late to this thread, but I wanted to mention something. If you focus using phase-detection then turn on Live view and focus using contrast-detection, surely you will get some movement of the focus dial because of the way the contrast-detection system hunts for correct focus. As there are no precise reference marks on the focus dial of Canon lenses it would be impossible to tell if the focus point actually changed.
    Hi John,
    I agree that it would be tough to tell by lens markings. But a better way is to zoom in the max zoom and examine the image first with phase detect focus, then by live view. Did the live view focus get better?

    Roger

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