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Mike Kobal

December 6, 2011

AF in manual video movie mode workaround Sony SLT A77

Filed under: Gear Reviews — mike.kobal @ 8:18 pm


I couldn’t hide my disappointment when I learned AF only works in P mode with the A77. Bummer, who wants to shoot in P mode with a camera like this! Manual controls is where its at and 90% of the time I prefer manual focus. But then there are situations when AF would be nice, even necessary to get the shot. After playing around in P mode and realizing auto focus on the A77 is almost as good as on the Sony FS100 I had to find a work around. It is too good not to be used!
There are a few ways getting around this annoying limitation, let’s start with the lazy version.

Put the camera in movie mode and Auto ISO, program mode will keep the lens wide open (necessary to achieve good AF, the reason Sony disabled manual shutter/aperture control), on the 16-50mm kit lens, it usually sets at f3.5 (at the time of this writing this is the only standard lens worthwhile using in AF mode) and adjusts the shutter speed accordingly. Setting it on Auto ISO is very convenient, since we cannot control the aperture, the two variables left are shutter speed and ISO settings and the program will always try to get close to the ideal shutter speed for your frame rate (and never below your frame rate, i.e. 60p, lowest shutter speed 1/60, 30p, lowest shutter speed 1/30), resulting in very low ISO values (Auto ISO in movie mode 100-1600).
Most of the time the camera picks 1/60 and 3.5 for 1080/60p and you can just hit the AE lock button and be done with it.
But what if you want to shoot at 1/125, you will have to trick the camera, use your Vari filter and point your camera at light or dark objects to obtain the desired shutter speed, then press the AE lock button and you are ready to roll.
If you choose to use higher shutter speeds, let’s say 1/400, its best to select a higher ISO value and watch the program setting, once you see the desired shutter speed appear, press the AE lock button. (If you would like to shoot at a shutter speed lower then your frame rate, manual mode is your only option)
A Vari filter is a must since this will be the only way to control exposure.
Most of them offer a 2 to 8 stop adjustment range which is plenty for most, even very challenging lighting situations.
If you find this information helpful, please consider helping me maintaining this blog by purchasing your gear through my product links to B&H. It will cost you nothing and allows me to keep adding! Or consider making a direct donation using PayPal


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20 Comments »

  1. [...] in manual video movie mode workaround Sony SLT A77 (Mikekobal). And contact sheets with A77 and NEX-5n [...]

    Pingback by sonyalpharumors | Blog | Sony A77 news and reviews roundup... — December 11, 2011 @ 5:00 pm

  2. Hi Mike,

    Thank you for that very interesting revelation you’ve shown us on pushing the video of the A77 to its full potential.

    I just want to know if it does work also on Sony A65 with the 18-55 kit lens? Why i’m asking this, because i’m planning to buy the A65 this week.

    Comment by Owen — December 18, 2011 @ 1:58 am

  3. Hi Owen, I am on location and don’t have the A65 here, I think it doesn’t have an AElock but will check when back end of the month, not sure how to work around w/o aelock

    Comment by mike.kobal — December 19, 2011 @ 2:02 am

  4. Thank’s Mike,

    There is an AEL button beside the video button.

    Hope it will work on the A65, so we could use the full potential of the kick ass phase dection AF.

    Comment by Owen — December 19, 2011 @ 10:55 am

  5. Hey Owen, yeah, that’s great news, should work!

    Comment by mike.kobal — December 22, 2011 @ 6:40 am

  6. Thank your very much Mike for your effort to help not just me also but some other dslt users.
    Just did purchase my A65 last Tuesday. And it was awesome!!!!
    Probably by next week before the year end i’ill buy my ND filter. hope i’ll get it right…
    Thank you again Mike for sharing your discovery. Now lets kick some phase detection AF.
    Merry Christmas Mike and God Bless….

    Comment by Owen — December 24, 2011 @ 1:53 am

  7. okay i have been doing music videos locally for some of my friends, since i dont have enough money i shoot on a canon hv30 and edit on corel pro x4, now i need to start getting better with quality i was going to get the canon xa10 someone says it suck with low light sensor, and suggest 5d mark II but other people says the 7d is better for video, can anyone really come honest which camera is better for music video, and how or what lenses to use to get great night shots? thanks in advance

    Comment by snake — December 29, 2011 @ 5:56 pm

  8. Mike,
    Just wanted to order a vari ND filter from B&H and since I was going to use them anyway, I figured I’d use your equipment link. Just to be sure, as long as I use the product link from your website, you’ll get the credit for the purchase correct? If not, what do I need to do in order for you to get the credit?

    Oh, keep up the good work on this forum…you’re one of the few pros that have provided great feedback on the A77 when it seems like all the Canon/Nikon “pros” won’t give Sony the time of day. I am *really* enjoying my A77 and my NEX-5N (especially for video) and I’ve learned a lot by watching the content on your blog.

    R/
    Dustin

    Comment by D Pierson — April 8, 2012 @ 6:18 am

  9. Dustin, glad to hear you are enjoying your 5n and A77, those cameras are ahead of the game and I can’t wait for the FF SLT Sony has in the works, if it performs as well as the A77 it will most likely become my main workhorse. Regarding BH, it is very easy, you can use a direct link or the BH link at the very end of the blog entry to click though to bh, then search for the product you need, and check out. Thanks much in advance and enjoy your cameras!
    Mike

    Comment by mike.kobal — April 8, 2012 @ 9:48 am

  10. MIke,
    Just to let you know that I finally got a moment to try out the AF video w/ vari-filter and it works beautifully even in the full tropical sun! I had no issues with the ND VF not being able to compensate for a very sunny day and in fact anything much more than 2 positions from neutral was under-exposing the video (okay, it was later afternoon but still very bright out). I still like to pull focus for different effects, but having the option to make the camera do the work is the best of both worlds. Thanks again!

    R/
    D

    Comment by D Pierson — May 6, 2012 @ 2:36 am

  11. Hi:
    I bought the A77 three months ago and just now started considering it for video work. Your video shooting workaround is so clever. Thank you. I will try it out shortly.

    Comment by Joe Friedman — September 21, 2012 @ 10:26 am

  12. How does this “trick” allow for AF in anything but P mode? All it appears to do is allow me to lock the shutter speed with AE lock.

    What mode are you using to get AF in anything but P mode for video? When you switch the camera to the movie mode dial, you get P, A, S, M. Only “P” allows AF. If this is a trick to lock exposure in P mode, then that’s fine, but it’s certainly not allowing me to use my lens wide open.

    Comment by Shawn — September 21, 2012 @ 4:23 pm

  13. that’s exactly what this is, tricking the camera into the desired shutter speed by using AE lock AND then using the ND vari filter to get the correct exposure.

    Comment by mike.kobal — September 21, 2012 @ 4:39 pm

  14. Hi Mike; enjoy your site. You realize the title and Youtube reads “AF in manual video movie mode workaround Sony SLT A77″

    AF in manual video movie mode.

    Comment by Shawn — September 21, 2012 @ 5:55 pm

  15. Just checked it out again.

    This should be “Fixed shutter speed in P mode workaround” not “AF in Manual mode” workaround.

    You have 4 modes with the a77 on the video dial

    P mode = Autofocus works, but the shutter varies and the aperture is fixed to F/3.5. You can, without using an ND filter (just point the camera at light or towards the sun) and get the shutter to 1/125 and hit the AEL button and that will set the shutter.

    A mode = Autofocus does not work (ever) and you set the F/stop to your preference. ISO can be set to AUTO or whatever you want. Shutter will fluctuate depending on the light. The AEL lock trick works in this mode as well, but you certainly don’t need an ND filter – just point it at the light or slightly towards the sun. Shutter will go from 1/60 to 1/8000 (USA model).

    S mode = Autofocus does not work (ever) and you set the shutter to your preference. The camera will adjust the ISO auto or manually, and the F/stop will go from fully open to F/16 (or F/22) depending on how far your lens will step down. So say you want F/9 with a 1/125 shutter, just point it near a bright source like the sun or light and hit the AEL lock button. Of note – this is before you hit the record button. Once you hit the record button, this camera will not “auto ramp” up or down the shutter like a GH2 will. So in video shutter priority mode, this is almost like effectively hitting “AEL” the same moment you press record. Try it; you’ll see what I mean. Again, no ND filter needed; just a 60 watt light bulb or that huge orange/red thing in the sky.

    M mode – Autofocus does not work (ever) and you manually set the ISO, F/stop, and shutter speed. One would not need to hit AEL lock in this mode as you have full control over everything already. No ND filter, and it will *not* ever AF in this mode.

    So, with the title saying “AF in manual video movie mode workaround” it doesn’t make any sense. Perhaps you meant “Shutter speed lock in P mode workaround”? It’s really just as simple as pointing it at a light or away from a light.

    Thanks,
    Shawn

    Comment by Shawn — September 21, 2012 @ 6:29 pm

  16. Just tested the whole shebang a 3rd time. Set it to video, P mode, point it at a light. Set your AEL button to “AEL toggle” in the camera menu so you don’t have to hold it down.
    Point it at a light; when it gets to 1/125 hit AEL. Poof, 1/125 shutter set.

    Why do I need an ND filter again? I have a really nice Singh-Ray thin vari-ND but I do not need it for this exercise.

    :)

    Happy shooting!
    Shawn

    Comment by Shawn — September 21, 2012 @ 6:35 pm

  17. The camera selects the aperture value at 3.5, assuming you have set manual ISO, the vari-ND filter is now your only way to get the correct exposure once you point your camera at your subject and to compensate for light changes during filming. So now you are shooting totally manual :) if you leave it on auto iso, you don’t need the vari filter but you also loose full control over exposure.

    Comment by mike.kobal — September 22, 2012 @ 6:57 am

  18. Hi Shawn, agree, the title is confusing and leaves room for interpretation, however, the vari filter is what turns it into “manual mode” you choose the shutter speed by tricking the camera with bright or low light to get to the desired value, you Iso is set manually, and the aperture is fixed at 3.5. You make full manual exposure adjustments with your vari filter.

    Comment by mike.kobal — September 22, 2012 @ 7:04 am

  19. Today i resolved Sony autofocus problem in video mode with open apertures: http://www.portreti.lv/how-to-hack-sony-alpha-99-65-77-to-work-with-open-aperture-in-video-mode-autofocus/

    Comment by Jurka — November 8, 2012 @ 4:03 pm

  20. very cool, thanks for the link, Jurka!

    Comment by mike.kobal — November 10, 2012 @ 8:55 am

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