Remote focusing question

I recently rented the Canon 400mm f5.6 to see if I like the lens before making the decision to purchase. I had the chance to photograph bald eagles from a very great distance (about 650 feet). I put my 2x TC on the lens which means the best F-stop I could get was f-11.
I mounted it to my tripod using a remote shutter release on my 7D II. The lens will only manually focus with a 2x TC mounted. I put the camera into Live View and set it to maximum magnification.
Now comes the tricky part. Trying to manually focus is not easy. Reason being that just touching the camera or any part of the lens causes the Live view to vibrate fairly hard and makes manual focus a tricky situation.

Now my question. Can you remotely adjust focus with some kind of app in my smart phone tethered to the camera? This way I could make the adjustments without touching the camera or lens. Does the 7D II have that capability and is there such an app?

By the way, here is the picture I got manually focusing the lens & TC combo making it 800mm, f-11, 1/60, 200 ISO:

IMAGE LINK: https://flic.kr/p/AGud​W7

If you are on a tripod, and using LV anyway, then the camera WILL AF with the 2× converter. The AF aperture restriction only applies when using the Phase Detect AF system through the Optical Viewfinder. In LV the camera uses the much slower, but more accurate contrast detect AF system that is only limited by needing sufficient contrast to measure. There is also an LV Quick AF mode, that flips up the mirror and uses PDAF, this of course won't work. The main issue with CDAF is it is so slow, especially with long slow lenses that it can be difficult to achieve focus lock on a quickly moving subject. Saying that using LV for action is not really that good, as the system as a very long lag time between pressing the shutter button, and actually recording the shot, so the slow AF is less of a drawback as the whole system is slower.

So on the tripod with a stationary subject I would consider using LV plus CDAF, if I had a moving subject then I would just use the normal optical VF and manually focus. The 7D has a pretty bright VF so you should be able to get away with using it to manually focus at f/11. I certainly never had any problems with MF on my old 300D with a 500mm f/8 mirror lens or when I tried a 75-300 with a 2× converter. But I did shoot film for many years with only slow old MF telephoto lenses, again at max apertures of around f/11, although of course on 35mm film.

Alan

If you have an Android phone, you could use DSLR Controller with an (most recent Android phones, 4.2 or later will support this) On The Go cable to allow USB connection to the camera to focus remotely. This is about a $10 app in the Google App Store. Or for free, there's QDslrDashboard, which runs on Android, Windows, Mac or iOS. Both can also be used wirelessly with a DSLR with WiFi, or by loading a new firmware onto a TP Link MR-3040 router (under $40).

Thanks Jon,
Just to be sure, you are saying that the $10 app DSLR Controller will let me adjust the Manual (or even auto) focus from an app on my smart phone tethered to the camera?
That would be perfect, especially as I have pretty much make up my mind to buy this very nice lens.

Yep. I use it all the time in AF mode with my 5D2 and Tamron 90 macro via the MR-3040 I mentioned.

To clarify, I can't see how a remote app would be able to manually focus the 400 5.6, only autofocus.

It allows you to incrementally turn the focusing motor until what you see (at 1x, 5x or 10x magnification) on the display is what you, not the camera's internal algorithm, call sharp.

That is great. I will look into getting one.
Thank you Jon.

hmm...and you can use that portable router if you want to shoot video with cameras that already have wifi...i may have to add it to my xmas list..

I haven't tried it with video; BTW, I note that as of Saturday (version 0.3.3), qDslrDashboard is now on the Google Play and Apple stores as a paid app, it always was pay on iTunes, but now it costs on Android too.

I've used DSLR Controller in the field for a few years, both tethered and wireless, and have nothing but good things to say about it.

F/11 at a distance of 400ft. How good is your image if you select infinity focus and then switch to manual focus? I'm not used to these super long focal lengths, but I'd imagine your DOF is big enough.

DoughnutPhoto wrote in post #17804597
F/11 at a distance of 400ft. How good is your image if you select infinity focus and then switch to manual focus? I'm not used to these super long focal lengths, but I'd imagine your DOF is big enough.

Selecting infinity focus is not particularly easy with a modern AF lens. To allow for the AF motor to not come to a jarring halt, the stop is somewhat past the point for infinity focus. So you can't just wind the lens around until you reach the stop, which you could do on many older MF lenses. IIRC there isn't actually a definitive marking on the not very useful distance scale for infinity either, just the symbol.

Alan

I was thinking point it at a nice cloud, autofocus and then select manual focus.

guntoter wrote in post #17800599
The lens will only manually focus with a 2x TC mounted. I put the camera into Live View and set it to maximum magnification.
Now comes the tricky part. Trying to manually focus is not easy. Reason being that just touching the camera or any part of the lens causes the Live view to vibrate fairly hard and makes manual focus a tricky situation.

I, too, have found Live View focusing to be completely useless with long focal lengths, for the exact reason you describe.
The mirrorless fanboys and people who say that EVFs are great obviously don't shoot at 600mm, 800mm, or 1200mm.