Nailing (auto-)focus with the Panasonic 100-300?

How can I _reliably_ nail auto-focus with the Panasonic 100-300 or with any other long lens, on an Olympus E-PL7?

Take, for instance, the first photo below. The camera was configured for S-AF. The focus area is constrained to the middle of the sensor area. And the Olympus EXIF indicates that the camera set the focus point splat on the shoulder of that gentleman (Danny McAskill of Youtube fame, in case you care).

The ORF original's EXIF claims a depth of field of 5.65 - 6.36m (focus distance: 5.98m).

So ... what can I do to get focus in these cases?

My challenges are:

1) I am unable to verify focus in the (large, bright!) VF-4 electronic viewfinder; even the dpreview inline rendition of the photo will appear sharp, while the 100% rendition will tell the sad truth

2) The Panasonic 100-300 focus ring is not exactly helpful for me; this removes the S-AF + M option and also the pure manual focus option (which I would me happy to use!). Auto-magnification otherwise could be a pleasure to use

3) smaller aperture, for increased depth-of-field - well, yes, but then we get into higher ISO and the low light (not in this very specific case, granted), and the Panasonic 100-300 seems to positively hate small apertures

Just to demonstrate that the lens and camera are capable, I put in a second shot taken at 300/5.6 (a combination which people here claim as being totally non-workable). That makes it a depth-of-field of about 40cm at about 15m distance. Reproducing that or better, consistently, from an auto-focus point of view, that's what I would like to figure out.

Both shots are straight from ORF raw via Olympus Viewer 3.

If at all possible, please avoid telling me that the answer is the Panasonic 100-400 (at three times the cost of the 100-300).

Out of focus(?) at 100/6.7; 1/750

In focus at 300/5.6; 1/1000

I don't think I've had much better results than that at 300mm f/5.6 with my GX7. The lens is just garbage at the long end in my opinion, certainly worse than my old Tamron 70-300mm on APS-C.

I haven't had a big problem with AF though, beyond the usual issues with tracking moving subjects using a contrast detect AF system. Does your 100-300 lock on accurately when aimed at a still subject?

Try putting it on a tripod, aim it at a well lit page of text, see if that's reliably focused upon.

Not familiar with that combination, but you could try a smaller AF-point and focussing twice before firing the shutter (i.e. half-press till focus confirmed, half-press again, press).

It looks to me that both images are just soft, not out of focus. My P100-300 is sharpest at 286mm, but goes a bit soft after that. Also, I shoot it at f6.3, if I can.

If you are using the IBIS on the PL7, try using the OIS on the lens, it is almost as good as the 5 Axis on my E-M5 II, and most likely better than the IBIS on the PL7.

P100-300 on E-M5 II, focus point on bird in nest.

If you camera has a pinpoint focus point and touch screen you can typically touch the screen where you want focus and/or release the shutter by touch screen.

Additionally a more narrow aperature f8 or f11 usually does the trick, but 300mm is REALLY long. F7.1 is as far as you typically want to go to get good crisp images.

You may want to get as close as possible to reduce the focal length, so you have a wider DOF. The longer the focal length, the shallower the DOF.

At f7.1 its only 7' at 250mm at 100' and 10' at f11, so you really need to focus on a fixed point and wait for your subject to hit that point and fire off a burst with the mechanical shutter. Unfortunately, you want to be at at 1/400 or faster which can be a stretch at that aperature (pray for a sunny day).

Find a DOF calculator (photo tools app) and get familiar with the in focus ranges. As well as hyperfocals.

What I've read tells me that the 100-300, the 100-400, and the Oly. 75-300 can all have difficulty nailing focus with targets that aren't close to the lens. Not everyone's experience by any means, but also not necessarily user error. I have a lot of trouble nailing focus with my 75-300. Give it a very contrasty subject like paper full of text - or a reasonably contrasty target only a few feet away - and S-AF mode seems to nail focus easily enough. Otherwise, what works best for me is using MF assists like focus peaking and zoom after a half-press of the shutter with S-AF. Since you don't consider that an option, I suggest trying the touch-screen as Spectre38 said - or try a continuous AF mode to see if that helps. I find with my Olympus cameras and the long tele that C-AF can be more reliable than S-AF. It's not consistent, though.

You can play with aperture, face-detect settings, and focus box size, too. These have not made a difference for me personally, but YMMV. Good luck!

I think the first shot focused on the parts nearest the camera, the forearm and the left hand. The lens can produce good results but it's not in the same league as Nikon or Canon pro lenses. I find I get good results if I shoot just short of 300mm and keep the shutter speed up. The lens wil hunt in continuous focus so BIF are most difficult. But good shots can be had. For the size of the lens it's an amazing focal length.

Egregius V wrote:

What I've read tells me that the 100-300, the 100-400, and the Oly. 75-300 can all have difficulty nailing focus with targets that aren't close to the lens. Not everyone's experience by any means, but also not necessarily user error. I have a lot of trouble nailing focus with my 75-300. Give it a very contrasty subject like paper full of text - or a reasonably contrasty target only a few feet away - and S-AF mode seems to nail focus easily enough. Otherwise, what works best for me is using MF assists like focus peaking and zoom after a half-press of the shutter with S-AF. Since you don't consider that an option, I suggest trying the touch-screen as Spectre38 said - or try a continuous AF mode to see if that helps. I find with my Olympus cameras and the long tele that C-AF can be more reliable than S-AF. It's not consistent, though.

You can play with aperture, face-detect settings, and focus box size, too. These have not made a difference for me personally, but YMMV. Good luck!

Don't put the Pana 100-400 in your list!

Have now shot over the 3000 long range shots and every time the focus was nailed, so fast that focussing and taking the shot just in the time by pressing the shutter.

Even little birds just with the head out of  the grass, I got direct in focus.

I understand your frustration and am beginning to wonder if this is where M43 cameras fail badly?

The computed DOF of the 100/6.7 shot should have been 90cm (online calculator and EXIF data agree). _If_ focus as claimed by the camera had _really_ been on the shoulder, then a whole lot more of the arm, the helmet, and the face would have been in focus.

The sharpnesss standard underlying 'depth of field' is rather arbitrary and for your EPL7 works out to a pointsource projection of four pixels in diameter. In other words, DoF may not be for pixel peepers. Plus, it assumes that focus was really nailed, which it most likely wasn't when you shoot a moving person through a handheld supertelephoto lens.
Maybe you shoot start by establishing the sharpness of your lens by shooting something static at similar distance, aperture, etc, using a tripod and electronic shutter. Then you'll know what kind of sharpness is possible. From there, you can figure out how to achieve it in practice.

The 100-300 is not "garbage".  The trick to getting sharp results at the long end is to use an aperture like 7.1.  As for the auto focus problem, it depends a great deal on the body that you mount the lens on.  I had a Panasonic GX1 and had a hard time getting the auto focus to operate quickly.  It hunted like a beagle before settling down.  On my GX8 and GH4 the auto focus is fast and accurate.  I think that it depends a lot on the body.  My cure on the GX1 was to focus manually and that worked quite well.

One more thought about attaining auto focus and sharp results at the 300 end.  Remember to support the lens from below with your left hand.  It may sound simple, but it makes a big difference.  If you are using the LCD and holding the camera out to compose and focus, you may not have adequate support.