Really struggling with APO 75 f2

[anonymoose]

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I've put my M11 + 75mm APO f2 on a tripod, setup a make-shift focus checker (item + paper + ruler) and whether I focus with RF or live view it seems to be fine. I've done this at MFD as well as about 6' away.

In practice, I'd say 95% of the photos I take at f5.6 and lower have missed focus or are generally blurry even at 1/250 and 1/320. When I take the photos, I'm 90%+ certain I'm focused on the right area, but the picture that comes out says otherwise. Despite the RF patch being sharp with maximum contrast, it seems the vast majority of my pictures are front-focused quite a bit.

My make-shift focus checker tells me the lens is probably fine, so I'm guessing this is just the issue trying to RF-focus a 75mm? Anyone else have a similar experience or thoughts that might help?

[LocalHero1953]

You won't like this, but I never had a problem focusing that lens at f/2. The equivalent 90 was a bit more tricky, but still manageable. If the lens and camera are properly calibrated, then it's just practice, practice and practice. There's no easy solution!

[anonymoose]

5 minutes ago, Al Brown said:

There was a significat pre-2019 batch of 75 APOs with erratic FLE. A well documented issue (search the forum). Yours might be suffering from that issue

It does feel somewhat random when I get a picture in focus vs. when I don't. I've even tried to purposely back-focus a tiny bit since most of my OOF pictures are front-focused, but then I end up with back-focused or front-focused pictures. Can't make sense of it.

The aperture ring has quite a bit of play and the focus ring sometimes feels a little inconsistent, so maybe there's something going on with the lens. Will take it to the Leica store.

Is there a way for me to test for this erratic FLE issue myself or does Leica need to diagnose?

Edited February 20 by anonymoose

[wda]

Are you using any focusing aids, such as image magnification or  focus peaking? I find those invaluable with advancing years.

[anonymoose]

5 hours ago, wda said:

Are you using any focusing aids, such as image magnification or  focus peaking? I find those invaluable with advancing years.

I have almost 20/10 eyesight (thank you LASIK!) and even with focusing aids I seem to be having issues.

[Ecar]

It's not the easiest lens to focus in my experience, but your reject rate is way too high, esp. if focussing through LV. Just send it in for service.

[LocalHero1953]

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33 minutes ago, Ecar said:

It's not the easiest lens to focus in my experience, but your reject rate is way too high, esp. if focussing through LV. Just send it in for service.

The OP says he can focus it on a tripod, by RF or EVF, so I don't see how there's a problem with the lens. Sending it for service is lost money and a lens lost for 6 months plus.

[Ecar]

50 minutes ago, LocalHero1953 said:

The OP says he can focus it on a tripod, by RF or EVF, so I don't see how there's a problem with the lens. Sending it for service is lost money and a lens lost for 6 months plus.

FLE moving around in real life? Even if focussed somewhat carelessly, which doesn't appear to be the case here, a picture taken @ f/5.6 shouldn't be blurry. But it's indeed not my money - or my time.

[pgk]

I've had a couple of these lenses. One was poor, the other fine. I'd go for the FLE mechanism being out of adjustment if you are getting random blurry photos. This mechanism apparently has to be correctly set up and within tolerance to give perfect results. Sadly it sounds like it is in need of servicing, probably be Leica although, depending on where you are, there may be an independent  technician who can carry this out. Its one of those lenses that I'd like to have kept in some ways.

[davidmknoble]

I’ve tried 2 over the years, and focusing with an EVF is not what I want.  I shoot with film as well using a 0.85x MP, so I should be able to hit it spot on.  I can nail the 75 Summilux and the APO 90 summicron, but I gave up on the APO 75 summicron.  

[RobW0]

On 2/20/2025 at 5:17 PM, anonymoose said:

I have almost 20/10 eyesight (thank you LASIK!) and even with focusing aids I seem to be having issues.

That does not mean that it is 20/10 while looking thur the viewfinder.  

[lct]

You may wish to add 0.5 dpt. to your prescription, in theory, but better bring your camera to your optometrist or your eye doctor or an optician having the whole range of diopters, and try the values in person around your prescription. I used to do it after cataract surgery and it worked perfectly.