M8.2 Back/Front Focus: should I lose any sleep?

[adavis47]

Just worked with a professional on a photo shoot where he used his Canon 5D mark II (I think, some 20+ mega pixel machine) and a "new" lens. I was shocked when all the images came back with faces out of focus. I noticed that were the face was out of focus, the watch on the wrist of an arm across the chest was sharp. He said he manually focused the camera. I have worked with this photographer for three decades and this has never happened. Not knowledgeable enough to know the cause or if this is indeed a case of front focus, but it has me wondering how big an issue this is with the current M8.2 (soon to purchase) and current Leica lenses. Appreciate all thoughts. Thanks.

 

[aad]

Wouldn't he be able to see the focus through his viewfinder? With an SLR, it can't really front- or back-focus in manual mode.

 

[dfoo]

With an SLR, it can't really front- or back-focus in manual mode

Huh? Its basically impossible to manually focus any modern SLR as they don't have split prisms and the like.

 

[Gabriel M.A.]

Front/back focus is an autofocus phenomenon.

Correct. The M8 doesn't "front/back-focus", it's the rangefinder, and in the vast majority of cases, the user. With "fast" lenses, it may need readjusting. The worst case scenario is when both the rangefinder *and* the lens are out of alignment. But it's not the M8.

 

[Gabriel M.A.]

Huh? Its basically impossible to manually focus any modern SLR as they don't have split prisms and the like.

"Impossible"? I do it all the time with my dSLRs:



Canon 20D + 50mm f/1.8 Schneider-Kreuznach Xenar





Canon 5D + 50mm f/1.8 Schneider-Kreuznach Xenar

 

[adavis47]

Thanks for everyone's input. Photographer said he is sending lens back. So, is a problem with M8 rangefinder focus a pretty rare thing?

 

[Richard Marks]

If you do not know how to focus a ranegefinder its going to be a very common thing. It does take a little practice. You really must try before you buy. Some people just can not get the hang of rangefinders.

Good luck

Richard

 

[jaapv]

Huh? Its basically impossible to manually focus any modern SLR as they don't have split prisms and the like.

I must be pretty stupid- I exchanged the split-prism/microprism universal screen on my R9 for a full matte one - and I love the ease of focussing. Why do you think professional SLR cameras have interchangable screens?

 

[Richard Marks]

I must be pretty stupid- I exchanged the split-screen/microprism universal screen on my R9 for a full matte one - and I love the ease of focussing.

But the viewfinder in the R9 is absolutely brilliant as it is intended for manual focus and not an auto focus DSLR. I would say its a lot harder to focus a camera set up primaruly for auto focus manually as the viewfinder does not have either a full matte or split image. If I ever did buy a DSLR (and I have been tempted by the Sony alpha 900 on occasions) I would definately need some sort of split image / matte focusing aid. I am of course not going to argue about your self declared cognitive state.

best wishes

Richard

 

[jaapv]

Well, it is a DSLR, as I have the DMR attached😉

 

[swoop]

My M8 has had a focus issue from day one that I've had to compensate for. I hope to send it off for repair within the month.

 

[JWW]

If it's the M8 rangefinder, it's real easy with the allen wrench adjust. If it's the lens, need to send to Leica or DAG for adjust.

 

[Holmz]

Take a couple of shots and if they are sharp - then I would not lose sleep over it...

My friend with the 24 MPixel nikon said to me "How come your pictures are so sharp? You only have half the pixels that I have."

Said "Yeah its weird isn't it"

 

[Richard Marks]

Well, it is a DSLR, as I have the DMR attached😉

Its not an auto focus thingy is what i was trying to say!

Richard

 

[mountainrivera]

Could very well be the body. Ideally if possible, check the lens' [eformance on another body. I drove myself up the wall thinking my 90mm lens was out when it front focussed while my 50mm was fine on my M8. I spent months driving DAG nuts until I tried it on another body. Only then did I realize y camera body was out and sent it to Leica under warranty for an adjustment.

 

[Gabriel M.A.]

Could very well be the body. Ideally if possible, check the lens' [eformance on another body. I drove myself up the wall thinking my 90mm lens was out when it front focussed while my 50mm was fine on my M8. I spent months driving DAG nuts until I tried it on another body. Only then did I realize y camera body was out and sent it to Leica under warranty for an adjustment.

Really? The body was at fault? Are you sure it wasn't the rangefinder that needed alignment, as opposed to the body?

 

[jaapv]

Its not an auto focus thingy is what i was trying to say!

Richard

Autofocus is for wimps😀😛

 

[adavis47]

Sound advice. 🙂 Thanks

 

[GrahamWelland]

Huh? Its basically impossible to manually focus any modern SLR as they don't have split prisms and the like.

Damn, THAT's funny.

1) Yes you can focus MF lenses perfectly on a matte screen with or without a prism.

2) You can also use the AF focus indicator (a green dot on my Nikons) to help.

3) Even if you focus accurately on the viewscreen, it IS possible for the camera to be out of alignment such that the sensor and/or viewscreen aren't accurate. This would also be a reason for the focus to appear to be correct but actually be off in the final images.

Yes, it certainly is easier when using a screen with a prism (I miss my Katz screens - not available on D700/D3X) ... although it can also affect the metering. It would also be nice in MF mode to turn all the various AF indicators off but that's not a deal breaker.

As regards the OP's question about Leica back/front focussing - sure it can happen. It depends on your lenses and their settings, plus it could also be the RF mechanism being out too. If you are buying from new then you should reasonably expect the RF body to be correct, especially as I understand Leica invested a boat load of money in a new RF alignment rig not too long ago which is supposed to have improved the RF's. But even so, it is possible that your lenses MIGHT be slightly out, although it's pretty rare for most lenses with a few renown for mis-adjustment or focus shift with aperture (35 'lux comes to mind).

I personally had a brand new Noctilux that was out by a mile straight from the factory. This was during the Leica lens rebate hell with the first cameras where I'm sure they were overrun with shipping out Nocti's. However, no excuse for what was then a $4k lens now much more $$$$ to ever leave the factory less than perfect. $120 had it fixed by someone who cared (DAG).

 

[jaapv]

Damn, THAT's funny.

1) Yes you can focus MF lenses perfectly on a matte screen with or without a prism.

2) You can also use the AF focus indicator (a green dot on my Nikons) to help.

3) Even if you focus accurately on the viewscreen, it IS possible for the camera to be out of alignment such that the sensor and/or viewscreen aren't accurate. This would also be a reason for the focus to appear to be correct but actually be off in the final images.

Yes, it certainly is easier when using a screen with a prism (I miss my Katz screens - not available on D700/D3X) ... although it can also affect the metering. It would also be nice in MF mode to turn all the various AF indicators off but that's not a deal breaker.
).

It goes even further - with long and/or slow lenses you need a matte screen instead of focussing aids, as those will black out. Macro is much better on a full matte too.