focus - allways a compromise?

[tom0511]

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For those of you who own more than 2 or 3 lenses:

Do you feel that you can have all of your lenses to focus absolutly correct?

I played with my M8 and 2mm Allenkey yesterday and it seems even lenses I sent in for focus adjustment seem to show a slightly different tendency regarding front or back focus.

Now I have an adjustment which seems liek a COMPROMISE to work with most of my fast lenses:

 

35/1.4asph (has been calibrated by Leica)- very slight front focus wide open

50/1.0 (has been calibrated by Leica)- very slight FF wide open

50/1.4asph (has been calibrated by Leica) - backfocus wide open (might be too much) at short and medium distances

75/1.4 perfect focus

50/1.5 Zeiss (has been calibrated by Zeiss for f1.5) very slight FF

90macro - just fine

 

NOW MY QEUSTION: do we have to accept such compromises? I allready have sent in 6 of my lenses for focus calibration.

If I had 1 or 2 lenses I would just send the whole package to Leica. So again-do you guys kind of accept this compromise as long as the FF/BF is not too strong. Does anybody own a set of fast lenses which all focus totally fine?

Cheers, Tom

[jaapv]

Well- the lenses you have problems with are the ones that pass in these pages all the time..So yes- I suppose it will be a compromise..... The whys and wherefores are explained in the last issue of LFI. Basically of course we are grafting new technology onto old - lenses designed for film onto a sensor, so some compromises are to be anticipated. As a matter of fact it is a marvel that most lenses perform as well as they do - other maker's problems in this respect are at least as large as this, but Leica lenses set such high standards that we naturally expect more....

Yes, all my lenses focus fine - but I am lucky as in my ignorance I happened to avoid the worst offenders.

[usefeet]

I only tested my 50mm Summilux ASPH, and 75mm Summicron ASPH (on the M8), at fully open aperture,

and at 1m range, both had front focussed (about 2.5cm forward of my object).

[tom0511]

If all of your lenses show FF you might be able to control it by adjusting your M8.

 

The tricky thing is if some lenses tend towards FF, others towards BF, even though all lenses have been calibrated lately by Leica.

[pascal_meheut]

For those of you who own more than 2 or 3 lenses:

Do you feel that you can have all of your lenses to focus absolutly correct?

 

24mm/2.8 ASPH, 28mm/2.0 ASPH, 50mm/2.0, 75mm/2.0 ASPH and Tri-Elmar 28-35-50 ASPH... They are all focusing perfectly.

[Hacker]

Can you describe how you conduct your tests? I'm interested to find out for myself too.

[Tony C.]

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As most of your lenses have been adjusted by Leica, it is likely that your M8 body needs a minor adjustment. Find the infinity adjustment threads on this forum, follow the instructions, and I suspect that most of your minor issues will be resolved.

 

One word of advice, though: when calibrating, be sure to focus on a very distant object, such as a celestial body.

 

For the record, I have used a Leica 28mm 'cron, 35mm 'lux, Noctilux, and 75mm 'cron, and only the Noctilux (currently at Leica for calibration) was slightly off (backfocus).

 

Regards,

 

Tony C.

[Guest GuyMancusoPhoto]

Both bodies and all my lenses are on target and calibrated perfectly.

[tom0511]

Both bodies and all my lenses are on target and calibrated perfectly.

 

Wow, I am impressed

I think I will try to check my lenses on another M8 and see if they behave the same.

[Eoin]

..... The whys and wherefores are explained in the last issue of LFI.....

 

LOL and that's Gospel eh!. I don't agree with LFI's comments, many lenses have exhibited back/front focus while many of the same lenses didn't. In my own case all lenses I have had with the exception of the Noctilux were spot on. The Noctilux was sent back for calibration with my M8 and was returned in much the same condition. I queried leica as to how a lens can not attain correct focus at apertures between f:/1.4 to f:/5.6 at a distance between 1.5 to 3 meters. The workshop replied they tested it before sending it back but now the Quality management want to review it. If it is an inherent trait of the lens when coupled with a M8 then so be it....then the lens is not fit for purpose IMO. How can one be expected to accept any lens irrespective of cost to focus 2-6 inches behind the focal point. In my case both before and after the Noctilux went to solms if I focused on the eyes all I got was the ears in focus @ f:/4 at 2.5 meters and this was plainly obvious. So it's back in Solms as I write and I've made my feelings known that unless it can preform, it is useless to me. So I await their findings with anticipation.

[Guest GuyMancusoPhoto]

Wow, I am impressed

I think I will try to check my lenses on another M8 and see if they behave the same.

 

So am I. LOL

 

First i made sure both bodies were than tested all lenses and 2 went in to get shimmed.

[michael_b_elmer]

4/16-18-21, 2.8/24 asph, 2.0/28 asph, 1.4/35 asph, 1.0/50, 2.0/50, 1.4/75, 2.8/90 TE - all work perfectly.

[glenerrolrd]

For those of you who own more than 2 or 3 lenses:

Do you feel that you can have all of your lenses to focus absolutly correct?

I played with my M8 and 2mm Allenkey yesterday and it seems even lenses I sent in for focus adjustment seem to show a slightly different tendency regarding front or back focus.

Now I have an adjustment which seems liek a COMPROMISE to work with most of my fast lenses:

 

35/1.4asph (has been calibrated by Leica)- very slight front focus wide open

50/1.0 (has been calibrated by Leica)- very slight FF wide open

50/1.4asph (has been calibrated by Leica) - backfocus wide open (might be too much) at short and medium distances

75/1.4 perfect focus

50/1.5 Zeiss (has been calibrated by Zeiss for f1.5) very slight FF

90macro - just fine

 

NOW MY QEUSTION: do we have to accept such compromises? I allready have sent in 6 of my lenses for focus calibration.

If I had 1 or 2 lenses I would just send the whole package to Leica. So again-do you guys kind of accept this compromise as long as the FF/BF is not too strong. Does anybody own a set of fast lenses which all focus totally fine?

Cheers, Tom

Just a quess....your M8 has a slight front focus..the 75 has a slight back focus(which is common) and the 50 1.4 has a large back focus (which is also common) . This was driving me crazy until I had Solms adjust both my M8 s to the exact same specification. If I am right ..all the lenses that have been calibrated except the 50 1.4 are consistent.

[bradreiman]

i adjusted my body myself-all my lenses focus beautifully...B

[usefeet]

Who shimms the lenses?

..thanks

 

So am I. LOL

 

First i made sure both bodies were than tested all lenses and 2 went in to get shimmed.

[usefeet]

i adjusted my body myself-all my lenses focus beautifully...B

 

I must have missed the article on adjusting the M8.

How do you adjust the body to match the lens

 

William

[Guest GuyMancusoPhoto]

Leica can shim them if needed, that is how they calibrate.

[Tony C.]

I must have missed the article on adjusting the M8.

How do you adjust the body to match the lens

 

William

 

William,

 

Adjust the body to infinity using the technique described on the following thread. Be SURE to use a distant object such as a star, rather than a relatively close object.

 

http://www.l-camera-forum.com/leica-forum/leica-m8-forum/13933-new-backfocus-thread-solution.html

 

Then, test all of your lenses. If all but one or two focus correctly, then you probably have issues with those lenses, and should consider sending them in. If you have problems with most or all of them, then the body may need further adjustment (by Leica).

 

Regards,

 

Tony C.

[ns_ng]

Hi,

 

My M8 and my 35 'Cron (pre-Asph) just came back from Solms. This was the second time the M8 went back for RF adjustment. I found out that nealy all my lenses, 21 Asph, 35 1.4 Asph, 35 'Cron, Noctilux, 90 Elmarit and 90 AA all had focusing issues. I confirmed this by using my M3 for comparing the focusing. I decided to send the M8 for rf adjustment plus the 21 and both 35's for encoding. The M8 came back and it appears fine with both the 21 and 35 1.4 Asph, but it was totally out with the 35 'Cron. Both the M8 and 35'Cron were sent back to Solms again. After two months, they came back and so far the focusing with the 21, both 35s and 90 AA look fines. But I still feel there is a slight front focus with the Noctilux. The only lens that does have any issue is my new 28 'Cron. But Solms still did not do anything with a bright pixel that appears at high ISO or long exposure.

 

N.S. Ng

 

Zenfolio | N.S. Ng

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Hallo,

Look here: Leica M

[usefeet]

Thanks a lot Tony.

 

 

 

William,

Adjust the body to infinity using the technique described on the following thread. Be SURE to use a distant object such as a star, rather than a relatively close object.

http://www.l-camera-forum.com/leica-forum/leica-m8-forum/13933-new-backfocus-thread-solution.html

Then, test all of your lenses. If all but one or two focus correctly, then you probably have issues with those lenses, and should consider sending them in. If you have problems with most or all of them, then the body may need further adjustment (by Leica).

Regards,

Tony C.