focus - allways a compromise?

[usefeet]

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Guy,

 

What's interesting here is that most of us are focussed (pun) on the M8, but these lenses

still have to match our other M cameras (for those of us that still use film cameras)!

I love the B&W results I get from using MP/M7 with TRI-X or HP5, besides the joy handling the film camera.

 

Cheers,

William

 

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

[pelikan1931]

my 50 Summilux asph is back focused, my older E43 Leitz Summilux and 90 tele-elmarit focus perfect, so are the nokton 35/1.2.

 

but when i tested the 50 lux asph, i can feel the cam has very high sensitivity/precision, because a minute turn would make the final image sharp or unsharp. I guess the manufacturing tolerence must be very high. The Cosina Nokton 35 displays the same sharpness at three given setting whereas in 50 lux asph, the three will look totally different.

 

reading through the thread, it also makes me wonder how much Leica's manpower is engaged in tuning those returnee, instead of employed making new lens?

 

and for those guys who have sent their lens back to solms,do leica charge you?

[tom0511]

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.

 

I adjusted the M8 that it now shows less FF, nearly good with the 35lux, Noctilux and 50Zeiss, therefore even a little more BF with the 50/1.4asph.

I have to recheck infinity focus, since I now feel the longer the distance the more the focus changes from slightFF to slight BF with some lenses.

But I will first justshoot with the equipment for a little while to see how it works out for me.

As soon as I get my hands on a 2nd M8 I will see if it behaves the same way like mine or not.

Now I have at least the feeling that I can use my fast lenses (besdies the 50/1.4asph) at medium distance-which is where I mainly need them to work.

I feel I have to send in the 50/1.4asph a second time because it behaves different from all other lenses I own showing BF.

 

cheers and thanks a lot for the feedback, Tom

Still envious if I think of guys perfectltly aligned equipment

Still thinking Leica should decrease their tolerances. If we send in a lens or a M8 we should be able to rely that its fine now.

[Guest GuyMancusoPhoto]

Guy,

 

What's interesting here is that most of us are focussed (pun) on the M8, but these lenses

still have to match our other M cameras (for those of us that still use film cameras)!

I love the B&W results I get from using MP/M7 with TRI-X or HP5, besides the joy handling the film camera.

 

Cheers,

William

 

 

Well the real trick in all of this is making sure the M8 is correct to start and from what leica has told me when i was in Solms and we asked about this. First they said get a lens like a 75 lux , cron or 90 apo and see where these lenes fit in regards to focus. Reason is these have the tightest tolerence. Now normally if these are working good than the chance everything else falls into place and if not than they may have to adjust the other lenses. Here is what i did on the last go round . Ray Harms came over with a body that just came back from leica NJ that was about as perfectly calibrated as you can get . than we tested everything of mine. One M8 was out and my 50 lux , 35 lux focus shift, and my 135 apo were off. i sent the one M8 in and 50 and 135mm and Robert called me and said that my M8 was out and they adjusted that than went after the 50 lux and 135mm with adjustments and shims. All that came back perfect and also checked out with my other M8. Now after something like this if it goes out again than most likely it would be the M8, lenses are not going to change that often after you have them correct. trick once all this is done and if it changes than the Hex screw could be the easy adjustment. i would advice using a lens that is not suspect to issues like the 35 lux which does have some focus shift . Use a lens that you can trust or has not been a issue with many others like a 75 cron or 90 cron. Check there and see where everything balances according to them.

[usefeet]

Thanks for the detail Guy,

 

Checked all my lenses carefully (used the 1.25 magnifier), and discovered one referrence lens I can use.

BTW, turns out this lens is a 90/2.8 (current Elmarit-M).

 

It's good to know your tools and their limitations, and in case/thread, if you like shooting short depth-of-field images.

 

Thanks again.

[ho_co]

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

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

Tom--

According to E Puts, Leica lenses' focus should be spot on when wide open. In the case of the 35/1.4 Asph and the 50/1, the lenses are designed to shift focus, so it may be that Leica has adjusted them to a kind of compromise, thinking that is what you want. (I believe that is one of the possible solutions mentioned by the LFI article.

 

Similarly, as you're aware, the C-Sonnar is intended to frontfocus wide open, so you've asked them to reset it somewhat.

 

As Guy and others have implied, be sure the camera is set properly before you worry about lens focus. Although some folks here have done their own rangefinder calibration and are happy about the outcome, IMHO one is a bit off track when one first adjusts his own body and then asks whether we need to accept compromise.

 

In other words, to my way of thinking you'll be engendering the compromise by adjusting your rangefinder. All the lenses should work just fine on all bodies. The M8 requires tighter tolerances than earlier bodies, so it shows flaws more quickly. Get it adjusted by Leica first, then start checking the lenses.

 

Just my opinion; I don't want to argue with those who feel their own rangefinder adjustments are as good as Leica's, but I think there's little chance of that being the case.

 

--HC