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Erwin Puts at the Leica Fellowship

dhsimmonds

New member
Members of the LF were honoured to have Erwin Puts as their guest at the very recent Autumn meeting week-end of the Fellowship.

The membership were treated to both group and individual in depth Leica discussions with Erwin and some members were able to obtain his second edition of the Leica Compendium book which he kindly signed.

However Erwin came to the meeting sporting a Fuji X100 which he proceeded to use during various events over the week-end, notably a group trip to the Roman Baths at the great city of Bath. He rated the camera very highly despite it's rather quirky nature. Two other members including myself also used Fuji X100's during this week-end event.

The attached image shows Erwin Puts addressing some of the members. (Fuji X100 at 800ISO @ F2.8.)
 

Brian Mosley

New member
Cheers Dave, interesting diagram up there... what was he talking about?

I guess the X100 has some very nice strengths which complement the Leica shooter - for those willing to adjust to the rough edges of the first release.

Cheers

Brian
 

dhsimmonds

New member
Hi Brian

Well it was a great week-end as they always are with the LF but the presence of Erwin Puts was the icing on the cake!

I will try to distill that part of the discussion for you then! Don't shoot the messenger though! :poke:

Erwin went through the close tolerances required with the exact distances between the rear lens element and the film plane or digital sensor. Leica work in virtual micron machined tolerances and use very fine shims if required to obtain the perfect fit.

Leica are apparently virtually the last camera/lens manufacturer to use mechanical engineering perfect fits in production. Most interchangeable lens cameras now rely on camera software (firmware) to sort out any intolerances in fit and correct any optical aberrations.

It is why Leica lenses usually need to go back to Solms to correct any focusing problems and DSLR lenses are usually OK or can be adjusted in camera. It is one of the reasons why Leica is so expensive by the way! :rolleyes:
 

Brian Mosley

New member
Ah, thanks for your explanation Dave. Much appreciated.

One certainly pays the price for this level of engineering precision. The 'consumer' level X100 suits me fine at the moment :)

Kind Regards

Brian
 

Jan Brittenson

Senior Subscriber Member
It is why Leica lenses usually need to go back to Solms to correct any focusing problems and DSLR lenses are usually OK or can be adjusted in camera. It is one of the reasons why Leica is so expensive by the way! :rolleyes:
This reminds me I still have to send my Sony a850 in for service since it can't focus properly to infinity and never did. Even if it's a warranty repair it's a lot more hassle than adjusting the rangefinder or a lens for the M9. Those I can have back in about two or three days. Sony takes so long it's hard to plan around. So I'll take a mechanical assembly that can be adjusted by a competent technician any time over electronic adjustments and manufacturer board swapping.
 

Paratom

Well-known member
Hi Brian

Well it was a great week-end as they always are with the LF but the presence of Erwin Puts was the icing on the cake!

I will try to distill that part of the discussion for you then! Don't shoot the messenger though! :poke:

Erwin went through the close tolerances required with the exact distances between the rear lens element and the film plane or digital sensor. Leica work in virtual micron machined tolerances and use very fine shims if required to obtain the perfect fit.

Leica are apparently virtually the last camera/lens manufacturer to use mechanical engineering perfect fits in production. Most interchangeable lens cameras now rely on camera software (firmware) to sort out any intolerances in fit and correct any optical aberrations.

It is why Leica lenses usually need to go back to Solms to correct any focusing problems and DSLR lenses are usually OK or can be adjusted in camera. It is one of the reasons why Leica is so expensive by the way! :rolleyes:
While I dont like the fact that I sometimes have to send in Leica M lenses for calibration it is obviously not the case that SLR lenses/DSLR-AF systems would not suffer from accurancy problems.
I have used both 2 smaples of a 7d and 2 samples of a K5 with various lenses and could both not get to focus consistent and reliable with faster lenses, even with focus fine adjust (which can be a pain, one day you think you have calibrated your camera fine for a certain lens, and next day the same combo proofs you the opposite).
On the other side I have had good experience with Nikon AF.
I believe that softare correction/fine adjust is good to have, but there is the danger to allow too wide tollerances and just rely on SW...
 

dhsimmonds

New member
While I dont like the fact that I sometimes have to send in Leica M lenses for calibration it is obviously not the case that SLR lenses/DSLR-AF systems would not suffer from accurancy problems.
I have used both 2 smaples of a 7d and 2 samples of a K5 with various lenses and could both not get to focus consistent and reliable with faster lenses, even with focus fine adjust (which can be a pain, one day you think you have calibrated your camera fine for a certain lens, and next day the same combo proofs you the opposite).
On the other side I have had good experience with Nikon AF.
I believe that softare correction/fine adjust is good to have, but there is the danger to allow too wide tollerances and just rely on SW...
I agree! I have to say though that the G and Zeiss ZA lenses on my A900 have never needed any adjustments neither has my old Minolta zoom lens. However I do have an opportunity to fine tune each lens and then store in the camera's memory so that it remembers the adjustment needed next time that I use that lens. I believe that both Nikon and Canon also have this facility on their pro-DSLR cameras?

As a matter of interest, Erwin Puts raised the point that modern high level DSLR's have more computer capability than the very earliest desk top computers! Makes one think that much more about these little and not so little wonders. :)

Electronics are rapidly taking over many aspects of our day to day life and cameras are no exception.....except for Leica of course!
 

Paratom

Well-known member
....Electronics are rapidly taking over many aspects of our day to day life and cameras are no exception.....except for Leica of course!
I think one thing has been compromised to often lately: userinterface!

Many new cameras (and this is true for other electronic products as well) are overloaded and the user interfaces are complicated and confuse.

Cellphones run all kinds of apps but have bad connection and the battery is empty after 2 days.

Cameras with 5 AF modes but none of them being reliable, cameras with 10 frames per second but the viewfinder blacks out after the first image and you can see the subject, etc etc.

AF lens fine calibration for me means that the customer has to adjust something which should be adjusted from the manufacturer upfront.
I find the idea of the S2 good, to measure the values of the lens, store that on the chip of the lens and communicate it to the camera AF.
 

Jan Brittenson

Senior Subscriber Member
However I do have an opportunity to fine tune each lens and then store in the camera's memory so that it remembers the adjustment needed next time that I use that lens.
This unfortunately doesn't work if the imager is too far back; no amount of AF micro adjustment will make the lens focus past infinity. It's simply not physically possible. Sony-Minolta lenses have a hard stop at infinity. The micro adjustment ONLY corrects for discrepancies between the focal plane and the PDAF sensor plane, but there are many other plausible root causes.
 

kevin2i

New member
Canon's micro-adjustment is one constant compensation. Unfortunately some lenses (such as 50/1.2L) experience focus shift. Micro-adjustment cannot correct focus shift.

Some lenses may experience focus shift at different distances. Near-focus at 1m, while perfect at infinity. Micro-adjust for 1m - and then infinity is off.

Some Zoom lenses may need different adjustments at different focal lengths. Micro-adjustment will not help.

Erwin Putts' discussion on small tolerances certainly can be extended to DSLR mirror and screen tolerances. As MP's increase - tolerance requirements decrease.

A rangefinder or SLR system are engineering solutions required for film rolls or compactness. The system Matthew Brady used is superior to 35mm solutions. Focusing on the film (sensor) plane eliminates focus-estimating devices (rangefinder, SLR mirror).

A 32-40MP Leica M10 will require even tighter tolerances. Sending camera/lenses in for calibration is tedious (my f/1.0 nocti is in for calibration, sent in July 1).

Bring on the EVF's. Modern-day ground glass.

First FF Nex 7 style camera gets my money (M-mount compatible, of course - and Nex 7 is on order).
 
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