Crazy 21mm ASPH 2.8 with GOGGLES!

[gogopix]

I see the crazy offereing. TMK there are no 21 mm goggles.

eBay: Leica SuperWide Angle 21mm f2.8 Elmarit Aspherical Lens (item 160098688273 end time Mar-28-07 18:00:00 PDT)

"...Leica SuperWide Angle 21mm f2.8 Elmarit Aspherical Lens
with viewfinder!..."

Looks like somebody engineered a goggle mount and then put between the mount ring and the lens.
This should kill inifinty focus, no?

any ideas what is going on, or is Leica getting pretty far out!

trgartds

[adan]

It doesn't (or shouldn't, if it was done right) affect infinity focus. Either the lens keeps its original mount surface with the flange for the goggles added on top (not behind) the lens - or the whole rear mount is replaced with a mount incorporating the flange, and the same depth as any Leica mount (just like swapping on a coded mount in place of an uncoded one).

Such conversions have been around for a while.

The closer-than-infinity focus, if I remember correctly, is not perfectly calibrated, because the original 35mm lenses from which these mounts and goggles are transplanted had special camming to account for the effect of the goggles on the RF optical path, and, of course, the 21 has a "normal" cam. Supposedly this had little practical effect due to the DOF of the 21 lens.

Basically the goggles increase the field of view in front of the viewfinder without changing the size of the framelines inside the finder, so that (as originally intended) the subject matter of a 35mm lens is shrunk and compressed to fit in the area of 50mm framelines. Designed for the M3 (which had no 35 lines at all) but will work on later cameras as well.

Since the relationship 35:50 is about the same as the relationship 21:28 (actually 21:30 - but who expects RF frames to be perfectly accurate?) the transplant works fairly well in squeezing 21mms worth of subject matter to fit within the 28mm lines. So long as one is willing to accept some increase in bulk and weight in exchange for being able to focus and frame simultaneously.

These conversions are third-party aftermarket engineering - Leica has no part in them except for having built the original pieces on another time line (wink!).

Should work on an M8 as well as it did for film - the 28 internal lines already take care of the "crop factor".

Just another example that Leica M users tend to be hot-rodders at heart - witness Guy M. and Mark N.'s experiments in retrofitting smaller filters onto the WATE. Don't like your original Deuce coupe the way it came from the factory? Just add a 428, fuel injectors and Lake pipes!

BTW - the 35 lens from which the goggles are pirated is sacrificed in the process - since without the goggles its "alternative" focus camming is out of whack with the RF.

[billh]

Originally Posted by gogopix

I see the crazy offereing. TMK there are no 21 mm goggles.


"...Leica SuperWide Angle 21mm f2.8 Elmarit Aspherical Lens
with viewfinder!..."

Looks like somebody engineered a goggle mount and then put between the mount ring and the lens.
This should kill inifinty focus, no?

any ideas what is going on, or is Leica getting pretty far out!

trgartds

Victor

I know Bernie Boston (world's best news photographer)



had one made for him - he was going to sell it - maybe this is the one he had made.

[gogopix]

Well, I've gotten some info.

Yes there is an after market doing this,

(from some exchanges)

"...I've hear that Reinhold Mueller in Toronto does this. He and our own Tom
Abrahamsson collaborated on the idea if I'm not mistaken. No idea on the
cost - why not call Reinhold and ask him?..."

It's done by Reinhold Mueller to Tom A's design to any 21, altho' it works
best with a 21/3.4 SA, which can then be permanently affixed to your M4-p.

"...I had it done to a 21/2.8 non-asph elmarit. I love it, although it is a
little dark, and framing is inexact. It is still better than dropping,
breaking and losing V/F's. FYI, the focus link to the R/F is inaccurate
after gogglization - but with the immense DOF of the lens, I leave mine set
to 1m and don't worry about it. IF it gets critiacl close up wide open in
poor light, you might want to focus using another lens/body combo, and
transfer the distance setting.

Reinhold does a great job, it is (expensively) reversable. The cost is
slightly lower with the SA than the elamrit, but is around $500-$650.

I'm plucking up the courage to have the same done to my 24. (only lost one
finder to date!)

Best of light, and apologies to several for an on-topic post.
"
and this link
I may bid on this, as I need a 21mm


Leica and Rangefinders Forum: "Mad project" Summaron goggle question

regards

[budrichard]

This problem of how this works has been bothering me for awhile. Since a 24mm modified by Mueller is up for sale on eBay Leica Elmarit-M ?2.8 24 mm ASPH lens custom modified - eBay (item 300223125017 end time May-18-08 14:00:00 PDT) and I have 0.85 M bodies, I decided to tackle the problem which is really quite simple in reality.
The problem has nothing to do with the lens in actual use, as the googles only provide an image reduction for the viewfinder. Since 35mm M3 googles are used, thier use will provide different results on other finders, dependng on the viewfinder magnification.
The view that the googles provide is independant of the lens used but dependant on the viewfinder. Since standard M3 googles are used, the googles project a 35mm view into a 50 frameline at 0.92 magnification on an M3, which is the magnification of the M3 finder. Using the googles on any other finder is simply an inverse ratio of the finder magnifications multiplied by 35mm. For the 0.72 finder this works out to 27.4mm which is close to the 28mm framelines the 24mm lens brings up. You actually see the view for a 28mm lens and this is close enough to the actual 24mm lens in use that it works.
For the 0.85 finder, this is a 32.3mm view and not suitable for use.
For the 0.58 finder, this is 22.1mm and if these googles were put on a 21mm lens, bringing up the 28mm framelines, they would work correctly with a 0.58 finder.
Using the googles from a 135mm RF lens would work in the other way because they magnify rather than reduce.
The loss of rangefinder focusing should only affect closeup work since the focusing is not modified. Now if I could find someone that could also modify the focusing correctly and do the work on a 21mm ASPH, it might be worth the cost but I would need a 0.58 body!-Dick

[jaapv]

The 21 mm is described in Jonathan Eastland's "Leica M Compendium" I am surprised these lenses make it to e-bay. They are very rare and highly sought after. Most of them change hands within the circle of Northern American Leica lovers without ever making it to the market.

[jaapv]

Originally Posted by budrichard

This problem of how this works has been bothering me for awhile. Since a 24mm modified by Mueller is up for sale on eBay Leica Elmarit-M ?2.8 24 mm ASPH lens custom modified - eBay (item 300223125017 end time May-18-08 14:00:00 PDT) and I have 0.85 M bodies, I decided to tackle the problem which is really quite simple in reality.
The problem has nothing to do with the lens in actual use, as the googles only provide an image reduction for the viewfinder. Since 35mm M3 googles are used, thier use will provide different results on other finders, dependng on the viewfinder magnification.
The view that the googles provide is independant of the lens used but dependant on the viewfinder. Since standard M3 googles are used, the googles project a 35mm view into a 50 frameline at 0.92 magnification on an M3, which is the magnification of the M3 finder. Using the googles on any other finder is simply an inverse ratio of the finder magnifications multiplied by 35mm. For the 0.72 finder this works out to 27.4mm which is close to the 28mm framelines the 24mm lens brings up. You actually see the view for a 28mm lens and this is close enough to the actual 24mm lens in use that it works.
For the 0.85 finder, this is a 32.3mm view and not suitable for use.
For the 0.58 finder, this is 22.1mm and if these googles were put on a 21mm lens, bringing up the 28mm framelines, they would work correctly with a 0.58 finder.
Using the googles from a 135mm RF lens would work in the other way because they magnify rather than reduce.
The loss of rangefinder focusing should only affect closeup work since the focusing is not modified. Now if I could find someone that could also modify the focusing correctly and do the work on a 21mm ASPH, it might be worth the cost but I would need a 0.58 body!-Dick

The info in the e-bay blurb is incorrect. The lens cannot be used without the goggles. Part of the Tom Abramsson modification process is adjusting the helicoid to match the magnification of the goggles.

[budrichard]

Question to seller "Can you please tell me if and how the lens can work correctly without the googles. "

Answer from seller "I can answer the first part of your question with complete confidence, as I have used this lens with and without the goggles, always finding that the rangefinder was completely accurate in either case. I also extensively tested the lens when it was first sent to me by Reinhold, and was awed by its performance in every way, particularly at wider apertures. "

It may be that the DOF for the 24mm is so large that if the lens has been modified for focusing, that it really doesn't matter?

In any event for me, since I have 0.85 M's, I have determined based on the calculations I did, the lens is not useful. What would work for me is a modified 21mm on a 0.58 finder M.

Does anyone know of anyone currently doing this type of work?-Dick

[budrichard]

Originally Posted by jaapv

The 21 mm is described in Jonathan Eastland's "Leica M Compendium" I am surprised these lenses make it to e-bay. They are very rare and highly sought after. Most of them change hands within the circle of Northern American Leica lovers without ever making it to the market.

I have seen a few for sale on eBay over the last year or so.-Dick

[doubice]

I own the 21mm ASPH with goggles, originally modified by Rheinhold Müller - have known him personally and followed his progress from Carveth Canada, to Wild Leitz Canada (Canadian Leica agents), to the time when he ventured out on his own. Truly a master technician, who tackled any challenge.

I don't believe Tom Abrahamsson was modifying the helicoid - the only way to adjust for the focusing discrepancy with the goggles would have been to re-grind the focusing cam. Once that is done, the lens would not focus correctly without the goggles.

What the seller of the 'goggled' 24mm ASPH states is incorrect - the lens simply cannot focus accurately with and without the goggles. The goggles not only change the angle of view but also change the linearity of the focusing distance. Many threads can be found where questions are raised if the 35mm goggled lenses for M3's can be used on M2 (4, 5, 6, 7 etc) without the goggles. The answer is yes, they can be used, but rangefinder focusing will only be accurate at infinity. Even the focusing scale would not be correct for 'guestimating' the distance.

The way the goggles work is very simple and not dependent on the magnification of the M's finder (0.58, 0.72, 0.85 or 0.92). Since the goggles have a magnification of 0.7, the determining factor of the final field of view is the finder frame that the goggled lens brings up.

So - my 21mm ASPH brings up a 28mm frame: 28mm x 0.7 = 19.6mm (close enough)
A 24mm lens would have to bring up the 35mm frame: 35mm x 0.7 = 24.5mm
Goggled 35mm lenses brought up the 50mm frame: 50mm x 0.7 = 35mm
Etc, etc.....

Having said all that, I use my 21mm ASPH without the goggles now - found them too cumbersome..... Go figure....

Best,

Jan

[budrichard]

"The way the goggles work is very simple and not dependent on the magnification of the M's finder (0.58, 0.72, 0.85 or 0.92). Since the goggles have a magnification of 0.7, the determining factor of the final field of view is the finder frame that the goggled lens brings up.

So - my 21mm ASPH brings up a 28mm frame: 28mm x 0.7 = 19.6mm (close enough)
A 24mm lens would have to bring up the 35mm frame: 35mm x 0.7 = 24.5mm
Goggled 35mm lenses brought up the 50mm frame: 50mm x 0.7 = 35mm
Etc, etc....."

I understand what your are saying and my 35mm Suumicron RF does indeed bring up the 50/75 pair of frame lines on my 0.85 finders. On the 0.85 finders there is a wider field of view than through the M3(increased viewable area around the 50mm frame line), so the finder increases the area viewable depending on the finder magnification but it does look like the correct field of view is determined by the frame line. But the following is confusing.

The owner of the 24mm told me, "The frame line displayed with or without the goggles attached on my .72 M body, are the 28mm lines. The lens with the goggles on, do not bring up any lines but that of the 28mm. What the goggle does, is to act as a wide angle adapter to the viewfinder, so that one sees more in the finder than one would without the goggles. The goggles obscure the 28mm frameline, but my tests of the lens with the goggles on my .72 finder, led me to use the goggles so as to have a fairly good idea of the frame."

?-Dick

[doubice]

Originally Posted by budrichard

......... But the following is confusing.

The owner of the 24mm told me, "The frame line displayed with or without the goggles attached on my .72 M body, are the 28mm lines. The lens with the goggles on, do not bring up any lines but that of the 28mm. What the goggle does, is to act as a wide angle adapter to the viewfinder, so that one sees more in the finder than one would without the goggles. The goggles obscure the 28mm frameline, but my tests of the lens with the goggles on my .72 finder, led me to use the goggles so as to have a fairly good idea of the frame."

?-Dick

I have a feeling that the owner of the 24mm lens either does not know how to use it or, is knowingly dancing around the issue. If his lens brings up 28mm frame lines, than it has been modified. On the M8, the 24mm and 35mm frame lines come up as a pair, so a 24mm lens should have the same lens mount specifications as a 35mm lens (I am not referring to 6-bit coding, just to the frame line selector mechanism design).

A 24mm lens should key in the 35mm frame because that is how the frame selector lug is cut on the lens mount from the factory. With the 0.7 magnification of the goggles, this should provide the correct field of view. Obviously, the goggles will obscure the 28mm frame lines on a 0.72 magnification finder but, it is the 35mm frame that is needed for the 24mm lens/goggle combination.

Best,

Jan

[jaapv]

As Jan correctly remarks, the goggle magnification does influence the focussing. In his Leica Compendium Johnatan Eastland states that the 21 with goggles focusses correctly. So the helicoid must have been adjusted. That is also borne out by Johnathan's remark "entailed quite a lot more of machining than he (Tom Abrahamsson) expected."
This lens focusses either correct with or without goggles. If the seller says otherwise I would be very wary....

[budrichard]

I agree with the final consensus. Thanks for replying.
The lens has been sold but I did not purchase it.-Dick