35/ 2.5mm Pancake lens (LTM)

[Sonnar2]

In a couple of my recent backlight landscape shots I noticed some flare with my Canon 2/35mm that is a bit annoying. (I've read that the 2/35 Summicron has the same sort of flare)

Lastly, I've got a 2.5/35 Pancake ser.I for a good price. Therefore my C/V 1.7/35 is for sale now. Never got happy with that lens due to it's protruding size for a base package (and to be honest; mostly don't need the speed). That's the main reason I haven't bought the ZM Biogon 2/35 yet.

Anybody know how the Pancake Skopar behaves with backlight?

I've read something about optical design improvements for the new version-II pancake, enlarged backlens or something, which required M-mount. Do they differ really?

cheers, Frank

 

[markinlondon]

Flare seems quite well controlled in the PII as THIS SHOT shows. I think the 35 Skopars are very close in performance

Mark

 

[laptoprob]

Bear in mind the Pancake is a fantastic lens but high in contrast! That is the reason I wint to the old Canon 35/2,8 and am now comparing to the Ultron 35. First results in low contrast light show the last two lenses are very similar in that aspect.

 

[Sonnar2]

I have a Canon 2.8/35, results are quite pleasent but this is the king of flare among my wideangle lenses -- opposed to the Canon 3.5/28mm of the same vintage.

 

[rxmd]

I've read something about optical design improvements for the new version-II pancake, enlarged backlens or something, which required M-mount.

I've got the suspicion that Cosina is producing some of their newer, more popular lenses only in M mount in order to get people to buy new R2's and R3's. The different mount only adds a millimeter or so, the rangefinder cam is in the same position anyway, I think they could well have produced both the PII Skopar and the 40/1.4 Nokton in LTM mount, but this way Cosina can sell some more bodies.

How bulky is the Ultron in practice?

Philipp

 

[Sonnar2]

Compared to the 2/35mm Canon the Ultron is a big lens, in particular with the small hood it comes with (47.8 vs. 28mm from top to flange). The new Biogon is 43.3mm without hood.
-Frank-

 

[Fred]

I've got the suspicion that Cosina is producing some of their newer, more popular lenses only in M mount in order to get people to buy new R2's and R3's. The different mount only adds a millimeter or so, the rangefinder cam is in the same position anyway, I think they could well have produced both the PII Skopar and the 40/1.4 Nokton in LTM mount, but this way Cosina can sell some more bodies.

How bulky is the Ultron in practice?

Philipp

Philipp, you are probably correct although the market for Cosina is to sell as much hardware as possible and make lots money. By sticking with just M mounts they are out of the reach of the vast numbers of screw mount owners. It may also be that they have a limited production capacity and given that they are producing some of the ZM lenses some things have to give.

Now back on topic (sorry) Personally I like the 35 Ultron, yet it is a tad big but it does not take up that much of the VF for the M Leicas or a Bessa R. The Skopar is a lot smaller and allegedly is more contrasty although I have not tried one. It's worth looking at the 35 Skopar Classic, not a lot of difference in size to the M mount only Pankake II. Have a look at the Cameraquest pages from our sponsor.

 

[kbg32]

I've got the suspicion that Cosina is producing some of their newer, more popular lenses only in M mount in order to get people to buy new R2's and R3's. The different mount only adds a millimeter or so, the rangefinder cam is in the same position anyway, I think they could well have produced both the PII Skopar and the 40/1.4 Nokton in LTM mount, but this way Cosina can sell some more bodies.

How bulky is the Ultron in practice?

Philipp

The reason these lenses are in M mount is due to their optical designs which would have not been possible in screw mount. M mounts allow for larger optical designs. See www.cameraquest.com.

 

[Sonnar2]

have read that, bu back picture of the Pancake-II look like there is enough room for a screw mount thread. (http://www.cameraquest.com/voigtlen.htm)
At the Cosina website there is no hint that the optical designs of the 2.5/35 differ in any way. maybe the 1.4/40 is a different story.
cheers, Frank

 

[Never Satisfied]

Hi, I have the 35 / 2.5 Skopar and according to the Camera Quest Site, it has the exact same optical formular as the pancake II, the latter just has the M mount. Some of the research I did prior to purchasing the 35 at the Dante Stella site explained that the CV formular for this lens is essentially the same as the Canon 35 2.8?? I think.
The 35 2.5 is my favorite lens, it's sharp, contrasty, tiny and I can't recall any flare issues or maybe I just haven't shot into the light yet. There is also more than $100 difference in price between the 2 lens' even when you add the cost of an M adaptor (if you need it) it's considerably cheaper than the P-2 for essentially the same lens. Cheers N.S.

 

[Sonnar2]

No the Canon 2.8/35mm is a classical Gauss (http://www.taunusreiter.de/Cameras/Canon_Wideangles.html) typical for the early 1950's era and very compact, whereas the C/V 2.5/35 (as shown here: http://www.cosina.co.jp/seihin/voigt/v-lens/v-l-m/index.html) is longer and looks like a Biogon type... cheers Frank

 

[rxmd]

Keith,

The reason these lenses are in M mount is due to their optical designs which would have not been possible in screw mount. M mounts allow for larger optical designs.

I've read that, too, but I don't really believe this to be the case. The M mount adds about 1 mm in available lens register and is sligthly wider. The added lens register does not make much of a difference for the optical construction, because lenses can (and do) protrude back into the camera body - it does make a difference for the construction of the barrel and the layout of the controls on the lens, but there should be an extra millimeter available on the CV barrels. The added width of the bayonet throat would theoretically allow for slightly larger rear elements, but then the rangefinder cam is in the same place in the screw and M mounts - you only get an advantage out of the M mount's wider throat if the rear element is non-circular with a cutout for the rangefinder cam, because the lens gets turned about 30 degrees on insertion as opposed to 360 for the screw mount. There are some lenses with non-circular rear elements (if I remember correctly from Frank's excellent site, the Canon 0.95/50 is one), but I don't remember seeing this in any CV lens.

I think it's mainly marketing. I would be surprised and interested to hear that there is an actual technical reason for the limitation.

Philipp

 

[peter_n]

What others have said - the CV pancake 1 is a very contrasty low-flare lens that is really excellent value for money. Good construction and very short focus throw. Optically identical to the pancake 2.