Wide angle lenses on R-D1s

[Mark Norton]

Never heard of that before, what's the speed of the Dual Hexanon? It's possible we might see something similar from Leica.

 

[jlw]

1) The design was simply copied from the R3a, a full frame camera. It would have been better for Epson/CV to be a little less expediant and develop framelines that were more appropriate.

I compared the frameline coverage of my R-D 1 to that of my R3A and found that they are NOT identical. For example, the R-D 1's frameline for 28mm lenses (film equivalent: 42.84mm) is noticeably tighter than the R3A's 40mm-lens frameline, and the R-D 1's 50mm frameline (film equivalent: 76.5mm) is slightly tighter than the R3A's 75mm-lens frameline.

This suggests that even though the R-D 1's rangefinder optics use the same design as the R3A's, Cosina cut different frameline masks for the Epson camera rather than simply relabeling the existing R3A framelines (even though those probably would have been close enough to get away with.)

The parallax compensation mechanism wouldn't have needed to be changed: The amount of parallax compensation needed depends only on the displacement between the finder axis and the lens axis, which is the same on both cameras. The lens' angle of coverage doesn't matter, which is why cameras with multiple framelines can move all of them simultaneously to get parallax correction.

 

[yoshimura]

The M Hexanon Dual lens was a 21-35/3.4-4 limited production lens. It was produced in 2002 in a small series of 800 units reserved to the Japanese market, but a few made it out overseas (I think Stephen Gandy sold it for a while, and there is a site in the Netherlands where it is proposed for 1500 euros, not mentioning whether they have it in stock or not). The only other multi focal lens is the Leica Tri Elmar. Stephen Gandy has written a whole page on those two lenses (www.cameraquest.com/LeicaM K21 TE), and Erwin Puts posted a review of the Konica lens on his site (www.imx/nl/photosite/japan/KonicaDual/HexanonDual.)
I was a bit wary because of Erwin Puts' rating it as non stellar in the 35mm length, but I find it to be quite good actually. I go on testing it, I will post pix soon.

 

[rvaubel]

Yoshimura
I am very interested in the results of your test
Rex

 

[rvaubel]

I compared the frameline coverage of my R-D 1 to that of my R3A and found that they are NOT identical. For example, the R-D 1's frameline for 28mm lenses (film equivalent: 42.84mm) is noticeably tighter than the R3A's 40mm-lens frameline, and the R-D 1's 50mm frameline (film equivalent: 76.5mm) is slightly tighter than the R3A's 75mm-lens frameline.

This suggests that even though the R-D 1's rangefinder optics use the same design as the R3A's, Cosina cut different frameline masks for the Epson camera ...

jlw
Your right. I spoke out of turn. I have the R3a also and I just made a quick check to confirm your observations. I had assumed since the indicated framelines on the Epson don't bear much relationship to the actual FOV you capture on the sensor, that they had not developed the framelines independantly. My bad.

However, the indicated framelines still don't have that much to do with the actual capture. For instance, the 28mm framelines indicate a much narrower FOV than is actually captured by my 28mm Nokton. I don't know if this is by design or what. But for practical reasons I use the 35mm frame on my 28/35 VC minifinder which is a nearly perfect match. Of course that shouldn't be the correct frameline by the crop math either.

My point is, who cares what the math says? It is what it is. I'm only using finders or framelines that show me what I am actually getting. I'm even beginning to wonder if the theoritical crop factor applies to the actual capture on the sensor. I don't see how it couldn't but on the other hand, it seems to me that my wide angle lenses seem to capture a little more than the crop factor would indicate. Thats the next thing I would check.

Rex

 

[pfogle]

Just to throw another variable into the mix - I see that my Jupiter 8 lens has a narrower FOV than the 50mm Hexanon I had, and my 35's are all different! The Canon 35/2.8 is wider than the 35/1.7 Ultron, which is wider than the Jupiter 12, which I would guess at about 38mm (?).

 

[Mark Norton]

Effective focal length of lenses is at best an approximation, can vary slightly from lens to lens of the same type and changes as the lens to subject distance changes anyway.

Since lens design and fabrication gets more difficult the wider you go, I expect that if you take a group of 35's, they'll be different and average a little longer than the expected focal length.

 

[Didier]

Just to throw another variable into the mix - I see that my Jupiter 8 lens has a narrower FOV than the 50mm Hexanon I had, and my 35's are all different! The Canon 35/2.8 is wider than the 35/1.7 Ultron, which is wider than the Jupiter 12, which I would guess at about 38mm (?).

Focal lengths are just an approximation. It's like with car's or bike's cubics. The Kawasaki Z1000 I owned 25 years ago had 966ccm, but was very famous for being the first "1000" japanese bike. The type 2 (pre asph) 50 Summicron is said to have effective 52mm, while the new asph has exactly 50.

The effective focal length even changes for a few % when you focus from close-up to infinity. There is a term for this effect but it slipped my mind.

Didier