Frameline accuracy test w/ 40 and 105mm on M2

Recently bought an M2 - my first Leica M. I want to use my 40mm

M-Rokkor (my favorite lens, used on a CL before) on that camera, and I

also got a great LTM-mount Nikkor-PC 105/2.5 recently for using on the M2.

 

Now I was wondering about how accurate those two lenses would be able

to be framed on the M2, which doesn't have framelines for either lens,

so I made a little test:

 

I mounted scales on a wall, with a broad line that I tried to match

with the centers of the framelines on the (tripod-mounted) M2, and

with a scale showing (in cm) how well the negative corresponded with

the framelines.

Distance from the camera to the wall was about 1.4 m (about 4.5 ft) -

this was chosen due to space in the room I was doing this, due to the

minimum focussing distance of the Nikkor (4 feet), and due to the fact

that at closer ditances, the field shown by the framelines will be

smaller/show less than at farther distances (and for me, cutting off

something is more of a problem than including too much...)

 

I also included my LTM-mount Canon 50/1.8 II, VC Color-Skopar 35/2.5

and VC Apo-Lanthar 90/3.5 (which will be replaced by the faster

Nikkor) in the test.

 

Please disregard the bad quality of the scans (they were done with a

flatbed with TPU, and I did not pay any attention to dust and image

quality, after all, it was the result that counted...). The

'vignetting' is actually light-fall-off from using my desktop lamp as

a 'spotlight'...

 

Oh, and I also did the same test with the CL - still need to scan the

results, though...

M2, Color-Skopar 35/2.5, 35mm framelines:<div></div>

BTW, the tiny lines on the scale are 1 cm steps, the medium ones are 5 cm, the long ones are 10 cm steps.

 

Oh, and the crappy playtic neg holder on the scanner did not allow me to always include the rebate outside of the frame on the neg - sometimes it is visible, where it is not, you have to believe me that the edge of the neg. matches the edge of the scan...

 

M2, 40mm M-Rokkor (CLE-version), 35mm framelines:<div></div>

As you could see in the last pic, at this close distance there are about 5 cm less on the neg on all edges than what was framed.

 

I guess at farther distances, or if using the inside edges of the framelines instead of the centers, coverage would be about 100%.

 

Next image:

M2, 40mm M-Rokkor, 50mm framelines<div></div>

M2, Canon 50/1.8 II, 50mm framelines<div></div>

M2, Voigtl�nder Apo-Lanthar 90/3.5, 90mm framelines<div></div>

M2, LTM Nikkor P.C. 105/2.5, 90mm framelines<div></div>

As you could see, with the 105mm lens only about 2 to 3 cm are missing all around - for me, I think I can live with that, especially since I bought this lens for concert photography, where it will not be used at close distances, anyway, so the mis-match is less visible.

 

Now, with the 40mm, I think, with carefull framing it is quite useable with the 35mm frames - for spontaneous, fast shooting, where you might need an 'error margin', the 50mm framelines might be the better choice.

I will file down my 40 to bring up 35mm framelines, though (and to all who advise against this - no, I will NEVER EVER sell this all-time favorite lens of mine, so I don't care about resale value; and, no, I am not the least bit interested in getting a CLE, and on my CL the 40mm framelines are always visible, anyway).

OK, just finished scanning the CL negs - apparently, the film does not sit exactly in the center of the film gate of my CL - the frames seem to be slightly closer to the upper edge of the film strip, that's why I could not include the lower edges of the negs with my scanner...<div></div>

Thank you for this, Roman! I would like to modify my 40mm Rokkor lens too. When you do yours, could you snap a digi-pic of the process? I still don't know exactly where to file, even though I've read the posts that have discussed this.

Apo-Lanthar on the CL<div></div>

Frank,

look here:

 

http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00CcwG<div></div>

40mm M-Rokkor w/ 40mm framelines - strangely, the 35mm lines on the M2 seem to be the closer match...<div></div>

35mm Color Skopar w/ 40 framelines<div></div>

As you can see, there's not a lot of difference between the angles of view of the 35 and 40mm lenses...

 

Finally, I also mounted the Snapshot-Skopar 25/4 on the CL and used the Voigtl�nder finder for framing (that's the newer version with framlines). The dotted line close to the upper edge of the pic, with the caption 'Parallax Mark' shows where the dotted line in the finder (intended for close-up pics) is located.<div></div>

I have no idea what you're showing here. But when I tested my 40mm Cron and 105 Nikkor at 15 feet (M4), I found that the 35mm lines were too far off the be of much use, while the 90mm lines were almost perfect for the 105. On the M6, the 35mm lines were perfect for the 40mm Cron at real working distances.

>I have no idea what you're showing here.

 

Maybe I can make it clearer with the following illustration:

 

I mounted those scales so that the RED lines would sit right in the center of the framelines in my M2's finder; the scales show steps with 5, 10, etc. cm (shown BLUE in the illustration).

If there is more on the neg than the finder showed when taking the pic, the red lines will be inside the negative'S edges - OK, I should have done a scale for that, too, but I was only interested in what got cut off); if there is less on the neg than what was framed, the red line will be outside of the negative's edges; the edges will fall on some point on the scale, so you can see how many cm. got cut off.

 

Eg. you are trying to frame a 90x60 cm rectangle, so that it correpsonds perfectly with the 50mm framelines on the M2, and you are taking the pic with the 40mm lens - according to my test, you'll get at least 10 cm more on all sides, so you are actually framing a 110x80 cm rectangle instead of 90x60.

 

Now, if you keep the 40mm lens, and frame with the 35mm framelines covering exactly that fictitious 90x60 rectangle, the neg will show about 5 cm less on all sides - so you are taking a picture of an 80x50 cm rectangle instead of 90x60.

 

Clearer?<div></div>

And the 40 with 35mm framelines...<div></div>

Great idea--very instructive! Can you repeat this with M6 framelines? (Or M7 or MP?) They are smaller than the ones on my M2.

Thanks Roman!

 

It looks like I'll be stuck using the 90/3.5 Apo-Lanthar for while. :(

 

Excellent work and for my purposes the tests were as clear as a cloudless blue autumn sky. I was mainly interested in the field of view for the 105/2.5 Nikkor using 90mm framelines.

>Can you repeat this with M6 framelines? (Or M7 or MP?)

 

Rob, sure, just send the cameras over to me... ;)

Best illustration of this oft-discussed issue I've ever seen. Good work, Roman. One interesting observation. The 40 seems to show much more than what the framelines would indicate. I would guess that this is similar to Leica's thinking on the framing for the Leicaflex viewfinders, in that they felt they should show what actually shows up in a 35mm color slide once it's mounted (about 94% I think?). My 'flex negs always have more image than I saw when taking them. I'm guessing they applied the same thinking to the CL design, especially to allow for RF parallax issues.