Voigtlander Bessa I & close ups.

I just purchased a 1950 Voigtlander Bessa I folder, with the Voigtlander Vaskar 105mm f/4.5 lens. It uses 120 film, & produces a whopping 8 frames of 6x9 cm per roll. I got the mask for it also, & can get 16 frames of 6x4.5 cm per roll. I do not have the Voigtlander Focar 1 or 2 close up aux. lenses, but do have the Series VI Kodak Portra #1, #2, & #3 close up aux. lenses. Does anyone out there in the ether know if the focus charts for the Portra lenses work with the Voigtlander 105mm Vaskar? Thanks. If push comes to shove, I can open the back, block the shutter open, & put a ground glass of sorts on the film plane, & then focus & measure, etc., to see if the charts for the Portra lenses work for this camera or not. If not, I could, given the time, produce my own charts, but, whew, I get tired just thinking about it.

Congratulations on the Bessa 1.

These 6x9 folders were surprisingly good.

 

You may not need to recreate the charts entire. (LINK), you could try just one measurement to see if it corresponds to the charts you have.

Well, I went the route of blocking the shutter open, & putting a piece of clear mending tape across the film plane, then putting on the Portra lens (+1, then +2, then +3), & looking at the 'ground glass' while moving the subject back & forth, & noting the distance from the aux. lens when the subject is in focus. I got the following: Portra +1: (Camera scale focus point in feet - distance lens to subject in inches) Inf - 35.5"; 60' - 33.75"; 'oh mark' - 31.5"; 20' - 30.5"; 15' - 29 3/8"; 12' - 28.5"; 'triangle mark' - 26.5"; 10' - 26"; 8' - 25.25"; 7' - 24.75"; 6' - 22.5"; 5' - 21.75". I'll post the other two lenses in another comment in this thread.

Congratulations on the Bessa 1.

These 6x9 folders were surprisingly good.

 

You may not need to recreate the charts entire. (LINK), you could try just one measurement to see if it corresponds to the charts you have.

 

Yes. I tried that & figured quickly that they weren't the same. They're close, but not quite. So, I bit the bullet & went with the whole enchilada. Thanks for the reply.

Portra +2: (Camera scale focus point in feet - distance lens to subject in inches) Inf - 18.5"; 60' - 18"; 'oh mark' - 17"; 20' - 17"; 15' - 16.5"; 12' - 15.75"; 'triangle mark' - 15.5"; 10' - 15 3/8"; 8' - 15.25"; 7' - 15"; 6' - 14.5"; 5' - 14.25".

 

 

 

Portra +3: (Camera scale focus point in feet - distance lens to subject in inches) Inf - 13"; 60' - 12.5"; 'oh mark' - 12.25"; 20' - 12"; 15' - 11.75"; 12' - 11 3/8"; 'triangle mark' - 11.25"; 10' - 11 1/8"; 8' - 11"; 7' - 10.75"; 6' - 10.5"; 5' - 10".

I'm sure that I didn't get it all, that there might be a mistake. I'll try again, & verify the results, then actually try my own findings & run some film through the camera.

thanks.

thanks.

 

Do you think that these aux. lenses would have a linear relationship between scale focus marks & actual distance? Or would it be some kind of a curve? I'll plot these data points on some graph paper & see if the locus of points is a straight line or a curve. Perhaps I can improve the accuracy of this effort. I'll post what I find.

OK. I went back & used a better subject, one with printing on it, & re-measured the distances, & found the previous measurements were not correct.

 

Here are the new ones:

 

Portra +1: Inf - 38 3/4"; 60' - 37 1/2"; 'oh mark' - 36"; 20' - 33 9/16"; 15' - 32 3/8"; 12' - 30 3/4"; 'triangle mark' - 30 3/16"; 10' - 29 5/8"; 8' - 27 3/4"; 7' - 26 13/32"; 6' - 28 1/16"; 5' - 23 3/4".

 

Portra +2:

Inf - 19 1/2"; 60' - 18 3/8"; 'oh mark' - 18 5/32"; 20' - 18 1/8"; 15' - 17 3/4"; 12' - 15 3/4"; 'triangle mark' - 17 1/8"; 10' - 16 7/8"; 8' - 16 3/8"; 7' - 15 11/16"; 6' - 15 17/32"; 5' - 14 3/8".

 

Portra +3: Inf - 13 1/4"; 60' - 12 7/8"; 'oh mark' - 12 5/8"; 20' - 12 17/64"; 15' - 12 3/16"; 12' - 12"; 'triangle mark' - 11 55/64"; 10' - 11 23/32"; 8' - 11 7/16"; 7' - 11 9/32"; 6' - 11 1/8"; 5' - 11".

 

I appears that these values are close enough to the Kodak charts so as to be identical.

 

If anyone in the future finds an error in these numbers, please let me know.