Pre-war biogon 35mm f2.8 vs Planar 35mm f3.5

[stephen_lumsden]

I have 2 Contax ii cameras and a lot of lenses with them. I have a J-12 which is good, but sometimes, I think it could be sharper. I was thinking about getting a Nikkor 35mm f3.5 but want to be able to focus up close accurately, so it comes down to the two above (the post was biogon seems too expensive). I am looking at them from 2 reputable vendors. The Biogon is £349 and the Planar £325. I never plan on getting a Contax iia so do not mind the bulge at the rear of the Biogon btw. Both come with pouches or cases.

 

[Sonnar Brian]

The Nikkor 3.5cm F3.5 will be off, it is possible to slightly reduce the Shim for sharper focus- but not for the full range. Chances are the DOF will cover the error on film.
I've also noted more variation in the Nikkor 3.5cm F3.5: I had one in LTM that was soft, later picked up a 1949 version that "blew me away" as it was so good. The Nikkor 3.5cm F2.5 - I've noted less sample-to-sample deviation, and did shim one for Contax for an RFF member. Optimized for close-up/wide-open, stop down for infinity.

J-12: a lot of sample-to-sample variation, with those by KMZ being the best.
The Zeiss lenses: as you note, more expensive, but a safe bet. I have the Biogon "T", very good. I do not have the Planar. It is not as common as the Biogon, surprised it is lesss. Check relative condition of each.

 

[stephen_lumsden]

thx Brian. I would be tempted to get a Nikkor, but that would only tempt me to get a Nikon S2 or S3 down the road. I am sticking with Contax or Kiev. I have a Voightlander 25mm, for Nikon S, which suffices for landscapes. I did shoot my wife close up once and noticed she was sharp but not overly so, most likely at f4 the differences may be slight but noticeable.

 

[dexdog]

This is what RFF member TenEleven said about the Planar

Post-war Carl Zeiss (Opton) Planar 35/3.5 - Rangefinder Coupled - Mounts on IIa - (4 groups / 5 elements)
All coated. Rare. Brass finish. Made as a cheaper alternative to the post-war Biogon. Planar design. It offers a very punchy, vivid color reproduction that is different from almost all the other lenses in Zeiss line-up, making it the odd-man-out. The sharpness well into the corners is excellent from wide open. Perhaps not on the Biogon's level in the picture-center, however readily beating it in the corners at open apertures. There is a lot more vignetting than its more expensive brother, but I have not really managed to get this lens to produce any flare. Distortion is invisible.

 

[dexdog]

A quick pic of my dining room (yeah, I need to dust the table). Planar about 2 meters wide open, point of focus is second candlestick from the left. Straight outta camera jpeg, probably a bit overexposed but did not tweak it. This pic does not show any vignetting, but I agree with TenEleven that it will vignette more than the Biogons will, I think it shows up more in bright light. Purposely framed it this way to get the bright light streaming in from the right. Should be able to see a higher resolution image by clicking on pic and using RFF as password.

 

[dexdog]

Another pic, point of focus in on leading edge of the big grass about 5 meters, wide open. Very bright sun this morning shows the vignetting. Reduced vignetting as lens is stopped down.

 

[dexdog]

Vignetting with Planar in strong sunlight. I also see that I need to clean some dust of the sensor of the Sony a7III!

f3.5

f5.6

f8

 

[stephen_lumsden]

Vignetting at f3.5 does not look great. Or is that the sensor effect. How's the Biogon wide open?. Also I may be tempted by the half stop speed hike. Does the lack of coating on pre war lenses affect the sharpness much in comparison with post war coated ones?

 

[dexdog]

I dont think the vignetting it is a sensor effect, the Planar does not have a rear lens group that extends deep into the camera body close to the sensor. The Biogon will show sensor effects on both Sony a7III and to a lesser extent on a Nikon Z6, which manifests as smeared corners. The Z6 is better in this respect, but not immune. The lack of coating on the pre-war Biogon will not affect sharpness all that much compared to the post-war version, but will exhibit less contrast and would be more prone to flare, as expected. I may take a pre-war Biogon and Planar out today to shoot side by side.

 

[dexdog]

Planar on left, Biogon on right. You can see that the rear lens group of the Planar is deeply recessed inside the fixture. I used a set of calipers to estimate how far the rear lens group (not the lens fixture) of Planar projects out from the base of the lens mount, it is about 2mm.

 

[dexdog]

Nikon Z6, about 65 meters, used focus peaking.
Biogon, f.28


Planar f3.5

 

[dexdog]

Biogon f5.6


Planar f5.6

 

[dexdog]

Shooting a blue sky is a great way to tell when sensor needs dust removal! Also, vignetting of Planar appears to be greater on the Z6 than the a7III
Biogon f8


Planar f8

 

[stephen_lumsden]

The sky looks better on the Biogon. What's your favourite?

 

[dexdog]

The sky looks better on the Biogon. What's your favourite?

With digital cameras, I use either the CZJ Biometar or the CZ Biogon.

 

[stephen_lumsden]

With digital cameras, I use either the CZJ Biometar or the CZ Biogon.

What about film?

 

[dexdog]

When I used to shoot film cameras, generally used the 1937 Biogon