Carl Zeiss Hologon - history, versions, knowledge, links, pictures

[sweat100]

The hologon has stirred a lot of interest in me lately. I am trying to understand the Contax G 16mm f8 Hologon that was converted to M Mount.

It seems that there are two types of conversions, i.e. permanent and non-permanent using a M Mount housing adapter to insert the lens cells.

For permanent conversion, I have seen that the focusing lever on the lens for some permanent conversions has to be filed back to accommodate the frame selection lever on the camera. Such modification was found here. https://www.35mmc.com/02/08/2015/zeiss-16mm-f8-hologon-review/
May I ask if you have faced this issue and was shaving off the focusing lever the only way out?

For non-permanent conversion, I did not see that there is such as issue to shave the focusing lever on the lens. This leads me to wonder why. Is it because the lens actually sits further out (hence more clearance) or is it because the M Mount housing adapter has been redesigned such that there is enough clearance. If the lens sits further out, wouldn’t there be infinity focus alignment issue?

 

[Rayt]

I am interested in the converted Hologon as well for Leica digital. Is the center filter necessary or can the fall off be effectively corrected in post?

 

[menos]

I am interested in the converted Hologon as well for Leica digital. Is the center filter necessary or can the fall off be effectively corrected in post?

I HIGHLY recommend to use the filter, ESPECIALLY on a digital sensor.

The extreme light falloff on a digital sensor is MUCH more pronounced then on film as unfortunately light is drastically cut off at the edge zones where the deep sensor wells of the sensors simply do not receive the light as the center of the image receives as of the very, very deep rear element being so close to the sensor.

A digital body is simply not the ideal body to use the Hologon on (if you can, shoot it on film).

But - I quite like the results of the Hologon in combination with a digital sensor that allows for high ISO (like the M Monochrom bodies) in combination with tools such as Lightroom, Photoshop our even tools such as corner fix if you take the time to properly set up profiles.

I always shot the Hologon this way:
- use the center filter in daylight
- correct some of the light falloff to taste with the graduated filter tool in Lightroom

I have never strived to COMPLETELY remove light falloff though and I have never ever done anything like critical architectural or landscape photography but rather quick and dirty shots - one could call it documentary or the dirty s word people use opposed to "Zoo Photography".

Here is an example with my normal editing based on a Leica M246 M Monochrom body:

Here is a comparison of the final image with and without grad filter corrections :

Remember this is a correction in Lightroom on a photo that was shot WITH center filter !

EDIT: correction, the camera with this photo was an original Leica MM (M9 based) - Man do I miss that camera - it was the very best digital sensor on any camera I have ever used and Leica has completely botched it with the later M246 sensor :-(

For completeness - I used a 0.8 stop grad filter exposure correction only on the left and right side of the image in this shot.

 

[raydm6]

Very nice results with this lens!

 

[menos]

The hologon has stirred a lot of interest in me lately. I am trying to understand the Contax G 16mm f8 Hologon that was converted to M Mount.

It seems that there are two types of conversions, i.e. permanent and non-permanent using a M Mount housing adapter to insert the lens cells.

For permanent conversion, I have seen that the focusing lever on the lens for some permanent conversions has to be filed back to accommodate the frame selection lever on the camera. Such modification was found here. https://www.35mmc.com/02/08/2015/zeiss-16mm-f8-hologon-review/
May I ask if you have faced this issue and was shaving off the focusing lever the only way out?

For non-permanent conversion, I did not see that there is such as issue to shave the focusing lever on the lens. This leads me to wonder why. Is it because the lens actually sits further out (hence more clearance) or is it because the M Mount housing adapter has been redesigned such that there is enough clearance. If the lens sits further out, wouldn’t there be infinity focus alignment issue?

As far as I know all proper conversions to Leica M mount on the Contax G mount Hologon are permanent as you will have to attach the M mount to the lens body.

There are quick and dirty "hack - conversions" where people simply remove the Contax mount and graft cheap Leica M mounting flanges to the lens body by means of three or 4 cheap screws, often badly drilled.
This was a trend when during the high times of the first full frame digital M9 many converted lenses were sold at a premium and a converted Hologon would sell for a few hundred USD more than a mint original Contax mount lens - it was a travesty.

Good conversions with visible screws were also done (but with proper workmanship and proper calibration) by people such as Don Goldberg - such conversions were worth the extra cost as one would get a properly calibrated sound lens.

The best conversions I have seen (as I bought one without knowing what a gem I had until I found out later) are ones that were converted by Mr. Zoekendorfer in Munich/Germany.
This show no visible screws on the exterior, the mounting flange surface quality of the silver chrome matches exactly the high quality chrome of the original Hologon lens body and the calibration is spot on (this is actually important as yes, you can misfocus this lens).

All proper conversions will have to have the distance lever shaved to clear all Leica M bodies frame selector levers - there is no way around that.

Sadly Mr. Zoekendorfer stopped conversions of the Hologon once CV Voigtländer released the first 15/4.5 wide angle lens in Leica mount :-(
You can only get lucky to find one of these now super rare lenses if any of their owners decides to part with it.

 

[menos]

Very nice results with this lens!

Thank you very much.
The most impressive characteristic about this lens is not actually its complete lack of distortion (a most impressive feat in itself) but how EXTREMELY sharp the ENTIRE image is from corner to corner.
I have not seen another lens that performs like this bar from perhaps a Leica 21/3.4 SEM.

It is actually now easier to shoot with cameras like the M246 with live view.
I still have to find a chance to test it on newer cameras like the M10 (I never got around measuring it and testing to mount it).