Wednesday, April 08, 2020

Range Finder System

ZM 25/2.8 Biogon T*

ZM 25/2.8 Biogon T*

2.8/25 25mm f2.8




It took me quite a while to decide between the ZM 28/2.8 Biogon or the ZM 25/2.8 Biogon. Finally I got the 28/2.8 Biogon and is very happy with it. So quite a while later I bought this ZM 25/2.8 Biogon, after almost a year wait placing order for the lens during the nuclear reactors disaster in Japan, one of the likely reason causing a short of stock of these made in Japan Zeiss lenses.







I really do not believe there will be observable differences between the two, although everybody seems to comment that the ZM 25/2.8 is superior, as indicated by the MTF curves provided by Zeiss. So am I, very impressed by the 25/2.8 MTFs.



MTF curves for the ZM 25/2.8 Bigon T*




MTF curves for the ZM 28/2.8 Biogon T*




Size wise the 28mm Biogon is much compact than the 25mm Biogon. Also the 28mm is quite attractive as it can be used on most range finders without external finders, which can be a plus point in many shooting situation. The 25mm, however, will find Voigtlander R4M or R4A a very good body to work with. The ZM 25/2.8 can be used with two original Zeiss round hood and square hood. The view finder blockage on a R4* can be found here.



From left to right:  ZM 21/2.8, ZM 25/2.8 and the most compact ZM 28/2.8








Manufacturing quality wise this very recent production of 25/2.8 that I bought improves drastically from my early production badges of ZM made in Japan lenses. Now the focusing ring as smooth and well damp as the made in Germany ZM 15/2.8 Distagon and Zm 85/2 Sonnar. Well done Cosina!

I really do not do lens tests but just buy lenses and use them. But for this 25/2.8 I tried to do a comparison with the ZM 28/2.8 Biogon. The set up was fairly simple and by no means  scientific or very accurate. I set up using a Voigtlander R4M on a Manfrotto 190B tripod with 054Mg Manfrotto ball head. The camera was mounted on a Metz 60CT4, shooting with the flash almost directly bounced on the while ceiling of one of my room. The test negative was Kodak Portra 400. I decided to compare the two lenses based on same image coverage, so when shooting with the ZM 25 the set up was nearer to the test subjects. I placed a Contax RTS III at the centre of the composition, a Rollei 35RF at the left centre, and a Contax Aria on the top right corner. The photographs were shown below:



ZM 28/2.8, f5.6, focus on the RTS III at the centre of the photo.



ZM 25/2.8, f5.6, focus on the RTS III at the centre of the photo.


I had taken shots with both lenses set at f2.8 and f5.6. I decided to focus on the f5.6 pictures as I believed the f2.8 ones could not make conclusion due to high chance of focusing inconsistency between the two lenses for my set up. I got the negative developed and scanned at 16base JPG and could not see any differences. So I went back to the shop to re-scan as 63 MB tiff files and crops on computer screen at the centre, left and top right are shown below.




ZM 28/2.8                                                                                           ZM 25/2.8




ZM 28/2.8                                                                                           ZM 25/2.8





ZM 28/2.8                                                                                           ZM 25/2.8


Frankly I cannot really tell any significant differences between the two lenses. It could be both lenses out resolved the ASA 400 negative. But as what I have believed earlier, the two lenses should be equally good for most practical shooting purposes for amateur like me. Probably the ZM 25/2.8 is a good compromise if you so decide not to bring along a 21mm and a 28mm. 




Voigtlander R4M, f4/5.6 1/250, Manfrotto 190B/410gear, 22 Jun 2013.



Voigtlander R4M, f4 1/60,  22 Jun 2013.


More photos in Gallery


ZM 85/2 Sonnar T*

The Selective Sonnar

 ZM 85/2 Sonnar T*   85f2   2/85


ZM 85/2 Sonnar on a Rollei 35RF


Never really expect myself to get a range finder 85mm lens. Firstly 85mm is not my favourite focal length even on my SLR systems. Other than the few occasions I used the 85/1.4 Planar for wedding, I much prefer 135mm focal length, or the 100/2.8 Makro-Planar when I switch to Contax SLR system. But when you look at the MTF of the 85/2 Sonnar at f4, it is very tempting for me to get the lens as the 40 cycles/mm curve is the highest so far for Zeiss 85mm designs. I was given a very good offer and there it goes I have a ZM 85/2 with me.




The lens is sold with a leather pouch, like the made in Germany ZM 15/2.8 Distagon. The Sonnar is made in Germany. The same nice and well damped feeling of the focusing ring like the Distagon, more refine than the made in Japan ZMs. The aperture ring, however, is not as refine as the Distagon. But the Distagon has a much larger in diameter aperture ring, so not sure is that the reason for the different feeling. The Sonnar design is having 6 elements in 6 groups, with floating elements to ensure close up performance. When focusing, the front 5 element groups are moving with the last rear element being stationary. According to Zeiss a complicated non-linear range finder design is incorporated to ensure accurate focusing with this lens, and thus one of the reasons the high price of this lens. The ZM 85/2 Sonnar was returned to the drawing board once during its prototype testing and the present one in production I assumed is the updated design from the first prototype.



The rear focusing tap is different from the rest of the ZM lenses (the rests use circular ring). 


The lens does not feel bulky and heavy for me. It is fairly big though, about the size of a 85/1.4 Planar. I use a Heliopan straight metal hood with the lens. The tele Heliopan hood does not look nice with the lens and so I use a standard hood instead. 



Notice the f16 mark and the f11 mark is closer to each other than the rest. 



The ZM 85/2 Sonnar with a filter and the Heliopan standard metal hood. 


The MTF curves for this lens is very interesting. At f4 the 40 cycles/mm line is at 80%, the highest ever so far in Zeiss 85mm lens designs. I am surprised that the range finder design in this case is superior to the SLR design as I do not expect designer will face issues with mirror restriction even with SLR version of the 85mm. But maybe Zeiss purposely design it this way so that we have a good excuse to get the Sonnar instead of settle down with the cheaper SLR Planar.   : D


MTF of the ZM 85/2 Sonnar T*. 40 cycles/mm line at f4 is almost at 80% across the field. 



MTF of the latest ZF 85/1.4 Planar T*. 





A ZM Sonnar (left) next to a Contax Planar (right).


I have tried the ZM Sonnar on my Rollei 35RF with its 80mm frame lines. With the Heliopan hood the view finder blockage is minimal. Focusing seems possible. I am able to focus accurately to my satisfaction at f2.



f2 1/60 with Metz54MZ4 bounced and +1EV.               f2 1/125 trapped focus.


Depth of field is quite narrow, even at f4 the amount of sharpness is selective.  


f4 1/60 Metz54MZ4 bounced 


And as usual, Zeiss high speed lens renders beautifully at large aperture under low light condition. The photo below was taken at f2.8 and 1/125. I like the popping effect of my daughter and the nice bokeh in the background. Colour is rich and the contrast is smooth and not harsh, typical of Sonnar design. 



One thing I find out is that apparently range finder is quite fun even for action shot. As I am focusing with the range finder patch, I tend to press the shutter the moment the images are felt aligned and that speed up a lot not like SLR where I have to decide on focusing accuracy on a full matt screen. My son was playing basket ball and the photo was shot at f4 and 1/500. I am very happy with the sharpness and not to my original intention I captured the basket ball on the top right corner and his shadow at the bottom left corner.



Well, I like the ZM 85/2 Sonnar. Usable on my Rollei 35RF at f2, nice character of the lens, it is comfortable to use for me despite the size and weight, no regret. Unfortunately for its price, this is probably not everyone's lens but then again there are plenty of choices out there to suit everybody's budget.



  both taken at f5.6 1/500


ZM 85/2 Sonnar Photo Gallery


Note:   Zeiss seemed to stop production of this lens in the late first quarter of 2011. Zeiss did not officially announce this but the lens was not listed anymore in the Zeiss online shop. So future ZM tele lovers will have just one choice for the tele range the 85/4 Tele-Tessar.


Voigtlander R4M

The Wide Angle Shooter

Voigtlander R4M

Voigtlander R4 R4A


Voigtlander R4M with Zeiss 15mm finder, ZM 28/2.8 mounted, and ZM 15/2.8, 21/2.8.


The Voigtlander R4M is the lastest addition to my range finder camera system, got it in 2008. Actually I would prefer a R4A for shutter speed readout in the finder but this used R4M with good price came along first. The idea of getting a R4 came about because I much prefer  build in frame lines than external finder, especially for close up fast shots.

The build of the body has much improvements over the Rollei 35RF. The mechanical movements are much refined. The shutter noise is remarkably quieter than the 35RF. In fact on the internet it is commented that the shutter noise of the R4M is lower than that of the R4A. The view finder to me is as bright as the 35RF one, not brighter. The R4M offers framelines of 21/35, 28 and 25/50. The range finder patch is bigger than the 35RF. Due to the lower finder magnification to cater for the 21mm field of view I find immediately focusing is easier with the 35RF finder.

Inside the R4M finder the 21mm framelines are quite close to the edge. The additional metering information of +/- 0.5, 1, 1.5 and 2 stops is very useful. However with the Voigtlander design the lens mount is quite close to the finder window, the use of fast 21mm wide angle lenses will block the R4M finder quite a fair bit. For my case my favourite ZM 21/2.8 Biogon will block the lower right of the finder almost 25% with close up correction. As for the ZM 28/2.8 it is much better and this body is really ideal for 28mm rangefinder photography as the 28mm framelines is on its own, although for my case the use of ZM 28/2.8 Biogon with the Zeiss 25/28 hood does block the finder frame lines a little on the lower right corner.


Voigtlander R4M with a ZM 28/2.8 and Zeiss 25/28 hood. 


The next question will be the usability of 50mm on R4M. In practice I have taken shots with my ZM 50/2 at f2 with the R4M and I am quite please with the results up to 8R enlargements. Bigger enlargements I cannot comment as I do not normally print size bigger than 8R or super 8R. 


R4M, UC100, f2 1/125 ZM 50/2 T* Planar. 


R4M, UC100, f2 1/125 ZM 50/2 T* Planar. 



In conclusion, R4M (or R4A) is a very nice and compact body for rangefinder lovers who like to shoot with 28mm. It will work well with compact and slower 21mm. From personal experiences, it works fine for me with 50mm  at f2. However, for those who are very particular about viewfinder blockage and would like to work with fast 21mm and 28mm, this body may not be your choice. For me, the advantages of not using a 21mm external finder outweigh the view finder blockage.


R4M with trigger winder. 


Managed to find a way to take images of the R4M view finder. Below are images showing the view finder blockage of R4M with various Zeiss ZM lenses.


ZM 21/2.8 at infinity                                                                   ZM 21/2.8 at 0.6m






ZM 25/2.8 with 21/25 hood at infinity                                          ZM 25/2.8 with 21/25 hood at 0.6m




ZM 25/2.8 with 25/28 hood at infinity                                          ZM 25/2.8 with 25/28 hood at 0.6m





ZM 28/2.8 with 21/25 hood at infinity                                          ZM 28/2.8 with 21/25 hood at 0.6m



ZM 28/2.8 with 25/28 hood at infinity                                          ZM 28/2.8 with 25/28 hood at 0.6m






ZM 35/2 at infinity                                                                   ZM 35/2 at 0.6m






ZM 50/2 at infinity                                                                   ZM 50/2 at 0.6m


ZM 35/2 Biogon T*

The All Purpose All-round Performer




35mm not really a focal length that I use very much. I am more a 28/50 photographer than a 35 photographer. But when a wide angle of view is not necessary and good quality is important I like to use the 35mm at f5.6 to f8. The ZM 35/2 Biogon is attractive to me in 2 areas:  one is the amazing near zero distortion performance, and the other is the moderate fast  speed at f2.

 Rollei 35RF, UC100, f2.8 1/60, 21 May 2008

Since I already have the 40/2.8 Sonnar it is difficult for me to get the 35 Biogon. But one day I saw a good offer of the lens and so went ahead to get it. The 35/2 Biogon is good when I just want to bring one lens at fast speed. It is also more confident to use at f2.8 compared to the 40mm Sonnar at f2.8. At f5.6 and beyond they are comparable in performance. The HFT 40mm has the usual Rollei brilliance whereas the 35/2 is slightly more neutral in colour rendering. The Biogon is also better with human at corners of the photo.

Now Zeiss offers two version of the 35mm. One is the f2 Biogon, and the other is the compact f2.8 C Biogon.


Rollei 35RF, UC100, f4 1/250, 10 Feb 2008 


Rollei 35RF, Portra 400,
f2 1/30 20 Oct 2012




More photos in Gallery 


ZM 28/2.8 Biogon T*

The Compact Wide Angle     ZM 2.8/28 Biogon T*





28mm is a focal length that I like very much. I used a lot of 28mm with my Praktica PB system. When I switch to Rolleiflex QBM only Zeiss 25/2.8 Distagon was available. Now my Contax SLR I use the 28/2.8 Distagon, which performs very well to my expectation.


Rollei 35RF, UC100, f4 1/125. 29 Mar 2008 

The ZM 28/2.8 Biogon seems underrated, especially when comparing its MTF against the very popular and probably the highest resolution Zeiss ZM 25/2.8. On paper the ZM 28 Biogon MTF is comparable to the C/Y 28/2.8 Distagon, not very much superior other than the better distortion control. I own the 21/2.8 ZM Biogon, which has a very similar MTF to the 25/2.8 ZM Biogon. Comparing the photos taken by the ZM 21/2.8 and the 28/2.8, I am fully satisfied with the performance of the ZM 28. Perspective distortion is still tricky despite it is not as wide as the 21mm. Corner performance is very good and overall a lens very comfortable to use. It is a compact lens and can be used confidently wide open at f2.8. Bokeh at f2.8 is typical of Zeiss and is nice. I normally use the 28/2.8 ZM Biogon with the entire viewfinder of Rollei 35RF viewfinder. Sometimes I use it with the old Zeiss Ikon 436 exernal finder with very odd frame lines for 30mm, 40mm and 75mm, and with close distance parallax correction. One main consideration of me getting the 28mm over the 25mm is the possibility to frame without external finder. 



After many months of using the lens, I do get very satisfying photos from this lens. Despite a seemingly unimpressive MTFs, I would say for my practical purposes up to 8x12 prints, this lens is good enough, and in fact it is very good.



Jurong Point   17 Dec 2012

Rollei 35RF, Portra 400



Pulau Ubin Singapore   27 Oct 2012

Rollei 35RF, Portra 400



More photos in Gallery 


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