[Asahiflex]

I like how nowadays it's possible to mount Deckel mount lenses (DKL) to my Pentax. DKL lenses have been used on the Voigtlander Vitessa T, Voigtlander Bessamatic/Ultramatic and the Kodak Retina Reflexes. To be able to use the lenses an adapter is needed. I got a DKL to M42 adapter; this adapter has its own diaphragm ring because the lenses do not have this ring.

Today I got the Voigtlander Septon 1:2/50 lens. As the name implies, this lens has 7 elements. Its optical scheme is very similar to the 80mm f/2.8 Carl Zeiss Planar for the Hasselblad.

It looks very classy:





The two photos below are my first tries with the lens. I was surprised to find that the lens is very, very sharp wide open.

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Last edited by Asahiflex; 01-10-2010 at 01:53 PM.

[Douglas_of_Sweden]

Impressive lens and photos. May I ask where you got the adapter?

[Asahiflex]

Impressive lens and photos. May I ask where you got the adapter?

Thanks! The adapter seems to be readily available on eBay, even adapters from DKL to PK. They are not cheap though, but I have the idea that these adapters are better made than most simple metal adapters.

Just search for "DKL Retina" on eBay.

Mmm. Now I should try go find a 40mm f/2 Voigtlander Skopagon

BTW: the Septon is VERY well built. This very example is one of the best German lenses I have ever handled. Even the focusing feel is as good as with my Takumars. I was told that those last Voigtlanders were the last breath from the factory before the Bessamatics/Ultramatics were discontinued in favor to the Zeiss Contarex (Voigtlander was owned by Zeiss at that time), so they did try to make superb lenses for the last time... And at least they got it very right with this Septon.

Even Voigtlander stated that it was all about the lenses. "A Voigtlander camera, because the lens is so good". Unfortunately, they lost the battle. It certainly didn't help that a Bessamatic with Septon 50/2 was more expensive than the Rolleiflex 2.8F.

[Asahiflex]

A few more shots with the Voigtländer Septon 2/50. It still amazes me that it's so sharp and has a very high resolution wide open (as the shots below are).

[MattGunn]

After a few weekends work in the shed I have got my latest lens conversion to the point where it can be tested. The lens (shown a few posts back with a super takumar 50mm f1.4 for scale) is a Wray 36"f/6.3 reconnaissence lens which I believe dates from the 1940s. Apparently these were originally used for arial reconnaissence taking images on large format negatives (10"X8" I believe).

The attached photos bellow show the construction and the finished lens.

The first photo shows the component parts of the lens. These consist of:
The lens
A margarine tub lid (found to be exactly the right size to be used as a lens cap),
A clear plastic flange for bolting to the lens (built up from two hand sawn disks of 12mm plastic),
A plant pot with the bottom cut out (for building up the glassfiber section),
A plastic amunition transport case (salvaged on its way to a skip!)

The second photo shows the first stages of the build.
The glassfiber section has been built up around the plant pot with the plastic flange as an integral part of it. This was built up around the green plastic case to get a good fit and a layer of cling film was used as a release agent to prevent it sticking. An old bellows unit has been modified so it can be used as a focus mechanism and the mount for this has been bolted into the end of the green plastic case.

The third photo shows the above parts push fitted to show the assembly. After this photo was taken the wide end of the green plastic casing was cut of and the whole lens was trial assembled (push fitted only). Once it was dark I took it outside to find the infinity focus position using the moon as a target. Once this was found screw holes to hold everything together were drilled and more glassfiber and filler were added to the front section and sanded back to get a good finish. The glassfiber section was then painted and the inside of the green tube was lined with black paper to reduce scattered light.

The final phot shows the completed lens assembly mounted on a very heavy duty tripod (this thing is really heavy) with the Samsung GX20 mounted on the back. The tripod mount is right under the ballence point of the lens with the camera on the back. As the GX20 waights about half a kilogram you can imagine how much the lens must weigh for it to ballance as it is!

The lens is by no means finished and some work still needs to be done to improve the image quality and rigidity etc. I will post some photos taken with this once I have had a chance to sort them out.

[MattGunn]

There is not a lot of information available about this lens but the information I found says that it is generally a good lens but shows a lot of spherical aberation wide open. After taking some test shots it was quickly found that the lens is very soft wide open but improves significantly by f/8.

The contrast from the lens is quite poor at the moment. I think this is due to:
Poor coatings (not very even when examined visually)
some quite deep scratches in the front element due to poor storage
Inadequate baffles and poor internal blacking / lining on the lens tube.
There is not a lot I can do about the first two but I intend to do some more work on the inside of the lens tube. It is currently lined with crinckled black paper which is not really black enough and scatters quite a bit of light. I intend to get some black flocked paper from Edmund Optics designed for this purpose and re-line it with this.

I was not terribly optimistic about the performance of the lens with a DSLR body as it was designed for very large format film which is less demanding than small format high pixel count digital sensors. However the results are not bad so far and with a bit more PP they can probably be improved further. Both photos bellow were taken at f/8.

The blackbird shot bellow has had a contrast bost and a bit of noise reduction. Nothing has been attempted yet to deal with the chromatic aberations. This image was taken from about 15m with no cropping.

User Photo Gallery - Nature

The moon shot has had no PP other than noise reduction. The sharpness and detail are not great but it shows the very small field of view this lens gives.

User Photo Gallery - Night Scene

More photos when I have done some more development and testing.

[wallyb]

Wow, Matt! That is a lens I'd be proud to own, even considering the looks only its maker could love Awesome job!

[MattGunn]

Wow, Matt! That is a lens I'd be proud to own, even considering the looks only its maker could love Awesome job!

Thanks
Its not the most beautifull lens I have ever seen but having put so much effort into building it, its beautifull in my eyes. It has been good fun to build although its not finished yet. I spent the afternoon machining a cast brass hand wheel for the focus as the small focus wheel it had was dificult to use. Still lots do to it before starting on the next project though...
...when I brought this I also got a Bausch & Lomb 24" f/6 Aero Tessar. Unfortunately this is probably going to have to wait a while as I am due to move house very soon.

[MattGunn]

After some further testing I have figured out why all the images I took so far appeared a bit soft. It turns out that this lens is completely incapable of focusing blue light! I suspect that this is because most reconnaisence lenses were designed to be used with a yellow filter (presumably yellow gave the best contrast of interesting ground features from the air?) and so they work well with red and green light but very poorly with blue.

The following shot has very little in the blue and so was pretty good straight out of the camera. It has however had a slight increase in overal contrast and some noise reduction. This section of fence was around 100m away but the barbes are still clearly visible!

Pentax User Photo Gallery - Landscape

Given my previous experience with teleconverters and long lenses I was not very optimistic about the performance of this lens with one. However to my supprise it worked remarkably well once I had removed the blue channel from the image. This picture of the moon was a filtered B&W conversion done in Picasa.

Pentax User Photo Gallery - Night Scene

Just to show how poor the lens is in the blue the following images are the red and blue channels of the image above respectively. The green channel is almost indistinguishable from the red.

[Douglas_of_Sweden]

Matt, you are a hero. Very impressive lens and adaption!

Not he best lens for bluebirds then

[Asahiflex]

With the pre-war and uncoated Meyer Görlitz Primoplan 7,5cm 1:1.9 (c. 1938, Exakta mount on my K-7):

[Asahiflex]

OK, for fun, let's go a little further back in history...

What have we here? According to the lens name ring, it's a: Anast.-Zeiss 1:8 f-136m/m Bte Sede E. Krauss & Cie Paris No. 24017.



As per the Lens Collector's Vademecum, this lens was designed by Zeiss and made in licence by E. Krauss in Paris. Based on the serial number the lens dates to somewhere around 1896-1898, making it my oldest lens. But by no means the worst! Imagine my disbelief when I went on a walk and returned with the images below. Everything was shot wide open, with the Krauss taped to a M42 bellows, which in turn was mounted on the Canon 5D. I haven't tried it on the K-7 but will do that soon.

Remember, those are shots with a 110-year old lens!



This experience was a real eye opener for me. Will it be the same for you? Please note that the pictures *really* came out this contrasty. I think this is due to the fact that the lens is only f/8, so no large glass surfaces which cause light scattering.

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So, no need to be afraid of 110 year old lenses

[MattGunn]

6.

So, no need to be afraid of 110 year old lenses

Those are great photos, I especially like this one - the colour and bokeh is superb, especially considering the vintage of the lens. Did they need much PP to acheive this colour and contrast given the lack of coatings etc?
I don't have anything this old but I have some more vintage glass I haven't tried yet, think it may be time to dig it out...

[Asahiflex]

Those are great photos, I especially like this one - the colour and bokeh is superb, especially considering the vintage of the lens. Did they need much PP to acheive this colour and contrast given the lack of coatings etc?
I don't have anything this old but I have some more vintage glass I haven't tried yet, think it may be time to dig it out...

Thanks! The biggest surprise for me was that this is almost how it came out of the RAW file. I have developed it again, this time with default settings. It's unbelievable, but it has everything to do with the lens being only f/8. The smaller the lens elements the better (this way light scattering is avoided).

[max889]

Interesting thread. I was out of the digital slr game since recently I bought a K20D, but I was a Canon FD shooter before. Since the FD lenses are orphaned and I had a beat up but optically perfect 300/4 Canon lens that wouldn't sell for much I asked a good repairman to change the mount to K to work in preset mode. I'm getting it in the next days. Will post some pictures.