Kish Lens Tests

One of the fun things we are showing at NAB is a set of prototype Kish Lenses. This post goes into some more details about the lenses, their look, and the quality testing.

Review: (You can skip this paragraph if you already know the lens specs) The three lenses we have made are super 16mm primes in the focal lengths: 10mm, 18mm, and 38mm. The lenses are fixed focus and fixed aperture. The lenses are set to f4 and intended for indoor use. They will be able to focus on our Universal C-Mount Follow Focus Mount, which moves the lenses toward and away from the sensor on an electronically controlled rail system, that will be controlled by the crank on the side of the camera.

 

Let’s talk about the design and look of the lenses a bit first.

These lenses are designed after the style of the unique high quality prime lenses of the 60’s and 70’s. Modern lenses have twice as many elements as vintage glass, and modern lenses use special coatings to create clarity on sometimes lower quality elements, even plastic internal elements. Our lenses have a minimilist design theory only using 4 – 5 elements, and all elements are glass. We are using the shape of the glass to create the look and sharpness and not relying on coatings. We are using modern coatings on some elements. The front element, and the rear element both have modern multi-coatings on them, but all of the interior facing elements have no coatings at all. That means that when you point them at lights you get these cool lens flares that give you a great vintage look and are so hard to get on most modern lenses because of their coatings.

The real quality of vintage lenses is not the lens flare though, it’s the tight sharp feel you get, while still being flattering to people and skin.

So after 4 different lens tests and a lot of tweaking we are ready to show you some prototype lens images.

The 10mm and the 18mm are both performing up to the standards we were expecting, but the 38mm is quite a bit softer than we expected over the whole of the image. This indicates there is either something fundamentally wrong with the design, or there is a problem with the manufacturing of the samples. We are getting some more samples from our manufacturer to help us figure out which problem it is.

Keep in mind these are prototypes, that being said we are pretty proud of where we are so far with the lenses.

When we first got the lenses in we brought them over to Otto Nemenz, the guys there were very kind to agree to help us test them. In order to test lenses you need a very fancy projector.


Right away we ran into issues. Since they don’t test C-mount lenses there anymore they had misplaced their C-mount ring for their projector, but we came up with an interesting solution…

We then ran into our second problem, we couldn’t get the lenses to focus properly the way they were supposed to.

We discovered that due to a miscommunication our optics designer had compensated the Flange Focal Distance on the lenses to compensate for the optical block in the camera, but this was unnecessary since the camera mount compensates for this.

Through a lot of very precise negotiation we eventually got the images into focus. The first thing we found was that the image circle of all three lenses is really big! These lenses will come really close to completely covering M43. The larger “TV SAFE” format is full frame 35mm!

We left Otto Nemenz with a lot of good information, but I wanted to test the lenses on a camera, even though they weren’t really ready yet. Wide Open Camera offered to setup a test with a GH2 and below is what came of this test. Keep in mind these are made with the still incorrect FFD.

This is the 10mm.

This is the 18mm.

And this is the 38mm (with obvious issues)

As a reference this is a Panasonic lens.

I felt the detail and look of both the working Kish lenses out performed the more expensive Panasonic one.

After some testing we discovered that one of the elements on the 38mm was backwards. This and the improper FFD meant a trip to the machine shop.

We had the back of the lenses ground down to allow for the proper FFD, but it would mean shimming the lenses again.

This time we took a trip out to Schneider Optics who were again very gracious to let us test there. We setup the lenses on a projector and started testing the focus.

The lenses after machining performed even better than the first time.

We were getting results at 200 lines per mm

After we found all of the right shim distances we assembled the lenses with shims in place.

The 38mm got better with the machining but was still not at the performance level of the other two.

I really wanted to see what these would do with skin though, so we went back and shot these lens tests.

10mm.

18mm.

38mm.

And for reference here is a different Panasonic lens.

I put crop marks on the pictures so you can see the actual active area for M43 and for S16.

The result we think is pretty good! There is some color issues in the 10mm we are hoping to deal with a little, and the better, but still obvious fogging in the 38mm, and very tiny amount of very diffused vignetting on the 18mm. I actually kind of like the vignetting on the 18mm and it turned out to be my favorite of the lenses. I know a lot of people want the wide, but I really like the 18mm. I also thought the depth on the 38mm was really nice if we can deal with the fogging issue.

We showed the lenses to lots of people already and the response has been very positive. They are going to give you a look and a way of working that just doesn’t exist in modern lenses.

We are very interested to hear what you guys think, if you’re at NAB please come by today or tomorrow to see the camera and the lenses, we are at the Pomfort booth #C8441

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joerubinstein

About joerubinstein

Joe Rubinstein is one of the founders and CEO of Digital Bolex. At Polite in Public, a photo marketing company he also co-founded, Joe was the Chief Technology Officer who worked with electronics developers and software developers to create the Polite in Public Photobooth which helped define modern photo marketing services.

31 thoughts on “Kish Lens Tests

  1. I’ll admit I’m not really keen on the fogging but I really love the overall look and “feel” of these lenses. I like the idea of lenses that will give a look that’s reminiscent of vintage styles but in a brand new piece of glass. I’m always worried about the upkeep on older lenses. Much like the D16 it’s a great mix of traditional and modern. Can’t wait to see more.

  2. You guys are amazing. The lenses you guys are producing have SO much promise, and I’m super excited to see what can be made from them! If I could fly out right now I would. In the mean time, you’ve got a huge fan behind-the-scenes in Seattle!

  3. I’d like to know more about the rail focus system sometime. The focal lengths are exactly double in terms of 35mm equiv, or is there another, more precise magnification factor, for S16? I actually quite like that “reversed rear element” look of the 38, I’ll have to remember that when I get these.

    • You can soften a lens quite a bit by putting a ladies stocking behind the lens so it lays flat against the rear element. These lenses actually have space behind them that would work great for shoving things in there.

      Maybe I’ll do a blog post just about that :)

      When we create a prototype of the Universal C-mount Focusing System I will definitely do a post showing how it works.

      Thanks for your support :)

    • It’s pretty sharp at infinity, but it’s not as sharp as it is at 6 feet. The lens is really sharp from about 3.5′ to about 17′. We will make an out door lens, that is similar, but it will be f8 and great for out door stuff :)

  4. First off, kudos on all your incredible accomplishments with the Digital Bolex.

    Colour me ignorant, but is there some special reason that wild barrel distortion is accepted in film and video work? Freedom from this is one of my nmain reasons for choosing prime lenses.

    • I think it’s a price choice for many lens makers, you have to make the image circle of wide angle lenses so much bigger to avoid it in many cases. As you can see here our lenses that are only intended to cover S16 actually cover M43. There is a lot of barrel distortion when using it with M43, but very very little when using it with S16 as it is intended to be used :)

  5. BTW, the site’s overly zealous anti-spam engine accuses us of trying to “beat the system,” and upon our loading another page to turn cookies on for the digitalbolex site, blocked us altogether:

    Access has been blocked.
    Your IP has been identified as spam
    Protected by: AVH First Defense Against Spam

    • I know we are working on our site now. It has a lot of issues. We hope to solve them relatively soon. We don’t have someone dedicated to site maintenance, we are just too small a company right now :)

  6. I know I am not the target audience but I will buy these lenses for still photography on M43. I already have a collection of interesting c-mount and other MF lenses and yours look great. Please include them on the product page so I can sign up to be notified of their availability. Awesome work guys. If you do anamorphic it will be a killer, think of all the GH shooters.

  7. Friend of mine has invested in the D16, so sometimes I check out the site to see what’s going on. Gotta say I’m really impressed by both the sheer amount of work put into both the cam and lenses, as well as the results. The aperture seems a bit stopped down for a prime, but I suppose brightening the image in post will take care of that, since it’s in RAW.

  8. I think your camera and lenses are fab! You are soooo inspirational and it takes guts to work all this out with commitment. You are history makers and innovators!
    I have some old Bolex lenses for standard 16mm e.g 10mm with 4.5mm asp heron adaptor…will they work ok?
    Bound to be cut off i guess but C mount Schneiders.
    Any advice much appreciated here across the Pond!
    You rock!

  9. Pingback: Plethora of Updates on the Digital Bolex Reminds Us That Good Things Come to Those Who Wait « No Film School

  10. Okay so they are set for F4 indoor use…..but I noticed in the Vimeo ‘More Kish Lens Test’ video that it was filmed outdoors on what looks like quite a sunny day.

    How?

    BTW I am loving the footage!!!!!

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