September 26, 2014

A Set of Low Cost/High-Performance Cine Primes Just Hit the Market, but There's a Catch

Digital Bolex Kish Lenses
High performance cinema lenses never come cheap. However, when you add fixed apertures to the equation, even the lowest budget filmmakers can afford world-class optical quality.

I'm talking, of course, about the Kish cinema lenses designed specifically for the Digital Bolex D16. Released to the public last week, the Kish primes, which come in 10mm, 18mm, and 38mm focal lengths, are legitimately one of a kind in a market saturated with various types of stills and cinema lenses. They come with a C-Mount -- which is easily adapted to many other mounting options -- and they can cover sensor areas between 16mm and Micro 4/3 .

What sets the lenses apart from the crowd, however, is the fact that they come with an f/4 fixed-aperture, which not only keeps manufacturing costs way down, but also ensures that these lenses are always in the "sweet spot" in terms of optical performance. Add to that the fact that these lenses are less than $400 apiece, and less than $1000 for the full set of three, and it's clear that the Kish lenses are an interesting and noteworthy proposition for low-budget filmmakers, especially those shooting on cameras like the GH4 and BMPCC.

If you're wondering how the image quality of the Kish/Bolex primes stacks up against sets of cinema lenses costing more than a new car, Joe and Elle over at Digital Bolex recently tested their lenses against four of the biggest names in cinema glass manufacturing. In the image below, you'll see one shot from each of the seven lenses tested - three of which are the Kish primes, and one of which is a zoom tested at two different focal lengths - all under the same lighting conditions. The only variables in this test are lens choice and focal length. Click the image for the full resolution.

Kish/Digital Bolex Cinema Lens Comparison
Credit: Digital Bolex

On Monday, the fine folks at Digital Bolex will reveal which lenses are which in this blind test, and we'll be able to see how the Kish primes compare to their much more expensive counterparts.

For anybody worrying that fixed aperture lenses would make it practically impossible to shoot in tough lighting conditions, the Digital Bolex team made a quick video to showcase not only that it is possible, but also that their new lenses handle it extremely well. This was, of course, shot with the Digital Bolex D16 and a combination of all three of the Kish lenses.

Of course, fixed apertures mean that exposing properly with these lenses is a function of ISO and lighting manipulation (or maybe shutter speed if absolutely need be). For some cinematographers, this won't be much of an issue since many higher-end narrative productions are shot at one or two aperture values, while the lighting is changed to vary the exposure. Shooters who are working in environments with controlled lighting will want to give these lenses a good long look because the optical quality is unmatched, especially for the price.

For run and gun shooters who need to change exposures on the fly, however, these lenses won't make much sense, as the boost in optical quality won't make up for the extreme drop in practicality.

Ultimately, the Kish lenses are a unique and affordable option for filmmakers using m4/3 and smaller formats. They're definitely not practical for all users, but for folks interested in high optical performance at a reasonable price, they're certainly worth a look. They're on sale now on the Digital Bolex site. Additionally, if you'd like to learn more about the production of the piece above, head on over to the Digital Bolex blog    

Your Comment

40 Comments

Oh, just imagine the pain of working with these!

All the DPs out there -- the producers be like: but we got these Kish cinema lenses! [Facepalm]

September 26, 2014 at 8:13PM

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Alex Zakrividoroga
Director
3913

All you'd need is some http://www.xumeadapters.com/ and a full set of NDs! I think they'd be fine to work with. Magnets!

I think this is a really cool alternative lens set. Not for everybody, but interesting. Personally I enjoy the DOF of 5.6/8, but that's just me.

September 26, 2014 at 8:28PM

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Zack Wallnau
Cinematographer & Tinkerer
699

what pain is that? keeping a set aperture, and thus a set look, throughout your video?

September 29, 2014 at 1:59AM

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John Morse
Producer + Director
2442

WHY IS IT SO DIFFICULT FOR THESE PEOPLE TO HAVE GOOD DP'S MAKE TEST VIDEOS FOR THEM?!

September 26, 2014 at 8:21PM

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Steven Bailey
Writer/Director/Composer
759

They need to find their John Brawley.

September 26, 2014 at 8:30PM

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Zack Wallnau
Cinematographer & Tinkerer
699

They hire their friends instead of professionals.

October 26, 2014 at 8:20PM

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Jeremy Parsons
Director of Photography / 1st Assistant Camera / Crane Tech
178

How do I get these to mount on my Gh4?

September 26, 2014 at 8:35PM

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You will need a C-Mount to Micro 4/3 adapter, and that's it!

September 26, 2014 at 8:58PM

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Rob Hardy
Founder of Filmmaker Freedom
4627

I have a BMPCC. Is there a specific adapter for the camera? Because I have a C-Mount to MFT and there is vignetting in all the lenses I have (even the tele ones).

September 26, 2014 at 9:54PM

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That's really interesting. That should only be happening if the lenses you're using don't have an image circle large enough to cover the BMPCC sensor. With that said, there are a bunch of C-Mount lenses out there that aren't large enough to cover that sensor, usually the cheaper ones made for closed-circuit security cameras and things like that.

Here's a good list of lenses that lenses that work with the BMPCC and lenses that don't.

http://www.eoshd.com/comments/topic/2513-blackmagic-pocket-cinema-camera...

September 26, 2014 at 11:45PM, Edited September 26, 11:45PM

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Rob Hardy
Founder of Filmmaker Freedom
4627

Thanks!

September 27, 2014 at 6:20PM

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One can smear a jar of Vaseline on a Nikon kit lens and get the same resolution as Digital Bolex ... and, for a lot less too ...

September 26, 2014 at 11:23PM

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Dan Leo
220

That comment makes absolutely no sense whatsoever.

September 26, 2014 at 11:46PM

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Rob Hardy
Founder of Filmmaker Freedom
4627

I hope they make a version of these lenses with a functional aperture at a higher price point.

September 27, 2014 at 1:50AM

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Ed Jones
281

If you can't get an exposure at F4 with the low-light sensitivity of today's digital cameras, you're doing something wrong.

October 26, 2014 at 8:22PM, Edited October 26, 8:22PM

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Jeremy Parsons
Director of Photography / 1st Assistant Camera / Crane Tech
178

Why bother posting something like this?

September 27, 2014 at 4:40AM, Edited September 27, 4:40AM

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Charlie K
1353

It's literally just a matter of plopping down 75-100 bucks on a Fader filter and you have a sick set of cinema primes. OR, Jeebus forbid, you actually have to put down your 5d and light a scene for once. I don't get all the backlash.

September 27, 2014 at 1:50AM

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Mike Stewart
Director-ish of phontograpy
81

I am 100% with you there. I wish people were as enamored with lighting skill as they are with "flavor of the month" gear.

October 30, 2014 at 3:21PM

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Jeremy Parsons
Director of Photography / 1st Assistant Camera / Crane Tech
178

"If you're wondering how the image quality of the Kish/Bolex primes stacks up against sets of cinema lenses costing more than a new car..."

"...three of which are the Kish primes, and one of which is a zoom tested at two different focal lengths - all under the same lighting conditions."

You should edit this, Kish has in no way compared these to "cinema lenses costing more than a new car" if they compare primes and zooms.

Comparing apples to oranges does not sell apples.

A second note:

(PLEASE correct me if I'm wrong, I'm always learning and thus I signed up for your excellent site!)

Are these lenses 10, 18, and 38mm focal lengths expressed in D16 format with a 1.0x crop factor, or are they expressed in 35mm with a 2.69x crop factor?

If expressed in terms of 35mm focal lengths, that would make each lens a static f10.76, which is unacceptable for the work I do, maybe useful to....someone.

Again, I admit I may be wrong.

September 27, 2014 at 2:26AM

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Kam Nield
180

The aperture will remain at f/4, as aperture values don’t change based on frame size.

I think you’re mixing up focal length terminology, as focal length isn’t based on frame size it’s based on the measurements of the lens no matter what frame size it’s designed for, so you can’t have a lens “expressed in terms of 35mm focal lengths.” What you can have is a lens expressed in 35mm equivalent crop factors, which I don’t think these are, based on the sample footage they’ve shown.

September 27, 2014 at 3:36AM

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Ryan Toyota
Graphic Designer / Typographer / Video Editor
1176

You're right, Aperture values don't change on frame size, but my current Rokinon lenses at T1.5 are completely different depths of field on a 5d and on my GH4. So I'm asking if the same lens then put on a D16 is going to have an even WIDER depth of field?

i.e. the same lens at T1.5 on a 5D is X depth of field, which looks like "T1.5" to me, as I began on a FF. That lens on a GH4 (in 4k: 2.2x) has the equivalent depth of field of "T3.3" if matched on a FF, and then again on a D16 (2.69x) would have the equivalent depth of field of around an T4 setting on a FF.

So same question as before, but I understand the aperture size is a ratio of focal length to aperture diameter now. What I should have asked is this:

Is f4 on a D16 equivalent depth of field to f10.76 on a FF camera?

How would one ever use a D16 camera to achieve the shallow depth of field of even an f2.8 on a FF?

September 27, 2014 at 1:07PM, Edited September 27, 1:07PM

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Kam Nield
180

Also, you're right - focal lengths are expressed independently, the term I should have used is:

Are these expressed in 35mm equivalent "Angle of View" or 16mm equivalent "Angle of View."

Again, as per my other comment, everyone knows a 10mm on a 2.2x crop will "look" like (or have the equivalent "Angle of View") of a 22mm on a FF camera taking the same shot.

So again I ask, what's the "Angle of View" on this 10mm Kish when applied to a D16 camera? its certainly not 10mm FF equivalent, and I bet it'ss be a 26.9mm equivalent - which would mean my other comment that the depth of field will vastly increase is true as well once the crop factor is applied to the depth of field (f4 x 2.69).

September 27, 2014 at 1:12PM

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Kam Nield
180

Hello Kam, I'm not an expert DP or anything, but I can answer some of your questions and give you some pointers. Forget about frame size equivalencies. Equivalencies are slightly useful only as a rough guideline if you are experienced in one frame size and not another, but they also make it easy to confuse yourself if you rely too much on them. Instead, look at what you have at hand and the effects and results that you are seeing with your eyes. Also, in terms of pure cinematography, equivalency to full frame 35mm still frames (135) is useless, because the vast majority of cinema cameras and film shoots operate with motion picture 35mm, which is already around a 1.5x crop compared to full frame. See how this can get confusing?

A 10mm lens marked as such on the barrel, is 10mm no matter which frame size it is attached to, and will have the same characteristics on any frame size as well. The only thing that changes is the crop factor, which literally means that if you take that 10mm lens and take a photo at f/4, *at the same focal distance* (this is important), the only difference will be how much of the frame you see. In other words, if you had the same photo taken with the same lens and all the same exact settings (aperture, focal distance, etc) on full frame, Super 35, Super 16, Micro 4/3, what have you, all side-by-side to each other, and then took scissors to those stills to crop them all to the same size, you should see the exact same depth of field, foreground to background relationship, and brightness (with some variation due to different camera makers having different brightness at different ISOs, etc - if you used the same film stock in these different frame sizes the brigthness should be exactly the same).

The likely reason why I'm guessing you saw different DOF from the same lens on two different frame sizes is that you moved the cameras to match the framing (which you hint at by asking about field of view). As soon as you move the camera in relation to the subject, therefore changing the focal distance, you change the depth of field characteristics as well.

So finally, *IF you want to keep the same framing*, a 10mm lens will have different depth of field on different frame sizes, but only because the focal distance changed, not because the lens behaves differently or anything like that.

You may have already known most of this, but it doesn't hurt to repeat it and reinforce it (it helped me), and maybe it answered some of your questions as well, or may help you figure it out.

September 27, 2014 at 2:17PM

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Shen
339

This is confusing, the article (scroll down to Depth of Field) is where I did my research, and the question originally rose from switching from my trusty but soft Canon 6D to my new GH4 and hearing "f2 on the gh4 is more like f5.6 on the 6D in terms of depth of field"

http://www.cambridgeincolour.com/tutorials/digital-camera-sensor-size.htm

When I use the included calculator, the result is skewed because I DO NOT mean that I adjust my focal length to give each camera the same Angle of View in this test, I'm proposing a Canon 6D and GH4 side by side with the same manual lens set to the same settings (aside from camera settings). However the result is the calculation I provided abov, that if I wanted the equivelant depth of field on both camers (as if I was matching A cam to B cam) I would need to set the 6D to f3.2 and the GH4 to f1.4 (I used T1.5 above, sorry).

"As an example calculation, if one wanted to reproduce the same perspective and depth of field on a full frame sensor as that attained using a 10 mm lens at f/11 on a camera with a 1.6X crop factor, one would need to use a 16 mm lens and an aperture of roughly f/18. Alternatively, if one used a 50 mm f/1.4 lens on a full frame sensor, this would produce a depth of field so shallow it would require an aperture of 0.9 on a camera with a 1.6X crop factor — not possible with consumer lenses!"

September 27, 2014 at 4:28PM

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Kam Nield
180

As per the above quote, these lenses are say, 10mm f4.

To match the depth of field/f stop on a 10mm f4 on a GH4 I would need to set the 6D to 22mm and f10.76.

September 27, 2014 at 4:34PM

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Kam Nield
180

Kam there are two separate things you are talking about.
1st. Angle of view. Which is a factor of the mm of the lens and the capture / sensor size.
2nd. Depth of field. Which is a factor of the mm of the lens and the f stop.
These are independent.
A 10mm lens meant for full frame and a 10mm lens meant for 16mm will create the exact same image on a 16mm camera. They will also create the exact same image on a full frame camera, but the lens intended for 16mm will have a strong vignette, but the center of the lens where there is image will be exactly the same.
Those same two lenses will also have the exact same depth of field at the same f stop. Depth of field does not change based on sensor size. It's like a law of physics. You can figure out depth of field without even knowing the brand or format the lens is intended for.
Your quote above says "same perspective" instead of angle of view, but basically they are saying if you use a different mm lens to compensate for a different size sensor.
For our test we were comparing lenses intended for S35 with our lenses which were made for S16 and M43, but because the D16 has a S16 sized sensor these lenses looked the same.
Hope that's helpful.

September 29, 2014 at 4:13AM

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Joe, it is helpful, but it seems this Dpreview article and the wikipedia page on Depth of field disagree with you that:

"Those same two lenses will also have the exact same depth of field at the same f stop. Depth of field does not change based on sensor size."

From wikipedia:

Same focal length for both formats:
Many small-format digital SLR camera systems allow using many of the same lenses on both full-frame and “cropped format” cameras. If, for the same focal length setting, the subject distance is adjusted to provide the same field of view at the subject, at the same f-number and final-image size, the smaller format has greater DOF, as with the “same picture” comparison above. If pictures are taken from the same distance using the same f-number, same focal length, and the final images are the same size, the smaller format has less DOF. If pictures taken from the same subject distance using the same focal length, are given the same enlargement, both final images will have the same DOF. The pictures from the two formats will differ because of the different angles of view. If the larger format is cropped to the captured area of the smaller format, the final images will have the same angle of view, have been given the same enlargement, and have the same DOF.

From dpreview:

The blur disc size b is approximately equal to (please refer to the DoF Wikipedia article):

b = f ·ms / N = (f ·w2) / (N ·w1),

in which

f is the focal length (the actual focal length, not the 35mm equivalent),
N is the aperture or f-number,
*******w2 is the sensor width,*******
w1 is the subject height in portrait orientation or picture width in landscape orientation and
ms = w2/w1 is the subject magnification of the lens.
Please note, that the equation above is only valid, if the background is sufficiently distant from the subject.

The absolute value of b does not tell much by itself, when comparing cameras with different sensor sizes. If we however compare b to the sensor size w2 we can estimate how big the blur disc size is compared to the total picture height (please refer to the photo above) and thus come to a definition of the strength of the background blur B:

B = b / w2

September 29, 2014 at 6:49PM, Edited September 29, 6:49PM

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Kam Nield
180

Kam, I think you are over-complicating this. I don't have the energy right now to work through the mathematical formula from the dpreview article which I feel is an unnecessary exercise, but it appears that the wikipedia article is agreeing with us. The case where they are saying that the DOF will vary is if everything else is equal but you enlarge the cropped image to be the same size as the non-cropped image. Bingo, you've just changed a material (albeit minor) variable that would affect the apparent depth of field. However, in video/film, you generally don't have any control over the size of the image that the viewer watches, so there's no point in worrying about that.

Let's take this to the simplest, most basic form to understand what is happening: let's say you take a simple magnifying glass (Sherlock Holmes type), which is about the simplest lens you could possibly try, other than a pinhole or a drop of water (but those would also work), and in a dark room with a window, project the image of the window on an opposite wall in the room. The lens has to be pretty close to the wall in order for the image to be in focus (BTW, the image will be upside down). That distance to the wall is effectively your focal length. Keep the lens at that exact distance while you draw a full-frame 35mm sized frame around the image on the wall. Now draw a Super 35mm sized frame within the FF one, Now repeat with a 16mm sized one, and then repeat with whatever other format you want (large format still camera perhaps?).

Do you think that any of the characteristics (DOF, brightness, etc, except crop size) of the image projected by the magnifying glass will be any different within the various frame sizes?

September 29, 2014 at 9:05PM

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Shen
339

Kam, the Wikipedia article says the exact same thing I am saying...

"If, for the same focal length setting, the subject distance is adjusted to provide the same field of view at the subject, at the same f-number and final-image size, the smaller format has greater DOF, as with the “same picture” comparison above.

Or in other words, if you move your subject closer to the camera to get the same framing your depth of field will change. Of course it will, as you get closer to the camera depth of field work radically different than far away. True of all lenses regardless of format.

"If pictures taken from the same subject distance using the same focal length, are given the same enlargement, both final images will have the same DOF."
This is exactly what I said.

"The pictures from the two formats will differ because of the different angles of view. If the larger format is cropped to the captured area of the smaller format, the final images will have the same angle of view, have been given the same enlargement, and have the same DOF."
This is EXACTLY what I said. :)

September 30, 2014 at 6:33AM

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Also did you see our video with our S16 lenses looking very very similar to much more expensive S35 lenses?
https://vimeo.com/107516024
The depth of field is nearly identical, cause the fstop is the same and the mm of the lens is very close.

September 30, 2014 at 6:34AM

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OMG!!! Who set up the lighting for this???

September 27, 2014 at 10:16AM

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I did, we only had the lights that Hotrod cameras sells in house to use, which were small LEDs. I probably should have brought bigger lights with me.

September 29, 2014 at 4:15AM

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I wish they had setup the same pose and shot size for a lens comparison test. but honestly the back ground is so dark, un detailed and no chip chart it's hard to call this a test at all.

I guess if anything they can say the kish lens's can blend with the others, but they have little miperical data to back that up.

September 27, 2014 at 11:33AM, Edited September 27, 11:33AM

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David Sharp
Video Editor, Cinematographer, Teacher
377

This was really intended to look at character of the lens, sharpness, color, and how they treated skin.
We had a very limited amount of time and no area for a formal setup.
Hopefully more formal tests can be done in the future.

September 29, 2014 at 4:17AM

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Shouldn't watched that short video. #facepalm

September 27, 2014 at 1:54PM

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Tommy Plesky
Director / D.P / Editor
1738

Digital Bolex ? Ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha...

No, really: Ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha-ha !

September 27, 2014 at 2:36PM, Edited September 27, 2:36PM

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Ahhhmm.. i'll pass

September 28, 2014 at 2:44AM

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Wentworth Kelly
Director/DP/Colorist/Drone Op
2472

and the award for worst cinematography on a camera/lens commercial goes to...

September 28, 2014 at 3:30PM

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Fernando Mamede
director/dp
162

I really like the look of f4 with these lenses. The depth of field is shallow enough to bring focus, but is deep enough to still make out details of what's far away. It's nice.

September 29, 2014 at 2:29PM

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David S.
3100

I know this is an old thread now, but anyone see the video?
http://vimeo.com/107516024

October 1, 2014 at 3:16PM, Edited October 1, 3:16PM

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