Kowa 16H: flares and vignettes?

[highres]

I own the Kowa 16H, which I have recently received and tested with both a Red Epic, a BMCC and a set of Nikon Ai-S lenses. I found that the amount of barrel reflection on heavy flares caused a very strong yellow vignette. I thought it was my particular Kowa, but then I see the same on several Kowa B&H shots.
I have now seen this on all sorts of light from sun light to LED to sodium vapor to fluorescent, from medium taking lenses to tele end. I also hear it is common on other anamorphics.

 

Is this a known issue, is there anything that can be done about it? Does it happen more to some lenses than others or is it inherent to the design of the anamorphic adapter? It does not seem to happen on an Optex lens I've borrowed.

I've spoken to two lens technicians who say it is either the design or the lack of blacking on the edges of the front element (?)

 

I would want to use my Kowa but find the usefulness limited with these vignettes occurring anytime it flares.

One thing that comes to mind is to try and add a vignette of my own in post to hide the yellow vignette, but may look to obvious. Will need to do some testing with it.

 

I will shoot some examples with my lens today as I don't want to offend anyone else by posting their samples.

 

Would like to get some feedback from people if they have seen this happen and if they have any solutions?

 

One other forum member mentioned he got this with his anamorphic, and he could reduce (but not eliminate) the vignette with a mattebox. 

 

 

[JohnBarlow]

Set your scope free!

 

 

Back in the day, scopes were mounted on cine cameras and projectors on an adjustable sting so you could set the optimal scope-lens distance.

 

If you find the gap is too big use a rubber lens hood as filler.

[Bioskop.Inc]

Yep internal lens flare is a problem with the Kowa & I think John is right about the distance - could this be to do with its original application & the camera/projector/lens combo it was meant for?  

I found the Helios 44-2 58mm pretty much solved this problem & Alan (aka Redstan) has always said that simple recipe lenses work best!

However, i found that this flare mainly presented itself with outdoor shooting (sun) & not really indoors (lights).

 

It does take sometime to get used to an anamorphic lens - it isn't like a spherical lens & you need to allow yourself time to understand/decipher its peculiarities.

Don't dismiss the Kowa, it is a fantastic lens - but you'll need to experiment with taking lenses to find the perfect match. 

 

Another thing to bear in mind is that a lot of people have found that using longer focal length lenses produce the best results with anamorphics.

 

Also, some people really like this effect - i'm like you, it just pissed me off!

[tony wilson]

i have quite a few kowa and i say send it back to the ebay seller the sample i saw is bad it maybe can be repaired. buying a rough lens for 60 dollars and doing a diy job is one thing spending over 500 and getting flawed possibly messed with optic is another. it is not like this lens is that rare try a kowa bell howell.

that design was a compromise as it started as a projection then they made a version with shorter focal length internal cylindrical optics for camera.

it then became for projection and camera.

depending on the taking lens you do get quite a bit of barrel distortion. the movie anamorphics kowa did used a little more distance between cylindrical and also bigger size optics they give a nice flat field. each anamorphic was calibrated and designed matched to one focal length spherical lens.

the customer focus of kowa with the original design of the 8z was very much a 16mm and super 8 projection optic that could also be used with camera filming well. you will see even with high end anamorphics slight mismatch can occur check the sun flare lens halo. very slight amounts on edges at 3 secs in. http://vimeo.com/13863937

 

 

[JohnBarlow]

Simple solution No 2, requires some Blue Peter skills :)

 

First study the image below,

 

 

Compare the front of this Zeiss with the front glass in Kowas, Sankors , Mollers blah blah.

 

Figured it out yet?

 

Now the good folks at Carl's place in Jena knew a thing or two about optics....

 

What you need to do is cut out a hole in a piece of black cardboard using a compass and sharpie to make an aperture mask. Tape off the sides with some gaffer tape until you find the best point where the reflections disappear.

 

 

I really ought to get paid for telling y'all this....    :P

 

and if someone decides to start making these - remember you owe me.

[tony wilson]

zeiss really knew nothing about anamorphics like cooke they came to the party late.

those anamorphics where made by moller with a zeiss logo.

many other companies used that recipe it comes from hypergonar by chretien.

 

zeiss clearly are one of the legends of optics but a lot was taking other people concepts and making them better.

i have various zeiss labelled optics that where made by isco.

my guess was that they left most of it to moller maybe had some input on the coatings but even then mollers coatings are very zeiss like.

below is a vintage french lens 

 

http://www.flickr.com/photos/34211301@N00/8336906516/in/photostream/

[JohnBarlow]

That Dyaliscope will be very sharp once setup properly, as used on the old turret cams like Mitchell, Arriflex, Cameflex

 

see here

 

http://www.widescreenmuseum.com/widescreen/dyaliscope_lenses.pdf

[highres]

Thanks for all the input everyone! ok so I did some comparison tests with the Optex and the Kowa 16H, the latter of course looking much sharper, but the Optex easier to use.

The Kowa did not flare that much, in fact. I was trying to get the vignette to happen in run and gun shooting, but it didn't happen even when aiming straight at head lights etc. Will put up a comparison vid in a while once i have some time to edit. But leaning towards keeping the Kowa, as the picture is really pretty :) Now i just need some front filter clamps for both lenses!