DIY Hack: Add a 3-Stop ND Filter to Super Curved Fisheye Lenses

The Rokinon 8mm f/2.8 lens is one of the best options for photographers wanting to get in on the super-wide-angle action with as little of an investment as possible.

One problem with this lens, however — and it’s the same with most fisheye lenses — is the curved front element. With such a dramatic curve, the use of filters on such a lens is almost impossible… almost.


The team over at CheesyCam has figured out a creative DIY workaround that allows them to attach a 3-stop ND filter to the Rokinon 8mm.

The application is “we wish we’d thought of this first” kind of simple: by using a 3404 gel from the Rosco Cinegel sample book and some blue tack, the CheesyCam team was able to mount the gel on the rear element of the lens, rather than the front, reduce the amount of light hitting the sensor by three stops with minimal tradeoff in terms of sharpness.


The hack itself is about as simple as they come, assuming you have the supplies on hand, so there’s no reason not to give it a shot if this is a problem you’ve run into in the past. And if you do try it out, let us know how it turns out for you!

(via DIY Photography)

  • Richard Polhill

    I have an old reflector lens which comes with a set of rear-mounting ND filters. These could well be usefully repurposed for this task with a little bit of tape.

  • OtterMatt

    This… this is genius. I’m having a hard time coming to grips with just how simple that solution was.

  • 3Horn

    Or Rokinon could follow Nikon’s example, and include a gel holder on the mount side of the lens.

  • innovatology

    Please stop this madness and remove this post (or at least include a warning). If used with a DSLR and the filter comes loose it will destroy your mirror!

  • Pickle

    If anybody is dumb enough to try this, I hope they don’t try to send their camera to Nikon and ask for warranty repair when their mirror is destroyed. Just send the bill to this guy and Petapixel since they thought it was a good idea to post this nonsense.

  • perkabrod

    I don’t understand, why not stop down aperture instead?

  • MickO

    Yeah guys, I hear that replacement mirrors for that GH4 are nearly impossible to find… *cough*

  • MickO

    You use this in addition to stopping down. to go beyond the minimum aperture of your lens to be able to extend exposure time to longer lengths for creative purposes.

  • CheesyCam

    Maybe you should pay attention at 1:21 when it’s specifically stated for Micro Four Thirds (no mirror – no DSLR).

  • Gannon Burgett

    Seriously. I was sent this by DL to write about and my jaw hit the floor with “why didn’t I think of that?!” when I first watched it.

  • Gannon Burgett

    If you watched the video, you’ll realize at 1:21 that he specifically states this should only be done with mirrors bodies.

  • OtterMatt

    I’ve got a whole pallet of spare mirror bearings I could sell people. Also, a bridge in New York.

  • Lambert Schlumpf

    I am sure that some of the Russian manufacturers has some fish-eye lens that they sell with rear mounting filters, they actually sell their lens with 3 filters included.
    It’s not actually genius. It’s like putting a welding glass or something in front of the lens of your compact camera

  • Lambert Schlumpf


  • Gannon Burgett

    Thank you. I upgraded to the OS X Yosemite beta, so I’m still trying to get it to “learn” all of the words that autocorrect things are wrong.

  • Dover

    I have been doing this for years on my Nikon cameras with no problem. Stop hyperventilating.

  • CheesyCam

    Aside from long exposures, If you stop down, you lose that shallow depth of field look which is sometimes desired. By blocking out light you can open up the aperture without overexposing.