Screw in filter holder for Olympus 7-14 2.8 pro lens

The Olympus 7-14 2.8 pro lens is a fantastic lens that has been ignored by any manufacturer to create an affordable screw in filter holder for it that has no compromises. Of the roughly 1/2 dozen solutions on the market for this lens almost all are for adapting the 100mm square filter systems to it, a couple for the 150mm square filter systems and only one that adapts the lens for screw in filters of 105mm, however this solution by STC still doesn't hit all my goals, no vignetting, and the smallest filter size available which I'm shooting for 95mm.

My primary focus is on travel photography, I hike a lot and must keep my photography kit extremely light, adopting 100mm square filters while the simplest solution and most readily available has two downfalls, one is cost and second is size and weight to bring the frame and filters along everyday. My main reason for a filter holder for this lens is a 10x neutral density filter so adopting all that kit just for one filter is not an option.

My goals are:

1) A screw in filter system

2) Smallest diameter filter possible

3) No vignetting

4) Light weight

5) Simple install and removal

6) Low cost

The idea I originally had was to form a filter holder out of Sugru and a filter step up ring and the step up ring would be the way to attach any filter I wanted. However I quickly realized that was the wrong way to go as the step up ring would result in having to ultimately use larger final filters than necessary. Instead it seemed better to buy a cheap clear filter of the same size as ultimately the final filters would be, form the filter holder to it, then break out the clear glass and then just screw in the final filter to it.

Sugru, is a clay like substance that hardens into a rubber like substance in 24 hours, so I started by ordering some from Amazon and trying it out as I'd never even used it before, but had read about it many years ago. It comes in different colors I chose black to lessen the chance of reflections. You can buy 8 packs of it for about $17.00, I purchased two 8 packs. Ultimately I used about 13 individual packs to make the holder

I started purchasing cheap clear filters on Amazon to test what size the filter needed to be in order to avoid vignetting. I started with a 85 which didn't work and found a 95mm appeared to be the smallest size that would not vignette. This was tested very rudimentarly by just holding the clear filter against the lens and shooting a couple of test frames against a light background

I made a paper ring of the same circumfrance as the lens and used this to mold on to get the proper final diameter of the ring as it needed to be wider at the filter and taper down to the lens.

Here is the result as it looked after curing the next morning.

A little sanding and clean up...

This first attempt was more about learning how to use Sugra and getting something that was functional and actually worked, while the results don't look like it was produced commercially, it hit the benchmarks of functionality for certain.

Next was to test shoot it... this frame shot at the white ceiling shows a pretty much vignette free image.

INITIAL RESULTS: Shooting at 7mm in the 4/3 camera format or 14mm 35mm camera equivilent

In my typically preferred wide format of 16:9 no vignetting

However, the full frame Raw version of the file shows I'm getting some slight vignetting....

Holder on lens, still haven't removed the glass from the clear filter yet...as I haven't decided whether I will now invest in a 3x neutral density filter in 95mm size, or do this all over again in 105mm size version.

The closest rival to my homemade filter holder is by STC. They show non-vignetted pictures on their website, however they are in the same jpeg format size as the first image, so I don't know if using their holder I can get non-vignetted raw files.

If anyone has the STC filter holder I would be very interested in knowing what the full frame raws or the 4:3 format looks like, if you're getting any vignetting or not.

Additionally the other negatives to the STC are:

1) More expensive

2) Must remove lens from camera to remove the STC filter holder

3) Has some user safety issues about how you remove it, by not removing the filter from the filter holder first or you risk scratching the lens.

4) Uses larger filters 105mm versus mine with 95mm.

Please comment.

If you've used Sugru before interested in your experiences, especially how durable this substance will turn out to be, your thoughts on the vignetting in the raw file versus the Jpeg format, any questions or comments or anything you can add to be helpful

mfinley wrote:

However, the full frame Raw version of the file shows I'm getting some slight vignetting....

The easy way to avoid it would be to use a thin gel filter behind the lens.

Rear-mounting a filter isn't without problems, but it is less to carry and easier to avoid vignetting. It could have issues with sensor reflections and thicker filters can cause aberrations, and there's also the issue that a rear-mounted filter gives the lens front no protection.

Atarijedi wrote:

Fotodiox makes the WonderPana, which fits on the 7-14mm, it, and the STC, are the only circular screw in filter holders that I know of.

The WonderPana is 145mm filter holder, Yow!

UPDATE

I made a final version with improvements from what I learned on the first one.

This one is now 105mm with zero vignetting at any focal length. Again I started with a clear filter, molded the Sugru to it, this time leaving a gap around the lens barrel that I filled with a foam strip which makes the holder nice and snug on the lens and light tight.

I streamlined this one, making it quite a bit shallower than the first one, cutting off all the excess length that wasn't necessary

1 inch thick

Firecrest 105mm 10 stop ND filter

With ND filter screwed on

View of how the filter hold sits on the lens

Nothing left to do now but shoot some long exposures at super wide angles!

thevideoguy wrote:

My apologies for bumping this old thread, but I recently got this lens myself without thinking about the use of ND filters and polarisers down the line and now I'm paying the price. I've been toying with the idea of getting the STC filter holder, but I wanted to know which one of your goals it didn't fulfil? My main concern is vignetting. Also, have you consider re-creating your makeshift mould for others who might be interested in commissioning you for it?

Vignetting... larger to carry around,  more expensive, must remove lens from camera to remove the STC filter holder, has some user safety issues about how you remove it, by not removing the filter from the filter holder first or you risk scratching the lens....

Don't think I'm too interested in making these for others, it's pretty simple as I've demonstrated. Don't be too intimidated, it's pretty simple to do yourself.

The Sugru holder works well, going on 6 months, has been traveling around the world...

Enzojz wrote:

The reason why threaded adapter can't be fully printed is it's impossible to print threads with SLS technology, the precision is not enough.

I doubt that very much. See below....

But you can design one by yourself and do some extra diy to archive it.

Actually, it's a piece of cake to do it on cheap extrusion-based (FFD) printers.

For example, here's my customizer script to make filter holders . The trick is that a standard metric thread has a 30-degree slope, which despite being tiny, sags enough to cause problems -- so, make the underside a 45-degree slope that self-supports. It's still fully metric compatible, but works every time even on $300 printers doing 0.25mm layers for 0.75mm pitch threads (e.g., a Wanhao I3).

I'd bet the same trick would also work with SLS, because I think the imprecision is really just minor dimensional variance where the sintering is/isn't supporting the structure... but I haven't tried it on an SLS. Don't have one handy... yet.