View Full Version : Market Need for Filter/Compendium Solution for Wide Angle Lenses

Larry Huppert
5-Aug-2000, 11:09
Problem Statement:

Mounting filters on LF wide angle lenses has always been problematic. Screw-on filters will tend to vignette or be extremely expensive in larger sizes. 100mm x 100mm/150mm square/rectangular filters provide a more universal and cost effec tive solution across a set of lenses, however they can also present unique probl ems when used with WA lenses. The use of a center filter which is often require d with WA lenses only compounds the problem. For example, Lee makes a fairly ex pensive adapter (FK100) designed specifically for the Schneider 72 & 90 SA XL le nses when used without a center filter. Indeed, this holder does the job. Howe ver, when a CF is used on these lenses, there isn't a non-vignetting solution av ailable when using 100mm filters. In fact, the filter element is larger than th e filter. To me, investing in a separate set of even larger filters (e.g. Cokin X-Pro) is something to be avoided if at all possible. The other part of the eq uation is the mounting of an effective compendium on WA lenses, both with and wi thout filters. Here again Lee Filters brought to market a wide angle lens hood with a self support bellows. Because Lee pretty much adapted components from ot her products in making this compendium, the end result is not really tuned for L F use where lenses get very wide and/or significant movements are possible. My experience has shown that if no filters are used, the hood can be somewhat helpf ul. If filters are required, it is almost impossible to keep from vignetting af ter fitting the hood. For my purposes, the hood with built-in slot(s) wasn't us eful because I'm often using grad filters or polarizers where independent rotati on of the filters relative to the hood orientation is required. If a CF is used , there is no solution.

These issues have made me brainstorm alternate filter holder/compendium design c oncepts geared towards the problems LF shooters face. I've made some crude prot otypes of a filter holder design and shot some film to verify their ability to n ot vignette. At this point, I have confidence that the holder design will work with two 100mm square/rectangular filters fitted over a 47XL, 58XL and 72XL thro ugh their complete movement range with a CF. Although I don't own one, it shoul d also work with the 90XL. I'd guess that three or more filters would be possib le with the 72XL and 90XL and maybe even the 58XL (although this is probably rig ht on the edge). I also have preliminary concepts for a design which would allo w independent rotation of multiple filters and a lens hood which would work with this range of lenses, CF's and 100mm filters.

Certainly more design/prototyping is necessary before it's ready for even a prof essionally built model made out of the actual materials I had in mind. I will n o doubt see some version of this concept through to a model for my personal use. However, I'm curious in understanding if a wide enough market exists for a bet ter holder/compendium to justify addressing this as a small business opportunity . This second step is a very large step because of the implications it brings ( more professional mechanical design, tooling, design for easy manufacturing, US and select international patent(s), cost, price, sales channels, distribution, . ..). Another approach I've though of is to setup a low volume custom manufactur er with this design who could then build them on a per order basis.

I'd be interested in a discussion of what I've presented here towards the goal o f critiquing the product requirements, and understanding if there is enough of a market to proceed with this idea in a commercial way. What price would someone would be willing to pay for such an item?

Some of the open product requirement issues in my mind are:

* Importance of independent rotation of multiple filters (e.g. using multiple gr ads or a grad and a polarizer).

* Importance of integrating a compendium into the design.

Bob Salomon
5-Aug-2000, 14:32
Linhof compendiums for the Technika, TK, M679 and Kardan cameras take 4x4" filters, 95 or 105mm screw in filters and cropping masks.

It sounds like you are re-inventing one.

Larry Huppert
5-Aug-2000, 15:43

Could you describe the Linhof lens hood/filter holder in more detail. Certainly if Linhof has solved this problem in total (or close enough), there is no need for me to devote further effort. I'd rather be taking pictures than inventing camera gear.

I've only seen a small picture of the TK version of it in the B&H sourcebook, and we all know that book has an error or omission here and there. Is there more information about this item on the HP Marketing website or the Linhof site? Does it work on any brand of LF camera (I use an Arca Swiss F and Canham DLC), or does it have to be a Linhof? How does it mount on your cameras? Maybe it could be adapted to another camera through some type of custom bracket. How many filters does it hold? Does it only handle gels or can you also insert Lee polyester filters which are in frames? Can you use 4x6 resin grad filters in this device? Do the filters rotate independent of the hood? Will it work with all the lenses I mentioned through their entire range of movements? What is the functional difference between the Professional Compendium Hood (001929) @ $1,024.95 (B&H) and the version for the Technikardan (001931) @ $538.95? How do these products "knock down" for packing and transit? I must say at first glance, these Linhof products appear to be the only ones designed with LF capabilities in mind.

Bob Salomon
5-Aug-2000, 22:33
Call me next week and I can answer your questions. It only fits linhof as you need special adapters.

I can mail you more detailed descriptions.

neil poulsen
6-Aug-2000, 02:22
I have an Arca-Swiss F with a home made reducing lensboard on the front. It's been contrived so that one can use Graphlex (non-view) lens boards. Since the Arca Swiss board stays on the camera (I change only the smaller lens boards), I was able to mount a Calumet Zenophon 4" filter on the Arca Swiss lensboard. I use rear mounted, Kodak, 4" gel filters. This meets my filtering needs for all my lenses. (65mm SA through 14" Dagor, including a 90mm f5.6 SA.) Note, that I do not use center filters, which probably are best used on the front anyway.

I'm wondering if the same type of solution would work for you if you got the 110mm Arca Swiss reducing lensboard? I know it would work with the Arca Swiss/Linhof Technika reducing lens board.

We had quite a lively discussion on this site about the viability of using rear mounted filters. The end result was that gel filters are thin enough that the don't affect the focus by all that much. Even if they do, you can check the focus with the filter in place. Also, filters tend to generate more flare if mounted on the front than on the rear.

Larry Huppert
6-Aug-2000, 13:02

Since I use both a A-S and DLC, I was looking for a solution which could work with both. Rear mounted filters on the DLC, especially with wide angle lenses is just not practical. Also, since my most often used filters are ND grads & polarizer, rear mounting on any camera isn't likely to work too well. I looked at the Zenophon holder a while back, and thought it impractical for my lenses. The range in rear element size/depth is too great. I'd always be readjusting the holder.