Current trends in stock photography, and in other fields, seem to favour the eye popping super saturated colours that are only obtainable by using a polariser, and being unable to produce these results made me feel disadvantaged, so with this in mind I set about designing and prototyping a filter holder specifically for Mamiya TLRs. The device is based upon the Cokin P System and makes use of two adaptors and their filter holder. I considered other 'system' filters, but at the end of the day settled on Cokin as their products are rugged, of good quality, are easily obtainable and in widespread usage by both amateur and professional photographers.
Basically all that is needed is a way of sliding the filter holder from in front of the viewing lens to in front of the taking lens, while keeping the filter in the position you have set it. Easy isn't it? Not so!
It took months of trial and error, six protoypes and much film before the device was exactly right.
The first version was a ' lets try it and see lash up' designed to fit only one lens, and very crude. It worked! Just. It kept falling off the lens, wouldn't seat properly and finally the hole I had cut got too big and wouldn't hold on the camera at all. I built another version using a different fitting system - that was much better. Then I found out that some of the lenses had a slightly smaller barrel diameter to others in the range. I was not about to build a whole family of these things so it had to be adjustable. And so it went on, solve one problem and up came another one ( it seemed that as the thing improved it lasted longer, and lasting longer threw up longer term difficulties).
Finally, I had a near perfect design. It is adjustable, doesn't slip, doesn't mark your equipment, allows access to all the camera controls, and actually does the job it's intended to do. viz.: allows you to position filters accurately over the lenses. I also think it looks O.K.
At the moment the holder is only available for Mamiya TLRs but a Rollei version is in the wings and I have also designed a fully adjustable holder for all lenses from 40mm to 73mm diameter lens barrels, for SLR's (medium format and 35mm) and some large format lenses. A requirement for this is that you MUST have 4mm of lens barrel showing when focused at infinity. Again this uses the Cokin P Series filter holder. You can build your own holder if you wish. Drawings and kits of parts are available. Drawings and kits come with full instructions. Only hand tools are needed to build your holder from a kit. Working from drawings is a little more complex and time consuming. If you are not a DIY person then completed holders are available directly from me.
For further details please write, enclosing an S.A.E., to :-
193 Tolworth Rise North
A patent application has been filed in respect of certain aspects of this device.
Thanks to the Cokin Technical staff at Johnson - Photopia
Cokin is a registered trade mark. Cokin products are imported and distributed by Johnson-Photopia .
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