A Mamiya C Series Filter Holder

I have owned and used a Mamiya C Series twin lens reflex for many years and have been completely satisfied with it - except for one very inconvenient shortcoming. The inability to use filters that require 'previewing'. To use a polariser effectively - indeed at all - you have to be able to see the effect produced as you turn it, and the same requirement applies to grads and 'effects' filters. It is extremely difficult, if not impossible to use these filters with a TLR with the required degree of precision.

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.

TLR Holder 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. Three Point 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 :-

Mike Taylor
193 Tolworth Rise North
Tolworth
Surbiton
Surrey
KT5 9ET

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 .

Fitting the Holder

Place camera or lens on its back.
Slacken set screws at top and bottom of holder.
Place holder over front of lens, ensuring front elements are centred in the front aperture of the holder.
Tighten the set screws, top and bottom. The clamping plates are fitted with a rubber strip to assist with grip and to prevent marks on the lens barrel.
Do NOT overtighten the screws.
The thread inside is intended to fail if the screws are overtightened. This is not a design fault, but rather a safeguard for your lens.
Finally fit the Cokin P filter holder together with the filter.
Move the slide into position over the viewing lens and assess the effect you want. Prior to exposure slide the holder over the taking lens, being careful not to move the filter from the position you have selected.

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