Bayonet Mounts

by Paul Gates on 12 June 2011

All Rollei TLRs, from the 1937 Automat onwards, were fitted with the well known double bayonet lens accessory mounts to accommodate filters, lens hoods, Proxars etc. These admirable fittings suffer from one minor disadvantage. It is that, when using the standard Rollei lens hoods without an accompanying filter, an appreciable amount of the bright metal bayonet mount remains visible between the front lens element and the inside of the hood. This may seem to be a trifling point and not worth bothering about. Yet, the fact is that any bright polished surface, in close proximity to the front element of the lens, can cause trouble through the reflection and scatter of non image-forming light, leading to either degradation of shadow contrast or actual flare spots.

1) 2.8C with standard Bay. 3 hood. Bright metal mount remains visible

2) 2.8C with adapted Bay.1 hood. More effective hooding

I was fortunate enough to obtain a beautiful example of a Rollei Bayonet III hood, from David Morgan through the recent club Rollei auction, after several years of searching for this item. On fitting it to the camera, I was dismayed to note the amount of bright metal bayonet which remained exposed (see illustration 1). By utilizing a spare Bayonet III to 49mm adaptor (non Rollei) and “Aralditing” into the front of this, a spare Bayonet I lens hood (also non-Rollei, and of mainly plastic construction), I was able to fit this to the inner bayonet. The improved shielding of the front lens element can be seen in illustration 2. There is no trace of corner cut-off at any aperture.

3) MXV with standard Bay.1 hood. Too much bright mount still visible

4) Addition of blackened Bay.1 filter mount MPP, gives improved hooding

For my Rollei 3.5 MXV (Bayonet I) a simpler solution proved almost equally effective. An old M.P.P. Bayonet I filter mount proved to be of sufficiently generous proportions to cover the offending bright bayonet parts, so was matt black painted, and fits the inner bayonet, allowing the standard Rollei bayonet hood to fit over the outer bayonet fitting. (Illustrations 3 & 4). If a similarly wide bayonet III filter mount could be found, obviously the same dodge would have served for the Rolleiflex 2.8C also, thus saving the Heath Robinson bodgings. None of the Bayonnet III filters to which I have had access, however have had enough metal in them to cover the offending areas. Illustration 5 shows the two items referred to above.

5) Matt blackened M.P.P. filter mount and adapted Bay.III to 49mm adapter for 2.8C as described in text.

 

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