I’ve extensively used my Pentax 6X7 and 67 cameras for many years and especially like their high speed lenses — 90mm f/2.8, 105mm f/2.4, 150mm f/2.8 and 165mm f/2.8. All these lenses, and some others as well, use a 67mm filter thread. And I find it very strange that Asahi had never released a universal hood for them.
Mamiya G2 bellows lens hood
But such a universal solution — G2 bellows lens hood — has been released by Mamiya for their line-up of lenses for RB67 and RZ67 cameras. Most Mamiya lenses use a 77mm filter thread. So, it is possible to use Mamiya’s bellows lens hood with almost all Pentax 67 lenses. It is very handy because it covers 90 – 200mm focal lengths. Why not carry only one hood for all your lenses?
As I’ve already said, a majority of Mamiya RB67 & RZ67 lenses have a 77mm filter thread. A mount adapter is usually included by default with the hood for this filter size. But Pentax 67 normal and telephoto (excl. 165mm f/4 LS and late 200mm f/4) lenses have a 67mm filter thread. It is not a big problem. I use a 67mm-to-77mm adapter made from two step-up rings that I’ve got as part of a big set of rings.
Two adapters allow me to mount the Mamiya G2 bellows hood on lenses with 67mm or 77mm filter threads. It also has a special filter slot to mount 3″ gelatin filters and a 360mm lens mask. Thus, the hood enables me to use the same filter for all lenses and, on top of that, to apply filters not to the entire frame, but rather partially, to create special visual effects. This is another bonus from Mamiya!
By default, focal lengths on the hood rack are labelled for Mamiya lenses. These marks are made with some tolerance in regard to real lenses. This means that if the hood is set at the 127 position and used with the f=90mm lens, it won’t vignette. Similarly, if you use the f=105mm lens and the hood set at the 127 position, no vignetting will occur even with a filter mounted on the frontal part of the lens.
I also use the hood with 135mm f/4 Macro and 165mm f/2.8 too! Albeit they both have built-in hoods, sometimes a better one is still required. This is especially true for 165mm f/2.8, whose hood doesn’t really prevent glare and lens flare from various light sources. A series of test shots proved that the Mamiya G2 bellows hood may be used even in the 180/250 position with 135mm f/4 Macro and in the 360 position (no mask installed) with 165mm f/2.8 wide open without vignetting.
Of course, it is compatible with some other lenses with the 77mm filter thread, with no additional adapter required. These are, for instance, late 200mm f/4 and 165mm f/4 with a leaf shutter. According to the Mamiya manual, it is also possible to use a 65mm wide angle lens. And I think it should work fine with any of 55mm f/4 lenses that have the 77mm filter thread. But a series of test shots should be carried out to check if vignetting occurs or not.
Its key disadvantage is that it is somewhat bulky and not very convenient for travelers. While traveling, I prefer to take a rubber folding hood with me. But Mamiya’s hood costs much less than the total price of original Pentax hoods for each lens.