Step-Down Ring on 90mm f/5.6 Super Angulon

[Jeremy]

I know, I'm a cheapskate, but I am wondering what loss I'll have by putting a 82-77mm step-down ring on my 90mm f/5.6 Super Angulon for when I need to use a filter. All of my other lenses have been standardized to 77mm filter rings so I have a set of filters in this size only. This would only be for use when I need a filter and will be using a 82mm hood on the lens when a filter isn't needed.

Is it possible to put a step-up ring on the back filter ring from whatever it is (I don't know) to 77mm and put my filters back there instead of on the front and just use the hood on the front?

 

[Donald Miller]

Jeremy, You will have mechanical vignetting. I don't know exactly how much or whether it will be bothersome for you. Only trying will tell.

 

[Jeremy]

With such a large image circle I think the vignetting wouldn't be too bothersome, but you're right Don, I'll have to give it a shot. When I get home I'll hold a 77mm filter over the front of the lens and see how much vignetting there is. I'm thinking mounting the filter on the back is going to be the best option if I can get a ring to go from whatever size is on the back to 77mm.

 

[naturephoto1]

Jeremy,

The filter size was one of the major reasons (as well as size and weight [and before I knew about the Nikon 90mm lens which is still lighter]) that I purchased my 90mm Rodenstock 90mm f6.8 Grandagon MC over 15 years ago. Though the lens does not have as much of an image circle, and is only a 6 element 4 group lens (rather than the 8 element in 4 group f 5.6 Super Angulon lens) it only has a 67mm filter thread. I have found my lens to be an exceptional performer. Additionally for my landscape work for 4" x 5" I found that it had adequate coverage. Also, like you I had standardized to 77mm filter size.

But, I would expect a step down ring on any of these lenses will in all likelihood suffer vignetting. The extent of the the loss will require some testing.

However, in the past I have used the Lee Filter system but for many applications is larger than I want. But I am now standardizing many of the filters for field work using the Cokin P size filter holder system (but not using the Cokin filters). Filters including polarizers, grad filters, etc. can be gotten from Lee or Singh Ray to fit the holder. In fact, Singh Ray sells an assortment of polarizing filters that fit directly into the Cokin P holder. And here is the kicker, an 82mm adapter ring is available to fit the P holder.

If you decided to use the Cokin P filter holder the only filters then that you might need in the 82mm filter size then might be a protection filter (your choice of UV, skylight, protection- if you use them) and a Center ND filter for light fall off.

If you used the Lee or the Cokin P size filters, once you had the filters, all that you would need would be the adapter rings for your lenses.

Rich