Hasselblad 63mm Diffusion Filter

[arthur_gottschalk]

I'm wondering. what the 63mm diffusion filter for the Hasselblad 50mm C lens and early SWC looks like compared to the Softars, which I don't really care for. Any experience with these?

[arthur_gottschalk]

After a little research (Freytag) I discovered that this filter appears to be similar to the Rolleisoft and older (uncoated)  Duto  filters, which utilize concentric rings moulded into them, designed to give a soft, halo-like effect. 

[orsetto]

Interesting topic, AG!

In all my years using Hasselblad, I've never before now come across any reference to an alternative soft focus filter pre-dating the Softars. But sure enough, upon checking Freytag's Hasselblad Way book per your post, there was the info on the "diffusion filters". Oddly, these aren't mentioned at all in the fraternal twin Hasselblad Manual by Ernst Wildi, and most starngely they aren't mentioned in Nodins comprehensive Compendium book!

This led me to comb thru my collection of old Hasselblad brochures and price lists. The earliest list I have is from 1961, which notes the "#50C Diffusion Filter" but has no reference to Softars. The 1971 price list adds the well known trio of Softars, drops the Bay 50 Diffusion, but adds the "Series 63 Diffusion DF1". My 1969 lens brochure indicates the same single 63 model, the 1970 brochure shows 63 DF1 and DF2, then the 1975 brochure drops back to just the 63 DF1. Curiously, all iterations of the Diffusion filter are consistently priced at half the cost of the similar Softar over the years: whether that was due to higher mfg cost of the Softars or proprietary price gouging is difficult to determine (the Hasselblad Diffusion filter seems to have been based the Rolleiflex Duto filters, which in turn are based on an apparently unpatented generic design).

The Softar design has completely dominated the soft focus filter category since it was introduced, so today it is incredibly difficult to find good image examples showing the different effect of the Diffusion/Duto (or even discussions of the difference). A little sleuthing did turn up a couple of examples and comments on Amazon, however: surprisingly, the Diffusion/Duto concentric filter has had a recent comeback of sorts and modern versions are offered by the likes of Hoya and Kenko.

The Diffusion/Duto is described as a relic of the chemical photography era, because the effect it was employed for only really worked in prints or magazine ads and doesn't fully come across with digital imaging. Apparently the concentric ring effect doesn't so much soften the image as force visual attention toward the central subject: it was most popular for studio product photography during the golden age of magazine ads. Hasselblad (or its studio users) seems to have decided the Diffusion/Duto was more useful for the 50mm, 60mm and SWC wide angle trio, hence its availability primarily in only Series 63 size. The effect is variable with aperture and diminishes considerably as you stop down, in contrast to the Softars which remain soft across the entire frame even when stopped down.

The current spike of interest in the concentric Diffusion/Duto design is coming mostly from digital astrophotographers, who've discovered these concentric filters have an "undocumented" ability to brighten stars at the edges of the frame (or some such: I forget exactly how they deploy it, but it helps with some tricky star fields that would otherwise get swallowed by some camera sensors).

Since this topic is unlikely to ever come up again in a newer thread, I thought it might be a good idea to post the relevant paragraph from Freytag below for anyone who might need the info in future:

 

Edited March 29 by orsetto

[arthur_gottschalk]

Thanks for this Orsetto!  I plan to use it on my 50mm Black Swan "C" lens but haven't had the chance as yet.