Homebrewing A Soft Focus Lensgreenspun.com : LUSENET : Large format photography : One Thread
A prominent feature of the Imagon lenses are the perforated discs that mount in the lens to achieve a controlled degree of soft focus.
Can one approximate the behavior of the Imagon with homemade discs mounted in a filterholder? It would seem a simple matter to fabricate these discs from something opaque, perhaps even black cardboard.
Has anyone tried this? If anyone is familiar with the Imagon, where do the discs mount in the lens? Is it in front of the lens or in a special slot somewhere within the lens barrel?
-- Ed Balko (veggie@,onmouth.com), February 09, 2002
An Imagon functions as a soft focus (not out of focus) lens with or without the disks. The smaller the center hole in the disk used the sharper the effect.
Doing what you are suggesting won't give you the effect of the Imagon as the lens you will use begins as a sharp lens and does not have the inherent abberations built-in to the Imagon.
-- Bob Salomon (email@example.com), February 09, 2002.
Most soft focus lenses rely on uncorrected spherical abberation. This leads to the characteristic soft focus look - the typical chracteristic is seen in the highlights where the soft focus produces an impression of shimmering light. Obviously, varying the amount of spherical diffusion by restricting the rays to the central part of the lens (either by using the discs or by stopping down an aperture) will reduce the spherical abberations and make the image sharper. I would imagine that most simple lenses (such as diopters) would have quite some uncorrected spherical abberation and wouldbe worth explring. ope this helps, DJ.
-- N Dhananjay (firstname.lastname@example.org), February 09, 2002.
I read an article in Shutterbug a couple of years ago -- probably 3 or so -- about two close-up filters and inter-sleved toilet paper tubes to make your own. I've also read about someone who left his lens sitting up so it collected dust and never cleaned it. The little soft-focus filters don't seem to be satisfying.
You could also take one exposure, then shift the film back and do a second -- which is realy the theory of a soft foucs lens.
-- Dean Lastoria (email@example.com), February 10, 2002.
If you left your ap wide open and replaced it with a disc at the plane where the aperture would normally be, ie remove the rear group and figure out a way for that thing to stay in place, you would get varying effects with different lens formulae. I'd start with an old f4.5 anastigmat. Put a polaroid back on and have at it.
-- Jim Galli (firstname.lastname@example.org), February 11, 2002.
Sailwind HiSoft and ProSoft series of filters can simulate the Imagon effect quite well!
-- Paul Schilliger (email@example.com), February 12, 2002.
This reminds me of an idea I've been meaning to try out for ages. If you make the aperture of a lens out of numerous small holes, and I mean really small holes, then the diffraction effect will be the same as that of the individual tiny perforations, but the overall exposure is the same as using an aperture the size of the sum of the holes, if you follow. Soooo, I should be able to get soft-focus effects due to diffraction, but with reasonably short exposures.
All it takes now is the willpower to sit and puncture a bit of blackened foil with a neeedle a few hundred times over. Drop it into the waterhouse stop slot of a process lens, light the blue backing paper, and retire on the proceeds.
(OK, maybe the retiring bit is just wishful thinking). The results should be interesting though, don't you think?
On second thoughts, a bit of mesh material might have the same effect, but with less needlework involved.
-- Pete Andrews (firstname.lastname@example.org), February 12, 2002.
I know the common answer on this site (and it always bothers me) is "Buy New Gear", so i say this most hestantly, but: Buy a soft foucs lens -- I've done a lot of experimenting, and there ain't nothing like the real thing. Dean
-- Dean Lastoria (email@example.com), February 13, 2002.