Custom red filter on Voigtlander 15mm Heliar?

[jfujita]

Hi,

I recently purchased a Voigtlander 15mm heliar and I'm planning on using it on a desert shoot with ilford SFX. I need to use a dark red filter (25A) with Ilford SFX to get the high-contrast semi-IR effects that I want but the 15mm heliar does not have a standard filter thread.

I have decided to cut some lee lighting gels of approximately the same value of a 25A red filter into a custom filter for this lens.

I'm planning on using a sheet of lee 164 "flame red" lighting filter that I'm going to cut. I know that lighting filters are designed for use on light sources and I'm wondering if this will be suitable for use on a lens.

Also, I'm wondering if I should try to use this gel in the front of the lens or should I try to mount it on the rear.


Any suggestions or comments from those who have experience in this matter will be greatly appreciated.

 

[projectbluebird]

I have the same lens, and I've had similar ideas about suitable filters, but never actually done so. As I see it there are three problems with using theater gels as filters: Filter factors, mounting, and fragility (the gels I remember using as a techie were easily scratched, or dented.). Looking at my heliar, the easiest solution might be cutting a disk of gel to fit flush to the inside of the short built-in hood, but it will most certainly contact the front element. I can't think of any easy way to mount it behind the lens, but even if you could there's still the filter factor to think about. I seem to recall that the sample books listed the total light transmission as a %, as well as the color curves, but I don't know enough to turn this into a usable filter factor.

I wish you luck, and would be interested in the results, if any, of your experiments.

 

[Bob_McBob]

CameraQuest sells a 77mm filter adapter for the 12/5.6 that can apparently be adapted to the 15. It's a little steep at $59, but seems like just what you're looking for.

 

[mr_phillip]

I'm not sure that using lighting gels as filters would do much for your image quality – there's a reason that proper filters use optical glass and coatings after all.

One solution I've heard of, but not tried, is to use a Cokin A300 filter adapter. This little trickster was designed to allow folks to mount filters on digital compacts, but at least one fellow on this forum has used it successfully with the CV15mm. You might want to check out this thread...

BTW Ilford's own special SFX200 Cokin filter ought to fit in the Cokin A300 – might be just what you're looking for.

 

[mr_phillip]

BTW, a 25A red filter won't give you IR effects with SFX200 – with plain red filters SFX200 just looks the same as HP5+, only grainier. You need a proper near-opaque IR filter to get it to produce the IR effects (I use a Hoya R72).

 

[sienarot]

Ilford's Cokin filter fits the "P" series holders, which is larger than the "A" series holders. Cokin does make an R72 infrared filter in the "A" size though. Look for the A007 filter.

BTW, if you are interested in the A300, I have a bunch for sale </shameless plug>

 

[Fotohuis]

You can buy a 72mm filter adapter for the C.V. S-W Heliar 4,5/15mm . With a 72mm Heliopan RG715 filter you will have a nice wood effect with the SFX 200 or the Rollei IR 820/400 film:

72mm adapter on the Voigtländer.

"Moon hoarses" RG715 filter with Rollei IR 820/400. C.V. 15mm S-W-Heliar. E.I. 12 Dev. AM74/R.H.S. 1+9 7:00 Min. at 20 degrees C.

 

[mr_phillip]

Ooh, that looks like an interesting adaptor Fotohuis. Where would I find one?

 

[Fotohuis]

http://www.FotohuisRoVo.nl

On very special request, manually made by Dutch Hasselblad.
72mm filter size and a special perspex ring around the aperture scaling of the lens with a plastic lock.