IR filter options

Ian,

I find glass filters easier to deal with than gels. As for the occasional cleaning of a filter, you can clean it the same way you would clean a lens.

Bjorn's website is the best source I've found so far on UV photography, but that is a field I haven't explored yet.

Filter prices increase rapidly with size. 49, 52 and 62mm are common sizes, so they are relatively cheap. Buy your filter for the lens with the biggest filter thread and use step down rings for lenses with smaller filter threads.

As for film, I'd suggest you try Kodak infrared black and white. With Kodak you will need to load and unload your film in complete darkness, so a changing bag will be necessary if you want to be able to change outdoors.

Hi, Ian,

Neither AF-3 or -4 swings out. The older and discontinued AF-1 (attaches to 52mm thread) and -2 (72mm thread) do. Both should be fairly easy to find.

The swing-away filter holder that accompanied UV-Nikkor 105/4.5 was nothing other than AF-1. What was special was the retaining ring (UR-2) which is just redundant if you don't need FF filter, which should be useless for digital UV photography anyway.

The size of the front thread of AF-1 is 60mm. I managed to find 60-62 step-up ring which is a little rare but now I can mount any threaded filters using more common step-up/-down rings.

Another way to attach/detach UV-pass filter is to use Nikon K2 and K3 rings. If you attach K3 onto 52mm thread of the lens (or step-up ring mounted onto the enlarger lens) and the UV-pass filter onto K2 ring, you can attach the filter via Nikon-F mount. This is as convenient as the Hasselblad filter system.

This Nikon K-ring system causes no vignetting even with Series-E 28/2.8 lens and U-360/BG40 filter combo on Nikon DSLRs.

If you use IR-pass filter for Nikon DX12-24 zoom, you may want to look at Lee filter holder with 77mm wide-angle mounting ring. Attaching and detaching of the holder onto the ring is very easy and convenient. With the Lee holder, you can use Cokin Z007 resin filter (equivalent to Wratten 89B).

I'm afraid I haven't tried my Lee system mentioned above with 12-24, but it seems to work.

Hope this could answer some of your questions.

Thanks very much, it does indeed answer a fair number of questions!

Do not consider using gel filters for IR, unless absolutely necessary (some fisheye and wide lenses only have a gel filter slot in the rear). They are way too delicate for reliable operation in the open. Plus when (not if) they get soiled, cleaning them is well-nigh impossible.

If you can mount a threaded collar (a step up/down ring suffices) to the front of a gel holder, then it can certainly act as a "swing" device. The AF-1 has 60mm front threads so is easy to press into service for this end, and I have a Pentax holder that can do the same.

The B+W O-92 is quite, but not similar to the R72, and its extra transmittance in deep red can easily blow the red channel. If you are serious about IR, consider using stronger filters such as the Tiffen/Wratten 87 or B+W O-93 (approx. 87C), or even the Hoya RM90.

Bjorn, thanks for the insight. The difficulty (near impossibility?) of cleaning the gel filters without creasing or otherwise damaging them was my primary concern. The second concern being creasing them in the process of mounting and removing. So, I guess I'll just be saving up for some glass filters!

My planned glass filter starting kit was going to be:

IR: Hoya RM72, B+W 093 UV: B+W 403 (UV pass) with B+W 489 (IR cut)

Hoya seems to no longer make UV bandpass filters (I can't find them for sale anywhere and they are not listed on their website). The Hoya glass can be found at Edmund optics. However according to http://msp.rmit.edu.au/Article_01/06.html it shouldn't be any better than any alternative except perhaps the UG-11x.

B+W 489 will largely destroy the UV transmittance of the 403 filter. Use the BG-38 or BG-40 instead. Or, drop any of these (incl. the 403) and use the Baader "Venus" to gain maximum IR suppression.

If I get the Venus filter, it seems to be available only in a 1.25 inch-diameter thread size. How did you mount it on a 52mm lens? Is 31.7mm (i.e. 1.25") close enough to 32mm to use a standard step-up ring? Maybe with some of that white non-stick plumbers' tape wrapped over the treads?

I have read sporadically and at various places online that Klaus at macrolenses.de will use the same glass and fabricate other sizes. Do you know anything about this?

Thanks so very much!

Ian

Baader only makes the "Venus" ("U") filter in 1.25", but that isn't as bad as you might think. Firslty, it helps keep the price quite affordable, and secondly, most lenses eligible for UV work are happy with even this small filter provided it is close to the front element. I have used the Venus on 28 and 35 mm lenses without any vignetting at all. Same goes for the Venus on my 63/3.5 EL-Nikkors and 105/4.5 UV-Nikkors, and the 138/4.5 Wollensak Graphic Raptar. I think it also did well on my 160/5.6 Fax-Nikkor, but memory may deceive me so I'll have to do a new check on that.

I made a bayonet-type mount for my Venus filters (3 of them) using an M42-F adapter plus the K3-ring on the lens itself, so adding or removing the filter is a breeze. Baader sells an M42 adapter for the Venus, by the way.

So, you're saying that you have very little problem with the Baader filter mounted on the front element of the lens. But, you have now combined it with a M42 Adaptor and a K3 ring and are bayonet mounting it on the rear element for ease of use. Is that correct?

Also, please excuse my ignorance, but, I am really having difficulty picturing the Baader Filter plus M42-F and K3 combination. I understand how bayonet mount filters work, but, I can't really visualize how these components go together exactly!

Any chance you could post a photo of your assembly? I know that's a lot to ask, though. So, if you don't have an image available, I'm sure I can figure it all out once I'm holding one of the filters in my hand.