Samples of Infrared Star Trail photography?

Does anyone have any examples of star trail images shot using

infrared black and white film? Or even just pictures of stars, like

Astrophotography?<br><br>

I haven't seen anyone do this and logically it seems like it would

capture a lot more stars or possibly bring out parts of the milkyway

in the pictures.

I can't think why it would show any more stars than normal. And, since it tends to be a grainy film, it would quite likely show less than many films.

If you used infrared filters, you'd be blocking a lot of the light, and lose stars that way. If you didn't use any filters, you'd possibly have trouble with the focus shifts across the whole spectrum. Without filters, I really doubt you'd pick up any more stars than you would with TriX.

From what I've read of astrophotography, the main keys to bringing out more stars are very long exposures, using clock drive mechanisms, guiding scopes, etc., and using "hypered" film, whatever that is.

I recall reading on one website, a test of the reciprocity characteristics of some different films. Ilford SFX scored very low in that regard, and that would probably offset whatever gains the increased spectrum gained.

Grain size shouldn't be an issue as I'm planning on shooting 120 sized infrared film without a filter. As far as reprocicity failure, I haven't thought of that so I'll do some research. I was thinking of using Macophot 820c.<br>

With the issue of focus, I'll be shooting at infinity with the f-stop set to 5.6. I want to get a nice good shot, set for 1 or 2 hours exposure time.

<P>I doubt it'll make much difference, the stars that shine most in infrared are very faint and probably won't register at all on a short exposure with normal photographic lenses even with the fastest film.</P>

<P>But it's worth a try, without filters you'll get something anyway, though you'll probably see less difference than if you try IR film with your usual models.</P>

<P>To expand on the faintness of IR stars - stars that send out most energy in IR are very cold and send out much less energy than warmer stars like the Sun even in IR. A hot blue star sends out more red light than a colder red star. A red dwarf like our Sun sends out more IR than a star so cold it's mostly IR.</P>

<P>In star trail photography, you get mostly the brightest stars anyway and IR should make little difference.</P>

<P>There are differences as you can see <A HREF="http://www.eso.org/outreach/press-rel/pr-1999/phot-29-99.html">here</A>, but most of the stars in those images are very faint to begin with and won't register on a normal star trail photo. The best way to get more stars with normal photographic equipment is with faster film and lenses.</P>

I think it would be more impressive for nebula (nebulae? nebulas?) and other objects with lots of red light. Tech Pan shows a lot more detail of the Orion nebula than normal B&W film because of it's extended red sensitivity. Unfortunately, that means a guided exposure.

Has anyone ever hypered HIE?

I've done the ir night shots of the stars and sky. With out a red filter there was too much sky glow from city lights. With red filter there were normal star trails.

mark in dallas