C-Thread IR (UV) Filters

[Macavity]

C-Thread IR (UV) Filters. I have been looking for one for quite a while now!

But maybe the following would also be suitable for B&W Video as well?

http://www.firstlightoptics.com/uv-ir-filters/celestron-skyris-ir-block-filter.html

At the moment I use a Baader UV/IR on the END of the nosepiece, but often

I have occasion to swap extensions, filters etc. and dust bunnies get in!

I envisage this to replace one of the default 5mm C-thread spacer rings. It

can then stay permanently in place close to the chip, while I swap stuff? 

[Tinker1947]

I think the C-Thread extension uses the 1.25 Filters, FLO will know....

[Dom543]

Great find!

I have been looking for some way to put filters on my Lodestar without the use of a 1.25" nosepiece. When using photo lenses, the space between the lens and the camera is very limited. A nosepiece eats up all that space leaving none for the filter(s).

It is difficult to see on the photo, if the telescope side thread is a C-thread or a 1.25" filter thread. But either way would be good. If it's a filter thread, then a 1.25" barrel extension could be used instead of a nosepiece, if needed. Or a couple of empty 1.25" filter enclosure rings. (SurplusShed.com sells those for cheap.)

Please let us know, if you find out which thread is on the telescope side.

Thank you for posting this,

--Dom

[JamesF]

Great find!

I have been looking for some way to put filters on my Lodestar without the use of a 1.25" nosepiece. When using photo lenses, the space between the lens and the camera is very limited. A nosepiece eats up all that space leaving none for the filter(s).

It is difficult to see on the photo, if the telescope side thread is a C-thread or a 1.25" filter thread. But either way would be good. If it's a filter thread, then a 1.25" barrel extension could be used instead of a nosepiece, if needed. Or a couple of empty 1.25" filter enclosure rings. (SurplusShed.com sells those for cheap.)

Please let us know, if you find out which thread is on the telescope side.

Thank you for posting this,

--Dom

I imagine both the threads will be C threads as the supplied nosepiece will then still fit to the front of the camera.

It would perhaps be useful if they did clear optical flat too (perhaps they do and I couldn't see it).

James

[Dom543]

I got one of these filters from AgenaAstro.com.

It has C-threads on both sides. It is 5mm thick so that it can also be used as a CS-to-C-mount adapter.

Thank you for calling our attention to the existence of this filter.

--Dom

[f15p5]

Thanks for the heads up,been looking for this. Just ordered one off amazon for $29.00.

[Macavity]

Thanks people.

Heheh - I haven't yet got around (found funds!) to buy one myself.

Thanks for the above information re. threads and thickness tho'!

It seems IDEAL for my purpose too. But I suppose I do still wonder...

It is simply an Infra-Red filter with (e.g., unlike Baader) no UV block.

I sense (know) Video Chip response extends sigificantly into the IR.

Thus it seems wise to control (filter) this. But what of extraneous UV?

Chip response seems to be falling quickly below 400nm, so maybe

we don't care. I seem to remember refractors (glass!) stops UV...