IR/UV Filter or not?

[christo]

Hi all,

I'm just getting into modified webcam imaging and starting to accumulate the necessary equipment. I am looking for opinions on the necessity of using IR/UV filters when imaging. I've been looking around and some people argue that they are wholly necessary and some are of the opinion that they are maybe not so necessary. Also if I should get one any suggestions on which one in particular?

Cheers folks,

Chris

[Kaptain Klevtsov]

They are useful, but not absolutely necessary. If you don't have one its not going to stop you getting some kind of image of planets. If you are doing long exposure DSO stuff then I'd go for a Neodymium or CLS filter first. I never use an IR/UV block filter for DSOs, maybe I should?

There are other opinions to follow shortly, I'm sure, but if you have a camera, no filter, and a clear sky, go for it!

Kaptain Klevtsov

[mpeniak]

I use IR cut filter. It seems to improve an image. One possitive effect I have noticed is that the blue and red colour you get on the top and bottom of a picture is much less apparent and your final RGB allignments in Registax will be less required IMHO.

Martin

[geppetto]

Did a with/without test on mine a couple of years back

using M42 as a target.

With the filter in, the stars were much less bloated looking.

A definite improvement in the focus of objects.

Dont fully understand why, but it was proof that one is handy

to have

HTH

[centroid]

Chris

As I understand it, most CCDs are sensitive to IR, and if not filtered, it can affect to colour of the image produced. I'm not sure whether or not the also applies to CMOS sensors.

I have an IR filter fitted to both my SXVF-H9C, and DSI, but don't bother using them on the LPI or SPC900NC, as these are only using for Lunar/Planetary work.

Starlight Express, recommend that an IR filter is used with their SX cameras.

As for the make, you won't go far wrong with Baader, Lumicon or Astronomik.

Dave

[Helen]

That's interesteing Dave. I've got one for my webcam (on Bern's advice) but don't use it with the watec for DSOs. Would it help my DSOs??

Helen

[centroid]

Hi Helen

Most web-cams come with a 'cheapo' plastic IR filter fitted, so there is obviously some justification for that.

I'm sure the Watec is CCD based, and as such there may well be some benefit in using an IR blocking filter with it. The Watec is of course a mono camera, so there's no colour content to be affected, but it could well help to reduce 'star-bloat'. I'm only guessing here, as I'm no authority on the effects of IR on image sensors. Maybe someone else on here is, and can 'through some light' on the subject (sorry for the Pun .

On the LPI and SPC900NC, I just use a plain Bak-4 glass 'filter', to keep dirt and dust off of the sensor.

With my SXVF-H9C and it's predecessor, the MX7C, I'm convinced that my DSO results were better with the IR filter in-place, than without it.

Dave

[Helen]

Thanks Dave!