Atik I-R infrared UV blocking filter

[blinky]

Has anybody any advice on this? Atik I-R infrared UV blocking filter, looks like I may go for it, I want it to use with my unmodded ToUCam for planetry imaging as I currently dont have an IR filter and this ones seems to have IR and UV in one package!

Your thoughts would be appreciated

[mightymonoped]

Hi Blinky,

I've got one and it sits as a permanent fixture on my ToUcam. I have really pleased with it. You can check out my shots on http://www.garrity.plus.com

(unless it states IR Pass, pretty much everything on my site was shot with the Atik in place.

I believe that Saturn can benefit from not using the IR Block haven't tried it myself (as my scope's a little wee for real planetary stuff) but it's worth bearing in mind.

I would say "go for it"

Tony

[CELESCOPE]

Hi Blinky yes if you are using the Toucam u need the IR filter in mate ,

Cheers

Rog

[blinky]

Just missed it. It went for pennies above my max bid, Ho Hum better luck next time. BTW do I need an IR AND UV filter for my ToUCam or just an IR filter? I ask as it seems IR filters are cheaper and there are more of them...

[CELESCOPE]

IR will be ok Blinky

Rog

[blinky]

I am just wondering how necesery an IR cut filter is for imaging with CCD's? Does it improve the colour/contrast of a planet? I am just thinking that as the CCD is sensitive to IR light does this not increase the sensitivity of the camera overall as more 'light' will contribute to the overall image? or amI talking rubbush!

[michaelmorris]

Different wavelengths of light will naturally come to focus at different points because they are refracted by different amounts, depending upon their wavelength (i.e. colour). A lot of telescope design goes into trying to correct this problem, but preferentially in visible wavelengths. Thus it is entirely possible that an otherwise excellent telescope may not bring UV and IR 'light' into sharp focus at the same point as the visible parts of the spectrum. So, if your camera is sensitive to IR and/or UV (Most webcams and many CCDs are) the image may be blurred slightly by these out of focus elements within the picture. An IR/UV blocking filter removes light from outside the visible part of the spectrum and hence can lead to sharper images.

The other problem is one of colour balance. If a CCD camera or webcam is particularly sensitive at the red end of the spectrum (many are), then without an IR blocking filter, the image may be over-exposed at the red end of the spectrum. This is why tri-colour (RGB) CCD imaging uses special filters that also block IR wavelengths.

The Baader IR/UV blocking filter is particularly good because, unlike many IR blocking filters, it has a very steep cut off and doesn't significantly block light in hydrogen alpha wavelengths.

The somewhat confusing exception to this is using an IR pass filter. This only allows light in the extreme red and IR part of the spectrum through. This is useful for monochrome lunar imaging as it turns out that the IR end of the spectrum is less effected by atmospheric turbulence than the blue end, leading to a steadier image and hence heightened resolution. If you try using an IR filter in colour mode you just get a VERY red image. If you try using an IR pass filter remember to take off you IR blocking filter else you will see absolutely nothing!