LRGB Imaging.

[ribuck]

Hi All,

Just a quick question about LRGB Imaging, when doing the luminous (L) part of the image would you normally expect this to be IR Blocked ?

For example in the baader RGB Set with comes with IR block filter, so can i assume that this would be used as the Luminous channel ?

I have looked at some images, some show the L channel being IR blocked and others are not.

[steppenwolf]

I would be very tempted to use an IR blocker on your L channel to avoid light splatter.

[ribuck]

would i just use the clear IR blocker for the Luminous channel ? or do i need to buy a clear filter ?

[ngc2403]

I would be very tempted to use an IR blocker on your L channel to avoid light splatter.

IR Is you alot by the planetary images because it is not affected as much by seeing

[steppenwolf]

Just the IR filter is needed

[bern]

With a reflector and mono camera you could try using clear or no glass for the L (luminance) channel. The usual form though is to use an L filter, which is UV/IR block, but most IR blocks are OK. If you're using the Baader filters just remember you need the IR block inline all the time.

bern

[ribuck]

That's great least i know that i use the IR filter all the time now. One last thing, if i have the ir cut filter on my filterwheel nose, when i come to do my Luminous i'll turn the filterwheel to an empty slot on the filterwheel.

does this mean i will need to refocus, as i imagine the IR/Cut on the nose would not be parafocal with the RGB in the filter wheel

[bern]

Yep, you'll need to refocus.

bern

[ribuck]

Ok, sounds like i need to have the IR/Cut (clear) flter in the filter wheel for the luminous channel and maybe just have an IR blocking LP filter on the nose piece. something like an IDAS or CLS.

[bern]

The standard CLS filter is not IR blocking, as it was designed for visual use, but there is a CLS CCD filter which will be available shortly.

If you're putting an IR blocked LP filter in the nosepiece you could leave out the internal IR block.

Choose the LP filter according to your local conditions, if the local LP is strong and/or from high pressure fittings get a CLS otherwise consider the IDAS too.

bern

[ribuck]

Thanks Bern,

The main purpose of the LP filter is for ccd work. I'll give you a call at your shop to dicuss it, but this is what i have so far.

Atik filter wheel.

baader RGB Filters + IR Cut.

I was planning to buy a some form of LP filter for ccd work that cut's Ir and use on the nose piece of the filterwheel, then use the baader IR-Cut filter in the filter wheel for the Luminous channel whilst keeping it parafocal.