Playing with new filter wheel

[RobertI]

Just had a quick play indoors with the new filter wheel and LRGB filters plus Starlight Live multispectral. After afew false starts finally got a colour image from my Lodestar mono - a significant milestone for me! The multi-spectral feature is extremely quick and easy to use. Result below (red, blue and yellow cups) under tungsten light and a pretty good rendition of the original out of the box, no colour adjustments were made:

I then added a luminance exposure to all three channels and got the result below. Does this seem right? I was in a bit of a hurry at this point and wondering whether I was only viewing two channels in the output.

Rob

[Martin Meredith]

Hi Rob

On the face of it I'd say no, it doesn't look right, but I can't say I've ever tested mine indoors so difficult to say what the extra L effect will have. I will give it a test at some point. It's tricky to judge what one would expect (just as shining a brighter light on an object can sometimes play havoc with its colour). What is noticeable is that the right hand cup now seems overexposed in the second shot while it didn't in the first, which is odd given that you're using mean to stack. 

Anyway, congrats on the filter wheel and looking forward to seeing some pictures (of the filter wheel at least!). 

Martin

[ChrisLX200]

Looks more like a colour image from a DSLR after the IR filter was removed... ;-) You would also need to check the RGB ratios of your filters are really 1:1:1

ChrisH

[Astrojedi]

It seems redshifted... Blue->green. Consequence of an expanding universe...

On a more serious note... Luminance frames can cause all kinds of headaches and in this instance are throwing your color balance off due to uneven contribution. Strictly speaking Luminance frames are not really required and can potentially mess up the contrast and colors unless you have a LP filter in the chain.

I sometimes use a LP filter instead of a Luminance filter but you you will need one which is parfocal otherwise it is a real hassle.

[RobertI]

1 hour ago, Martin Meredith said:

Hi Rob

On the face of it I'd say no, it doesn't look right, but I can't say I've ever tested mine indoors so difficult to say what the extra L effect will have. I will give it a test at some point. It's tricky to judge what one would expect (just as shining a brighter light on an object can sometimes play havoc with its colour). What is noticeable is that the right hand cup now seems overexposed in the second shot while it didn't in the first, which is odd given that you're using mean to stack. 

Anyway, congrats on the filter wheel and looking forward to seeing some pictures (of the filter wheel at least!). 

Martin

Thanks for the interesting observations Martin, I'll give it another go tomorrow and see what happens. i havent played with many of the adjustments yet but it's all good education for the real thing. Will post if I get any further.

 

40 minutes ago, ChrisLX200 said:

Looks more like a colour image from a DSLR after the IR filter was removed... ;-) You would also need to check the RGB ratios of your filters are really 1:1:1

ChrisH

Chris,  I have purchased the Baader filters which appear to be 1:1:1 (at least according to the testimonial) - have I interpereted this correctly?

[RobertI]

10 minutes ago, Astrojedi said:

It seems redshifted... Blue->green. Consequence of an expanding universe...

On a more serious note... Luminance frames can cause all kinds of headaches and in this instance are throwing your color balance off due to uneven contribution. Strictly speaking Luminance frames are not really required and can potentially mess up the contrast and colors unless you have a LP filter in the chain.

I sometimes use a LP filter instead of a Luminance filter but you you will need one which is parfocal otherwise it is a real hassle.

Thanks Hiten, so basically my best bet initially might be to just do RGB and leave the L? 

[Astrojedi]

I would give it a try at night on a DSO first (the wavelength of incident light also matters - so that could also be why the luminance frame is throwing color off). In theory as long as your RGB filters are balanced you should be ok. In practice I have found that the skyglow especially if you are at a location like mine can cause color casts if your L filter does not cut out LP.

You can still image without luminance frames. Imaging will be slightly slower but otherwise no harm.