ZWO EFW + Filters

[Figgis]

Dear All. 

               Up until now I have only been using a LP Filter for Imaging with my asi2600 with average results for Deep Sky.  So I have purchased an ASIEFW and a set of  3 Narrowband Filters to enhance my pics.  My question being would I keep my Light Polution fixed in my Stack somewhere, while I image with the Narrows in the wheel?   I should say the Camera is colour and the three NB ar O-III, H-Alpha & S-II.

Edited August 15, 2023 by Figgis
ommited words

[Budgie1]

57 minutes ago, Figgis said:

My question being would I keep my Light Polution fixed in my Stack somewhere, while I image with the Narrows in the wheel?

Depending on which narrowband filters you've got, they are likely to be blocking the same wavelengths as your LP filter. If you leave the LP filter in the image train you're effectively blocking those wavelengths twice. 

I would put the LP filter into the filterwheel and use it for broadband targets, like galaxies, to keep your options open.

[Paul2019]

This led me to an interesting question, as you didn’t mention if the camera is mono or colour. Can you use regular narrowband filters with a colour camera? Or are you limited to the duo, tri band filters such as l-enhance or l-ultimate. Sorry for the hijack 

[Figgis]

No no, fire away, this is all good knowledge

 

[Budgie1]

As I understand it (happy to be corrected by those more knowledgeable ) with a OSC camera you have the bayer matrix which is normally RGGB, so for every four pixels in the sensor, you have 1x Red, 2x Green & 1x Blue. 

If you use a narrowband filter, such as an Ha filter, the wavelengths which get to your sensor will only register on the Red pixels, so only 1 in 4 pixels are used. It also means you have to have 4x more integration time to get the same amount of data as you do with a mono sensor of the same size.

I'm sure it's much more complicated than that, but I think that's the basics.