New to mono imaging filter advice

[Kyuzumaki]

Just wanted a bit of advice regarding mono imaging. I have a few filters that came with my second hand scope. They are all revelation filters I know these are not top quality but has anyone used these for imaging? I was looking at a light pollution filter found this on eBay 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F370861000046

im sure it’s not perfect but has anyone tried them or similar?

at some point in the future I do plan to buy good filters and make a filter wheel but before spending more I want to make the most of what I have unless it’s entirely futile to try

[KemalOz]

On 26.03.2018 at 13:38, Kyuzumaki said:

Just wanted a bit of advice regarding mono imaging. I have a few filters that came with my second hand scope. They are all revelation filters I know these are not top quality but has anyone used these for imaging? I was looking at a light pollution filter found this on eBay 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F370861000046

im sure it’s not perfect but has anyone tried them or similar?

at some point in the future I do plan to buy good filters and make a filter wheel but before spending more I want to make the most of what I have unless it’s entirely futile to try

that's not a LP filter, it is a moon filter.

And why do you need a LP filter for mono imaging? Is it for luminance? Do you already have narrowband filters or just RGB? Of course starting with what you have already in hand is the best option.

 

[Kyuzumaki]

I have the filters in that photo. Not sure what #8 or the ND one are useful for. All seem to be from the same set.

I found a different light pollution filter by SVBONY which seems to cut the correct frequencies. Someone on the web had one tested altgough it’s a bit more broad spectrum than the high end ones.

 

 

[KemalOz]

visual filters and imaging filters are different. It is hard to judge from these photos but they look like visual filters to me. Maybe you can ask the retailer who sells these filters to be certain.

 

Btw you don't need a LP filter if you are going to image mono. You should have narrowband filters first and then maybe you can use the LP filter as luminance. Or do you just want to get a black and white photo?

[carastro]

I just looked them up, the #56 filter is for planetary.  96 looks like a Moon filter.  I too am pretty sure these are observing filters.  

Carole 

[Kyuzumaki]

I have a lot of street lights nearby so the logic was simply to remove the sky glow which is prevalent in all my images. (Filter was only £15 so not much lost if it sucks)

They are all sold as observing filters. But I already own these  so thought they might do for a while. What’s the difference between observing and imaging filters except for cost?

[HunterHarling]

Imaging filters have anti reflective coatings to reduce halos.

[KemalOz]

2 hours ago, HunterHarling said:

Imaging filters have anti reflective coatings to reduce halos.

and light transmission is also better. they give more accurate color too. there is a reason why they cost more.

 

 

[ollypenrice]

4 hours ago, Kyuzumaki said:

I have a lot of street lights nearby so the logic was simply to remove the sky glow which is prevalent in all my images. (Filter was only £15 so not much lost if it sucks)

They are all sold as observing filters. But I already own these  so thought they might do for a while. What’s the difference between observing and imaging filters except for cost?

There are several differences. The bandpasses of a set of imaging RGB filters are designed to work together to produce a natural colour image in which colour balance is respected and good colour separation is still maximized. The idea is to get the right overall colour and have good colour contrast.

Visual filters are not intended to work together since you can't look through two or three at once! They are designed to increase contrast on specific targets in what becomes roughly monochromatic light.

The more expensive CCD filters are interferometric. They reflect those wavelengths which they seek to exclude. The cheaper CCD filters and (so far as I'm aware) the visual colour filters are absorption filters. I've used both for CCD imaging and, while the interferometric ones are certainly better (giving higher transparency and better colour separation) you can certainly work with less expensive absorption filters - but they should be imaging filters.

Olly