Finally bought myself a Modded DSLR! (Which Filter to buy?)

[smr]

Hi guys, 

I've finally just bought a modified Canon 600D. I'm really looking forward to imaging many Ha Emission Nebulae. 

I'd like to buy a new filter for this, which would be better to go for, the L-eNhance or the L-eXtreme? I have Bortle 5 (19.57 mag skies)

[vlaiv]

I would say L-eNhance unless you for any particular reason want to separate OIII and Hb lines, or rather eliminate Hb lines.

Main difference between the two filters is that L-eNhance captures both OIII and Hb in green and blue channels of your DSLR, while L-eXtreme captures only OIII.

You won't be able to separate OIII and Hb with L-eNhance, but it gathers more signal because of additional Hb (that is present in some nebulae). L-eXtreme passes less light pollution, but you are in 20 mag skies so difference will be minimal (even in heavier LP difference would be very small given band passes of both filters).

 

[smr]

47 minutes ago, vlaiv said:

I would say L-eNhance unless you for any particular reason want to separate OIII and Hb lines, or rather eliminate Hb lines.

Main difference between the two filters is that L-eNhance captures both OIII and Hb in green and blue channels of your DSLR, while L-eXtreme captures only OIII.

You won't be able to separate OIII and Hb with L-eNhance, but it gathers more signal because of additional Hb (that is present in some nebulae). L-eXtreme passes less light pollution, but you are in 20 mag skies so difference will be minimal (even in heavier LP difference would be very small given band passes of both filters).

 

Thanks vlaiv, I'll go for the L-eNhance. Just need to decide between the 2" Filter or the EOS-C Clip in. I guess I don't really have any fast lenses that I would use for Deep Sky Astrophotography at the moment but if I were to buy a fast f/2 Samyang or so then it would have to be the clip in... decisions...

[R1k]

Quick newbie question - where would the 2 inch filter fit in your imaging train? Assuming DSLR - field flattener - scope

 

thanks

[smr]

8 hours ago, R1k said:

Quick newbie question - where would the 2 inch filter fit in your imaging train? Assuming DSLR - field flattener - scope

 

thanks

With the Z73 the filter attaches to the field flattener.

[TerryMcK]

Some filters are directional and should be placed so the male thread goes towards the sensor and the female thread is to the sky. The field flattener on the ZS73 has its filter threads the “wrong” way around. When screwing the filter in you find that the female threads of the filter are facing the sensor.

I had to buy an adapter from Teleskope Express that turned the filter the correct way around. Much better than turning the glass around in the filter frame! The adapter is essentially an M48 threaded tube about 7mm long.

An M48 filter allows you to use it on purpose made astronomy cameras in the future too.

Edited July 23, 2020 by TerryMcK

[smr]

8 hours ago, TerryMcK said:

Some filters are directional and should be placed so the male thread goes towards the sensor and the female thread is to the sky. The field flattener on the ZS73 has its filter threads the “wrong” way around. When screwing the filter in you find that the female threads of the filter are facing the sensor.

I had to buy an adapter from Teleskope Express that turned the filter the correct way around. Much better than turning the glass around in the filter frame! The adapter is essentially an M48 threaded tube about 7mm long.

An M48 filter allows you to use it on purpose made astronomy cameras in the future too.

Thanks, I didn't know that - so the Filter is facing the wrong way then without the adapter? 

Could you please link to the adapter which you bought?

Edit - I have the non adjustable (first) version of the Field Flattener, and have screwed a basic 2" Light Pollution Filter into it before, was it the adjustable one you bought?

Edited July 23, 2020 by smr

[TerryMcK]

My IDAS D2 is directional as mentioned in the literature - this is due in small part to the anti reflectance coating. I did try it the wrong way around and got strange results. I don't think the Altair Tribander is though it too has anti reflectance coatings on.

The field flattener I have for the ZS73 is indeed the adjustable one the 73A. The thread for the 2" filter is on the rear of the flattener accessible once the tapered collar is removed.

 

Here is the link to the gender changer https://www.ebay.co.uk/itm/TS-Optics-M48-x-0-75-gender-changer-length-7-5mm-continuous-2-male-M48a-M48a/392024691344?hash=item5b467e1290:g:sYEAAOSw4A5Yo8v2

[smr]

Ah right that's interesting.  I'm not sure why they designed that flattener so that filters would be facing the wrong way. In the original flattener that I have the thread is inside the flattener and faces the right way.

[smr]

The Filter seems to fit in nicely.