Full-Spec Modded DSLR, FILTER HELP NEEDED.

[LOL221]

Aloha Astrogang.
Yesterday i successfully Full Spectrum Modified my Nikon D3400 and instantly had a chance to try it out. The oiginal plan was to Ha mod it but i didnt have a filter to replace the stock one with... I kinda already knew a full-spec dslr is bad for AP.

I dont know what filter to put in to get rid of the IR star-bloat while keeping the cam more sensitive to the red glow of Ha, thats where i need your help. 
After doing some browsing (yeah i know i shouldve done that before modding the cam) i found this Multispectra Clip Filter and its Transmission Characteristics .
Is that the filter i need? And if its more than i need, would it benefit me in any way?  

It would fit my D3400 and is, at least in my opinion, a steal for that price.
A simple "Yes" or "No" is enough but i like detailed explanations too!

[tooth_dr]

A simple UV-IR filter -

https://www.firstlightoptics.com/uv-ir-filters/astronomik-ir-blocking-filter.html

 

[LOL221]

5 hours ago, tooth_dr said:

A simple UV-IR filter -

https://www.firstlightoptics.com/uv-ir-filters/astronomik-ir-blocking-filter.html

 

Thank you so much, but i cant find an Astronomik Clip filter that fits Nikon APS-C. Can you recommend any brands?

[michael8554]

The filter Tooth suggested would need to be fitted in the T2 to 1 1/4" adapter you use to connect the camera to the scope.

Michael

[LOL221]

22 hours ago, michael8554 said:

The filter Tooth suggested would need to be fitted in the T2 to 1 1/4" adapter you use to connect the camera to the scope.

Michael

So a Clip-in Multispectra filter for my D3400 would be better? Im not using my DSRL for daytime photography anyways.

[tooth_dr]

I wasn’t suggesting that particular filter, just an example for the type of filtration that would be useful.  UV-IR.

What scope is it for? Do you want to use it with lenses? How is the DSLR attached to the scope?

Edited March 26, 2020 by tooth_dr

[LOL221]

20 hours ago, tooth_dr said:

I wasn’t suggesting that particular filter, just an example for the type of filtration that would be useful.  UV-IR.

What scope is it for? Do you want to use it with lenses? How is the DSLR attached to the scope?

First of all, neither mount or scope are suited for AP but i got some impressive results for what they are.
The Scope is a Nexstar 102SLT on its stock AltAz mount. No lenses, except for barnards loop but thats it. Prime focus, T2-ring screwed to large end of eyepiece holder and then into the scope.
As stated, my original plan was to get rid of the stock filter and replace it with a filter that lets Ha through, BUT i dont want to do narrowband imaging only. Thats why i linked the STC Multispectra filter because it seems to do exactly what i need it to do.

[david_taurus83]

For normal imaging a simple IR/UV cut filter on the end of the 2" nosepiece will do the job OR a good light pollution filter. A good quality Ha filter will block out UV and IR anyway.

[LOL221]

The people in Facebook's Astrophotography groups told me something completely different.
Am i just too dumb to understand this?

I removed the ICF (aka the stock filter that comes with the camera, infront of the sensor) and now have to replace it. 
I do not want to do narrowband imaging.
I do not want to capture a single emission line on its own.
And again, would the STC MultiSpectra filter work?

All i need is a filter that blocks the invisible part of UV/IR but lets the Ha, Sii and Oiii emission lines through.
Is that what a UV/IR cut filter will do? Ha is part of IR so wouldnt a normal UV/IR cut filter just cut the Ha line off? 

[tooth_dr]

6 minutes ago, LOL221 said:

I removed the ICF (aka the stock filter that comes with the camera, infront of the sensor) and now have to replace it. 
I do not want to do narrowband imaging.
I do not want to capture a single emission line on its own.
And again, would the STC MultiSpectra filter work?

All i need is a filter that blocks the invisible part of UV/IR but lets the Ha, Sii and Oiii emission lines through.
Is that what a UV/IR cut filter will do? Ha is part of IR so wouldnt a normal UV/IR cut filter just cut the Ha line off? 

You are allowing all the light to get through using an UV-IR blocking filter, so it will allow Ha Sii and Oiii through, but also every other wavelength from 400-700nm.

Ha is not in the IR, it's 656.3nm, which falls within visible light and within the UVIR filter 400-700nm.

If you want to take broadband colour images of objects, then get a UVIR filter (or Light Pollution filter depending on your local environment ).  I havent used that filter, but it appears to be a strong LP filter.  Anyway it will work, but you will lose some data as it will be blocked by the filter.

Does that help you any?

[Thalestris24]

Hi LOL221

The multispectral filter you mentioned would do if that's the only one you can get to fit your camera. I don't have a Nikon but I think I've seen clip filters for them - Astronomik, STC? 

However, I think you'll struggle with your alt-az setup. You're going to be limited to ~30s exposures. I think you'll have to take a lot of 30s exposures...

Do post some of your images 

Louise

[david_taurus83]

The main benefit of clip filters is you can use them with some camera lenses. Are you going to use camera lenses? 2" mounted filters are far more versatile. More choice, can work with any camera, come up second hand, easier sold on if you fancy a change. Are you looking to do normal colour imaging? If so, as already pointed out, a UV/IR cut filter will reduce star bloat while letting through all the other wavelengths. If you have local light pollution then a good quality CLS-CCD filter will work as they also block out UV/IR. If you want to isolate narrowband wavelengths, then there are duo-band and tri-band filters that pass Ha, Oiii, Sii while blocking out most broadband wavelengths. Most of these are available as 2" mounted filters but choice is limited with clip filters.

[michael8554]

Be careful with cheap UV/IR filters, many start to roll off too soon, so start to cut the Ha. 

If they don't provide a transmission chart then avoid, and if they do check how it rolls off. 

Michael 

[LOL221]

On 30/03/2020 at 00:44, tooth_dr said:

You are allowing all the light to get through using an UV-IR blocking filter, so it will allow Ha Sii and Oiii through, but also every other wavelength from 400-700nm.

Ha is not in the IR, it's 656.3nm, which falls within visible light and within the UVIR filter 400-700nm.

If you want to take broadband colour images of objects, then get a UVIR filter (or Light Pollution filter depending on your local environment ).  I havent used that filter, but it appears to be a strong LP filter.  Anyway it will work, but you will lose some data as it will be blocked by the filter.

Does that help you any?

Yes, that helps massively. So Ha is not part of IR... I shouldnt ask the facebook groups anymore, or atleast confirm every word they say with reliable sources.
Yes i want to take Broadband color images, basically just like the stock camera would but with higher red sensitivity and no IR or UV bloat. 
So the Multispectra filter will work. Thanks a lot, i got it now. This is all very confusing to me, especially because im a complete beginner when it comes to modded cams.

[Thalestris24]

Hi again LOL221

You may also find this thread of interest

Louise

[LOL221]

On 30/03/2020 at 02:07, Thalestris24 said:

Hi LOL221

The multispectral filter you mentioned would do if that's the only one you can get to fit your camera. I don't have a Nikon but I think I've seen clip filters for them - Astronomik, STC? 

However, I think you'll struggle with your alt-az setup. You're going to be limited to ~30s exposures. I think you'll have to take a lot of 30s exposures...

Do post some of your images 

Louise

Its not the only one that fits my D3400, and yeah the filter is by STC, but the transmission chart seems to show exactly what i need the filter to do. I was acutally quite surprised that there are clip filter for the D3400 because last time i looked, there were none. My Alt-Az Setup actually isnt all that bad. Yes, with the 660mm focal lenght im limited to 30 seconds (+- 5 sec depending on conditions) but it works better than i thought it would. 
I will upload my images to Astrobin, will post the link here later since it takes a while.

[LOL221]

3 minutes ago, Thalestris24 said:

Hi again LOL221

You may also find this thread of interest

Louise

oh haha, i already posted in that thread. But my images there are through a completely non-tracking 8" Skywatcher. 

[LOL221]

On 30/03/2020 at 11:44, michael8554 said:

Be careful with cheap UV/IR filters, many start to roll off too soon, so start to cut the Ha. 

If they don't provide a transmission chart then avoid, and if they do check how it rolls off. 

Michael 

thats what i thought. Thats why im checking thrice on everything, cant afford to waste my already low balance.

[LOL221]

On 30/03/2020 at 02:07, Thalestris24 said:

Do post some of your images 

As requested, heres my Astrobin Gallery. https://www.astrobin.com/users/LOL221/ 
These are not all DSO's i shot yet, but i got so much data to process... I think ill need the next 2 months haha.