Which 'Astronomik 12nm H-alpha clip-in filter' for Canon 6D?

[clwonghk]

Hi all,

I have an astro-modified Canon 6D and is considering getting the Astronomik H-Alpha 12nm clip-in filter which allows me to capture more red emissions.

I shoot only widefield Milky Ways, no deep sky.

I am so confused because there are soooo many similar products out there when I google it, can someone kindly advise if this is the correct product for my Canon 6D? Thanks!

Astronomik H-alpha 12nm Clip-Filter EOS XL - XL-Clip Filter Canon EOS Full-Frame cameras - Clip-Filter

 

Also, I have come across this 'Optolong L-eNhance Tri-Band filter'. Is this available for full frame DSLRs like Canon 6D at all, and what's the difference between the 'Optolong L-eNhance Tri-Band' and 'Astronomik 12nm H-alpha filter'?

On the website it says the Optolong filter can isolate the H-Alpha, H-Beta, and Oxygen III nebula emission lines. Since both filters isolate the H-Alpha, do they basically do the same job? What makes the Astronomik 12nm HA filter 2-3 times more expensive? Am I missing something?

 

Thank you in advance for your responses!

Marco

[Elp]

You have to match the housing type to the aperture around your sensor. My canon ones for my 600d were more of a circle shape.

How wide are you imaging as sometimes you can adapt 2 inch filters to sit in front of your lenses instead and will be far more useful for future use and resale value. I'd estimate anything less than 35mm may not work with 2 inch filters up front but it depends how the front lens is housed.

The lenhance is effectively a Tri band filter as you've written above but note, not many targets emit hydrogen beta (it literally a handful). The bandpass specific ones may vary in price due to brand, and also a narrower bandpass will cost more as they block out more LP. The lenhance has quite a wide bandpass, the lextreme is tighter and more so the lultimate, the latter two are ha+o3 filters. You may also find the clip in filters cost more than the standard telescope ones.

[Elp]

I believe the camera still captures the ha without a filter, it's just the LP will swamp the signal but can normally be brought back with selective red saturation.

[michael.h.f.wilkinson]

Note that a filter does not just cut out the unwanted LP signal, it also cuts out the photon noise that comes with that unwanted signal. Your signal to noise ratio is going to be better for H-alpha emitting objects. One drawback is that you will effectively be using just the red pixels of your sensor. The green and blue will not receive much in the way of signal (this is why narrowband imaging is usually done with monochrome cameras). To avoid this, I would consider the Optolong L-eNhance or L-eXtreme and other multi-band filters, which also pass O-III, etc. This means more of your pixels will actually get some signal.

With the 6D you will need one of these rectangular "XL" clip filters, rather than the little round ones for the APS-C systems (like my old 550D). The Optolong filters are also available in such a format. I got this result with an Optolog L-eXtreme  filter with my Canon EOS 550D (modded)

[clwonghk]

56 minutes ago, michael.h.f.wilkinson said:

Note that a filter does not just cut out the unwanted LP signal, it also cuts out the photon noise that comes with that unwanted signal. Your signal to noise ratio is going to be better for H-alpha emitting objects. One drawback is that you will effectively be using just the red pixels of your sensor. The green and blue will not receive much in the way of signal (this is why narrowband imaging is usually done with monochrome cameras). To avoid this, I would consider the Optolong L-eNhance or L-eXtreme and other multi-band filters, which also pass O-III, etc. This means more of your pixels will actually get some signal.

With the 6D you will need one of these rectangular "XL" clip filters, rather than the little round ones for the APS-C systems (like my old 550D). The Optolong filters are also available in such a format. I got this result with an Optolog L-eXtreme  filter with my Canon EOS 550D (modded)

Thank you for your insightful reply. What I want to I want to do is to strengthen the red by isolating it with an HA filter, and then blend it with my milky way shots to achieve something like this: 

Would you recommend the Astronomik 12nm HA filter or the Optolong L-eNhance filter? Thank you.

[Elp]

As mentioned the lenhance will give better pixel utilisation mileage, but the lextreme will be much better (I've owned all three original optolongs before the ultimate came out).

With a HA you're only using 1/4 of your sensor with a colour camera, and as mentioned, your camera is already capturing the signal, you just need to selectively apply it (but it's difficult isolating the red ha specific regions without using a ha filter). If you want to do as per your example image maybe ha only filter then.

[TiffsAndAstro]

1 hour ago, clwonghk said:

Thank you for your insightful reply. What I want to I want to do is to strengthen the red by isolating it with an HA filter, and then blend it with my milky way shots to achieve something like this: 

Would you recommend the Astronomik 12nm HA filter or the Optolong L-eNhance filter? Thank you.

This image is amazing.

 

[michael.h.f.wilkinson]

I have the L-eXtreme  filter, not the H-a for my 550D. I do use H-alpha filters on my monochrome deep sky cameras, so it is difficult for me to say which would be better for your purpose. The red channel of the an RGB image obtained with an L-eXtreme filter will contain mainly H-alpha, with some S-II thrown in for good measure. It will also contain more continuum than when using an H-alpha filter. Whether that is a problem for your purpose is another matter entirely

[clwonghk]

16 hours ago, Elp said:

As mentioned the lenhance will give better pixel utilisation mileage, but the lextreme will be much better (I've owned all three original optolongs before the ultimate came out).

With a HA you're only using 1/4 of your sensor with a colour camera, and as mentioned, your camera is already capturing the signal, you just need to selectively apply it (but it's difficult isolating the red ha specific regions without using a ha filter). If you want to do as per your example image maybe ha only filter then.

Thank you very much! If that means both L-enhance and HA filters do the same job I may go with whichever better price then

[clwonghk]

1 hour ago, michael.h.f.wilkinson said:

I have the L-eXtreme  filter, not the H-a for my 550D. I do use H-alpha filters on my monochrome deep sky cameras, so it is difficult for me to say which would be better for your purpose. The red channel of the an RGB image obtained with an L-eXtreme filter will contain mainly H-alpha, with some S-II thrown in for good measure. It will also contain more continuum than when using an H-alpha filter. Whether that is a problem for your purpose is another matter entirely

Thank you Michael. With your experience with your L-extreme filter and H-alpha filter, would you say they both are able to deliver the same result, i.e. enhancing the red nebulae? 

[michael.h.f.wilkinson]

32 minutes ago, clwonghk said:

Thank you Michael. With your experience with your L-extreme filter and H-alpha filter, would you say they both are able to deliver the same result, i.e. enhancing the red nebulae? 

They both do, but the L-eXtreme will also capture other wavelengths than H-alpha, so the enhancement of H-alpha regions may be slightly lower. On th eplus side, you also get O-II and some H-beta signal in the blue and green channel of your image, which might be used to enhance the emission nebula in other ways. I haven't made a head-to-head comparison, however.