Hydrogen-A astro filter for Daytime?

[Nate]

Went and bought a cheap Hydrogen A narrowband astrophotography filter, and thought I'd test daytime first. Don't have pics, but tested with a diffraction grating, and the

656nm is true, but there's also leaks past 900nm as my 940 torch was pretty bright walking around at night. Might be useful for astro but haven't tested yet.

 

Links to products used

https://www.amazon.com/gp/product/B0141U858I/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

 

https://www.3d-astro.com/  for the 1.25in filter clip in.

 

Canon 77D FS, EL Nikkor 80 metal enlarger for the deeper mounting as the filter sticks out too far for standard lenses

Not great time for photography the heat waves were crazy bad this morning. Car was moving on the highway.

 

1/200th, iso 200, f8   W/B was done on PTFE in camera.

Channel swap with red, as it looks better with a blue sky. Used Affinity Photo and darktable for processing raw

 

 

Here's right out of camera, with contrast and converted to jpeg

 

[colinbm]

Looks fantastic Nate

[Nate]

Thanks, I was quite surprised I got anything good during daylight. Might be totally different if it was actually narrowband at specified 656nm.

[Fandyus]

If only 80$ was cheap to me, there'd be a lot more gear on my shelf :)

nice post

[Andrea B.]

So this is basically a narrowband, red-pass filter? It would be interesting to see how the photo looks without any white balance. I think you can do that in Darktable. I'll go check.

 

The 3-D Astro gallery is amazing!

[Andrea B.]

Darktable > Darkroom > Base menu > White balance > Pencil (set WB to user modified) > Channel coefficients

Set all of R, G, and B to 1.0 to see the raw file with no white balance applied.

 

 

 

[Doug A]

Nate, these are super. Glad you thought to try this in daylight. 

Thanks for sharing,

Doug A

[Andy Perrin]

It’s basically an IR filter with a slice of red thrown in. Interesting. 

[Nate]

5 hours ago, Andrea B. said:

It would be interesting to see how the photo looks without any white balance

I think I did this right

 

WB set

[Nate]

@FandyusThat is considered cheap for astrophotography filters. The mount I want is around $1500, but that took a backseat when I discovered UV

 

[Cadmium]

I have one of those, Baader brand, and more expensive than the one you show.

I got it for solar photos, to show surface detail.

The wider the band, the lower the price. They have about 3 or more band widths, unfortunately my filter band width is not very narrow, so it doesn't really get the detail I wanted. They go  down to about 3nm band width or less? But those get a lot more more expensive.

I will have to try mine the way you have used yours sometime.

Thanks.

 

 

 

[Nate]

Nice @Cadmium . I bought one to get a wide field pic, probably an hour or so of Orion to see Barnard's Loop and other nebula, seems pretty dusty around there. Didn't get a chance this season, maybe next.

[Andrea B.]

Thanks, Nate, for the non-WB version.

It reads all reds. Mostly between 352° - 355° on the color wheel. So almost pure red. 

 

Kinda funny that the background hills covered with trees look gray. But it's because those are a low-saturation red running around 33% sat and 50% brightness. Call it very dull pink I suppose.