Solar Imaging "Path Forward" Advice Needed.... - Forums

Topic starter

Oct 29, 2023 · Edited: Oct 29, 2023

I have been into wildlife photography for about 8 years and just got into astrophotography a few months ago. I have been lurking around here recently and just joined yesterday. I have enjoyed viewing everyone's images and seeing the equipment used to capture them.

My primary interest is deep sky astrophotography (galaxies and nebulae currently) and I have been using a Canon R5 and R7 along with an RF 100 F2.8 and RF 100-500 lenses. So far, I am pleased with the results I am getting but realize the next step forward would be getting an actual telescope and eventually a monochrome, cooled astro camera.

I just photographed the October Annular Eclipse, and I am very happy with my results using a "white-light" baader astrosolar PHOTO film. I recently stumbled across the dedicated hydrogen alpha telescopes, and I was blown away by the detail you can capture on the sun.

I am toying with the idea of shooting the April 8th eclipse in H-alpha. My goal is to get a composite image of all phases of the eclipse with totality in the middle. Like this image I captured during the annular eclipse (I know I will have to shoot totality with separate camera/lens).

Full resolution image here: Annular Eclipse from Mountain Home, Texas - 10/14/23 - (Horizontal Composition) (mdees88) - Full resolution | AstroBin

My dilemma is trying to decide the best route to do this.

If I already had a refractor telescope, I think my best option would be to buy a daystar quark. Then I could use it on multiple telescopes in the future for both wide angle and more close-up imaging.

Since I do not own a telescope, I am leaning towards buying a Lunt 40 or Lunt 50 solar scope. From my research, I have read that monochrome sensors work best with h-alpha filters so I will also likely need a new camera. It seems most all use the lucky imaging technique, and take short videos, then stack the best frames to create an image.

So here is what I have come up with so far....

Option 1: Buy a Lunt 40 or 50 ($1000-1300) and a dedicated planetary camera ($300-500)

- which would you recommend, the 40 or the 50?
- is double stacking necessary for a not extremely zoomed in image like the one above?
- Since the images are not close-ups, will my Canon R7 provide enough surface detail, or should I still use a monochrome camera?
- It seems like newton rings and bright/dark areas are issues you run into with solar imaging. Would picking a camera with a larger sensor (so the sun is smaller in the frame) be better? Perhaps then I could place the sun at certain point inside the frame, where thel "distortions" are minimal. I guess the tradeoff is less resolution/detail in the sun itself. For instance, with a ZWO ASI178MM the sun will fill the majority of the frame, but with a ZWO ASI174MM the sun will be much smaller in the frame.

Option 2: By a Daytstar quark ($1300), a new refractor telescope ($700-1000), and a dedicated planetary camera ($300-500)

- Ideally, I would rather not spend this much money right now, but I could swing it. This method costs more but I would end up with a telescope I can use for deep sky imaging as well as solar imaging. One reason I would like a new telescope for night imaging is so I can image over multiple nights to collect more data. With the zoom lenses, I can only image one night because of the specific focal length I set the lens to is not accurately repeatable.
- This is definitely a more versatile setup.

Option 3 (Failsafe, backup plan): Buy a Lunt 40, single stack, use the Canon R7 if I like the results (if not buy a planetary camera), shoot the eclipse, then sell the solar scope/camera when it's over.

-I think solar imaging is pretty neat, but once I have several full disc images of the sun, what else is there to shoot? I think close up images of prominences or ISS transits would be very cool, but I do not see myself going outside all the time, just to shoot full disc images of the sun. Maybe viewing it would be pretty neat though. Might change my mind once I start imaging it though, who knows.

I know this is a lot of info to process, and I was kind of all over the place. If you made it to the end, God bless you. Hopefully ya'll can provide some insight and point me in the best direction...

Thanks,
Matt

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Matt Dees

Topic starter

Oct 29, 2023 · Edited: Oct 29, 2023

Hmmm. Looks like the daystar quark has a built in 4.2x Barlow lens. That means I would need a super wide telescope to get full disc images with the quark. This rules out option #2.

I guess I'm choosing between a Lunt 40 or 50 and a monochrome camera…

Christian Großmann

Oct 29, 2023

Hi Matt,

I can't really answer your questions, because I never pointed a telescope to the sun. But I want to write some lines to think about.

A setup to take images of the sun may not be the best solution to image deep sky objects. The sun telescopes usually work a bit different than usual telescopes. The light you get with them is optimized for the wavelengths of the elements that emit light from the there. The light is different than the light coming from far away objects.

Monochrome cameras work well with Ha, because the light floating through narrowband filters is usually very weak and the monochrome sensors are much more sensitive than color sensors. But keep in mind, that you need to shoot with different filters to get color images. Taking images during an eclipse will not allow you to do this, because you do not have the time to take different images of the same state. So you'll end up with B&W images only.

A scope like the lunt only has 350mm focl length. So imaging with a DSLR is a bit tricky, because the sun may be quite small in the frame. The sensor usually has large pixels (especially the R5) compared to an astro camera like the ZWO 178 or 174. Combined with the wide field of view, there will not be much detail in the sun at all. So this may not be what you expect. The astro cameras may be the better choice. The downsides of these small sensors may be negligible, because the sun is a really bright object. For deep sky, that's a whole different story, though.

Taking deep space images is a whole different story than taking images of the sun. You need a good mount which allows you to shoot longer sub frames. The mount is the key to everything. Your camera should have a sonsor and pixel sizes that fits your telescope (some keywords: seeing, oversampling, undersampling, etc.). The 178 or 174 (?) sensors may be very small for those kind of images. The cameras should be cooled, to keep the results consistent. But it's possible to use these cameras for guiding.

No matter what you decide, it is really tricky to choose one of the options and later use the equipment for a different purpose. But I completely understand your dilemma and at some point, I had the same thoughts. Then I thought about it and it's the same as with planetary imaging. It would be nice to try, but what's next? There are people out there that love to shoot the same targets (planets) over and over again. That's totally fine. But it's nothing that would keep ME motivated all the time. So I decided to stay with my deep sky subjects I really love.

I hope, there is something useful in my words. I hope, you will make your decision and it will work for you. Maybe, there are other users with better ideas than mine.

So good luck and CS

Christian

Helpful

Matt Dees

Topic starter

Oct 29, 2023 · Edited: Oct 29, 2023

Christian Großmann:
Hi Matt,

I can't really answer your questions, because I never pointed a telescope to the sun. But I want to write some lines to think about.

A setup to take images of the sun may not be the best solution to image deep sky objects. The sun telescopes usually work a bit different than usual telescopes. The light you get with them is optimized for the wavelengths of the elements that emit light from the there. The light is different than the light coming from far away objects.

Monochrome cameras work well with Ha, because the light floating through narrowband filters is usually very weak and the monochrome sensors are much more sensitive than color sensors. But keep in mind, that you need to shoot with different filters to get color images. Taking images during an eclipse will not allow you to do this, because you do not have the time to take different images of the same state. So you'll end up with B&W images only.

A scope like the lunt only has 350mm focl length. So imaging with a DSLR is a bit tricky, because the sun may be quite small in the frame. The sensor usually has large pixels (especially the R5) compared to an astro camera like the ZWO 178 or 174. Combined with the wide field of view, there will not be much detail in the sun at all. So this may not be what you expect. The astro cameras may be the better choice. The downsides of these small sensors may be negligible, because the sun is a really bright object. For deep sky, that's a whole different story, though.

Taking deep space images is a whole different story than taking images of the sun. You need a good mount which allows you to shoot longer sub frames. The mount is the key to everything. Your camera should have a sonsor and pixel sizes that fits your telescope (some keywords: seeing, oversampling, undersampling, etc.). The 178 or 174 (?) sensors may be very small for those kind of images. The cameras should be cooled, to keep the results consistent. But it's possible to use these cameras for guiding.

No matter what you decide, it is really tricky to choose one of the options and later use the equipment for a different purpose. But I completely understand your dilemma and at some point, I had the same thoughts. Then I thought about it and it's the same as with planetary imaging. It would be nice to try, but what's next? There are people out there that love to shoot the same targets (planets) over and over again. That's totally fine. But it's nothing that would keep ME motivated all the time. So I decided to stay with my deep sky subjects I really love.

I hope, there is something useful in my words. I hope, you will make your decision and it will work for you. Maybe, there are other users with better ideas than mine.

So good luck and CS

Christian

Thanks Christain. Very insightful. There is likely no one size fits all solution to my dilemma.

I need to do more research into pixel size, under and oversampling, and seeing conditions for shooting deep sky. I do eventually want an actual telescope for shooting deep sky objects and I would rather pick one best at doing that verses a compromise that will also do solar but might not be best suited for deep sky. Yeah the camera needed for the solar scope is more of a planetary camera and would not be ideal for deep sky, I dont think.

One thing I have enjoyed about astrophotography is competing with myself, over time, to produce better images. My first ever "deep sky" image was a 2 second exposure of the orion nebula off a tripod in 2017. I have come along since then with stacked, 60 second, tracked exposures. It has been fun and I look forward to improving further. I just checked your page out. Very nice images by the way.

I am leaning towards Option #1. Then after the eclipse, I will reevaluate if full disc imaging is something I want to pursue further. If not, I will cut my losses and sell the scope. I just need to decide between the 40 and 50mm scope, and whether doublestacking is worth it in my case.

Matt

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Brent Newton

Oct 30, 2023

Matt Dees:
Hmmm. Looks like the daystar quark has a built in 4.2x Barlow lens. That means I would need a super wide telescope to get full disc images with the quark. This rules out option #2.

I guess I'm choosing between a Lunt 40 or 50 and a monochrome camera...

This was basically my logic in going for a small aperture full disc Lunt and basically swearing off anything close-up until I can get a nice system like an SCT+ERF. The market is obsessed with selling abysmally small apertures on solar scopes (Coronado in particular considering they advertise their models by scope aperture instead of etalon aperture, which is 10mm smaller and forward-mounted), which is fine for mobile use, but I want better resolution and aperture to support it. I simply refuse to start barlowing in on a 60-70mm frac because you hit a useful resolution limit almost immediately with average Seeing