Jump to content


Florin Andrei

  • Content Count

  • Joined

  • Last visited

Community Reputation

4 Neutral

About Florin Andrei

  • Rank

Contact Methods

  • Website URL

Profile Information

  • Gender
  • Location

Recent Profile Visitors

299 profile views
  1. @Rusted - you nailed it. Aries ERF + 200mm SCT is the long-term goal. It should also be able to work in the calcium band. Also - replace the ERF with Baader solar film and you have a great machine for white light imaging. There will be hurdles on the way to that goal, I'm sure, mostly related to the ERF availability and price. We'll see. I'm not afraid of DIY and designing/building systems from scratch. I've a degree in Physics, I've built a dobsonian from scratch (including the mirror), I've built a mirror grinding machine, and now I'm working on a second, larger mirror for a bigger dobs
  2. I always appreciate how much I learn from these impromptu discussions. This is great, it's like I'm back in school again. @Rusted and @astro_al could you please point me at some good material regarding the usage of small Coronado-like etalons with larger apertures? What are the limitations? I will do my best to try and build an H-alpha stack around my 200mm SCT, if I can - in the long run. Well, at least I will see how close I can get to that. There are many, many hurdles to clear on that path (the price and scarcity of full aperture ERFs for example). One unknown is seeing - but I l
  3. I thought about that. But the long-term goal, and perhaps a bit unrealistic, is to be on the lookout for a very large (full-aperture) ERF and eventually move the H-alpha stuff to a bigger telescope. May or may not pan out that way. We'll see. First, I need to make it work with the small aperture.
  4. If you look at the image of the system, the eyepiece appears to be very tall. That's because there are several 1.25" extension tubes plugged into it, with the 0.5x reducer threaded like a filter at the end of the tubes. This is calculated to deliver exactly 0.5x magnification, based on the distance/magnification table for this reducer (distance from reducer to field stop). So yeah, it's after the Quark, of course. Without the reducer, the image is larger and more dim, as expected. Still no changes - it looks like a regular white light image, just painted red. No prominences, no granulati
  5. It makes literally no difference no matter how I turn the tuning knob. Even if I power off the Quark, the image is the same.
  6. Ok, I'm probably doing something wrong. All I see is a smooth red ping-pong ball. No details. If there are any sunspots (right now there aren't any, but I've seen some in the past few weeks), I see them quite well. The edge is sharp enough. Basically, everything I see in the 50mm viewfinder which is equipped with a Baader solar film, I also see in the big scope, except it looks red. I've done visual observations and even imaging before, in white light, during eclipses and the transit of Venus. I was able to capture enough detail and even some granulation in the camera. I'm new to H-alpha
  7. Finally I decided to upgrade the focuser on my ED80 refractor to the Moonlite 2.5". It was time to do that anyway. Very impressed with literally everything about that focuser: execution, feature set, visual design. They have threaded adapters for every format out there, including T2. So I was able to thread the 3x telecentric directly into the focuser. No smooth bore joints anywhere - it's all threaded all the way to the camera. So, with everything installed, I grabbed the butt end of the camera and wiggled it left-right-up-down. To my great surprise, there was a bit of play in the stack
  8. Right. I'll do that eventually, that's the plan, but for now I want to see the whole solar disk at once. I'm pretty sure the disk will get clipped by the Quark at 4x extension (F=2400mm, so the solar disk would be 21mm in prime focus). I will also run it at 4x for highest detail imaging with a good camera, to zoom into smaller features. But that's for later. Like small scale granulation? Or just sunspots and plages? I've seen lots of images taken in H-alpha, but I have a hard time reconciling what I see there with what I could see with my own eyes in a small solar scope. I kn
  9. They say the Quark operates best at f/30 and above. My scope is f/7.5 and I use a 3x telecentric. So I need to stop it down a bit to reach f/30. After I get everything working properly I will experiment with aperture, etc.
  10. I am in the process of getting my first solar scope started - based on an ED80 refractor (stopped down to 60mm) and a Quark Combo for chromosphere, plus the required paraphernalia (3x telecentric, ERF, etc). I've done astronomy for several years before, I generally know what to expect from the night sky. But I don't have much experience with the Sun, except during eclipses and planetary transits I've done some casual observations and a few images - all in white light. So... how much detail can you see, realistically, in an H-alpha scope at D=60mm? I know from white light there's a lot of
  11. So I did some googling and all I can find are 180mm Baader DERF filters. Do they make bigger sizes?
  12. Thanks for all the information, this is very helpful. I've found a CN thread where the stop is said to be 21mm, located at the exit: https://www.cloudynights.com/topic/619797-help-calculating-fov-for-visual-eyepieces-with-quark-chromosphere/ More interestingly, there's another CN thread where Jen (the owner of DayStar) says "a 90mm F/6 = 540mm using a 4X powermate, then a Combo Quark will pass a full disk". https://www.cloudynights.com/topic/534692-daystar-quark-combo-the-new-sctrefractor-model-impressions/ That's D=90mm, F=2160mm, f/24. I only need it to work at D=60m
  13. I see. If I plug the eyepiece directly in the Quark Combo, that would definitely work, because it's very close to the filter. If it's further away (there's a diagonal, etc), then it depends. With the camera, I'll have to keep the sensor as close as possible to the filter. Shorten that side of the stack. Do you know where the 21mm aperture is? Is it at the exit from the Quark? Where do I start measuring?
  14. No, for the full disk I plan to use an APS-C sensor, which is 23.6 x 15.6mm, with 4.78 micron pixels. I am aware this is far from ideal sampling, and I don't care. I have other plans for ideal sampling imaging. My concern is how to get the full, unobstructed image of the solar disk in the focal plane with the Quark Combo. This is for both visual observations and imaging, and the quality of imaging will not be ideal, I know. Knowing the diameter of the blocking filter, to determine the size of the largest unobstructed image in the focal plane, seems like I would have to assume a certa
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.