Very useful information all the way through the video! Thanks for making this video, it really helped me understand way more about focal ratios than I knew before. I’m a new 8SE user thinking about photography.
In photographic a focal reducer increases the amount of light delivered to the camera sensor per unit time, allowing for shorter exposures. For visual use, you get a wider apparent field of view, usually at the cost of enhanced edge aberrations.
It's a very nice explination how the focal reducer works, but I read and think that it is logic, that if the reducer concentrates mor light at one pixel you have mor light per pixel, so you have not the same amount of light like f/10. You have more light.
I am searching past 1 week I. UA-cam. I wasted my time.
Your is very use full and more information I got. I clear my mind and learn very much about focal length and wide filed view. Practically you explained very well. You are the Good and Greate. 👌
very well explained; one of the best videos on this subject
You can use this telescope to capture beautiful long exposures pictures with the hyperstar and the equatorial wedge.
Great setup for under $2500
thanks ray
I bought a Celestron 6se optical tube and it arrived today. I hope to use it for lunar and planetary work. I have a Bresser 102/460 ed refractor which is f/4.5 or f/3.6 with my x0.8 field reducer/flattener, which I use for big things like Messier 31. It works great, but when I look at Saturn, it looks like a star. I use a ZWO asi294 camera.
I am considering getting a HyperStar 6 v4 (Only $400) which is only usable for photography, but I am not sure, yet.
This is where having a background in photography really comes in handy. Don't quote me on this, as I'm pulling this from memory, and I may not be 100% correct. But the theory is correct and it kind of helps explain a fast OTA vs a slower OTA. I purchased an 8" Edge HD which for all real purposes is the 8SE but with more expensive optics. But I got it for the same 3 in 1 reasoning. I got the .7 focal reducer for the Edge HD and the Hyperstar for the 8" Edge HD as well. If I shoot the same target at f10 (2032mm) my exposure would be much longer. If it was a deep sky target I would probably shoot either a 6-7 min long exposure or more likely just a boat load more subframes at shorter exposure times. Where if I'm using my .7 reducer I'm around F7 and 4 mins is usually pretty good. And of course I get the much wider field of view. With the Hyperstar on the front, I'm shooting at F2 and 30 second subs is all you need. I shoot multiple targets in one night getting 300-400 subframes on each target. It's basically turns the Edge HD into a RASA. It feels like your cheating it's that easy. But I was always told that changing one f stop, say F4 to F5.6 you lose half your light. From F5.6 to F8 same thing. F8 to F11 same thing. That's why using a Barlow doesn't hurt that much because your probably shooting Jupiter or Saturn. Even Mars is bright enough that F25 is still manageable. Where you would never should a deep sky object at F25. The one thing in photography that is never mentioned in astro-photography is the depth of field. At high F ratio's you get a better depth of field. Meaning the distance in front and behind your target where the image is in focus is much greater. At the distances we shoot at, it's probably a moot point. But I bet the rule still applies even at light years of distance. Anyway.... Just a thought.
Cheaper option would be to use 0.5x reducer or get a f/5 61mm or f/5 102 refractor and mount on C8 and then use a camera. You can get Apo quality lens system for the same price. I sometimes wonder why these focal reducers are so expensive, they are not even flourite grade glass.
Sometimes I think the same Anand! It does gives you joy when you are making these slow scopes turning into fast scopes. Thanks Anand!
can you look through Hyperstar and get F4 , like a Newt 8" on Celestron Advanced VX 6" SCT
Hi Thanks for watching one of my oldies! LOL. No you cannot watch through Hyperstar. It is designed to remove secondary mirror and hijack the signal and sends it directly to camera. It is not designed to watch.
I have 3 questions.
- Do you still need the reducer if you buy hyperstar?
- Do you still need eq Mount if you buy hyperstar?
- Do you suggest wedge or professional eq Mount if we still need eq Mount for deep sky astrophotography?
Thank you 🙏🏻
1) if you use hyperstar your camera is not mounted at the back . It replaces the secondary mirroe --> no focal reducer
2) an eq ,ount is always better for astrophotograhy. if corrctly polar alligned it only needs to move one axis . the az mounts always need to move two axxis --> not that accurate
3) I would alway suggest an eq mount
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Right? 😂
Two tousand...two tousand two hundred mm....F/10..dis is your focal length. What? I mean, what? Just because you can make a video doesn't mean you should!
I also have a 8SE and I'm using it with an ZWO ASI 224MC Astrocam. I can see a bigger field of view because the amount of light on the 203mm Mainmirror remains the same although you have the same amount of light compressed and brighter in the focal point.
Please make your entire thesis at the very start, or in the Description. 30 mins of rambling video does not . In a sentence, what is the point you are making here?
AntPDC that is a great feedback you have a good point there. in one sentence - three different field of views and one telescope
AntPDC please provide me good feedback like this. It is one of my first videos and the newer ones I kept it 10 minutes or so
I did not wish to be overly critical. I know FAR less than you about these technical matters: it's simply a question of communication - especially to an audience with an increasingly narrower attention span! I am grateful for your temperate response Ray. Best wishes.
AntPDC I completely understand and agree. You are spending your 30 minutes. I need to better justify why. Love your feedback.
Thank you Dave, I have been researching the celestron 8 and you are helping me understand this scope. Great video.
Thanks John..King!!