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Post by Deleted on Oct 16, 2015 20:21:54 GMT
Okay, not seeing a category for this I'm just going to wing it here. After awhile with my Orion XT8 I have found a few things that are stopping my progression . First I tried to simply find my target using my iPhone and an excellent app but it is a hit and miss knowing if you have the correct target insight. Then I tried purchasing this "neat" little usb cam to "see" objects better in my scope. The cam is okay for the moon and that's about it. So new plan, downloaded Stellarium . WOW an excellent program ! I have a knack for software so it wasn't long I realized I can use this program to POINT TOO anywhere I want. I was wondering if ya'll are doing the same. I could"theoretically" install a camera that I can actually see DSO and use split screen to align the target with Stellarium and then use an equatorial platform to track with. Sound like something I could do? Questions I have is 1. Orion XT8 - Is this going to be the scope I want to do this with? I would think I could see DSO's better with the 8". I have found an excellent Dark Site. 2. Whats the specs on the Sammie that make it the perfect cam? The TLV? the sensor? I'm seeing about a thousand window cams and one or two Mac cams for astrovideo, but sometimes that's the way the cookie crumbles. Whats a pretty decent cam for under 500 or should I just simply go the sammie cam route? I want to see DSO . I don't expect a hubble view but I do expect to distinguish certain objects. 3. I see a huge amount of Newts or DOBs as some people call them on the internet being used for AV. Yet I see a huge amount of smaller 80mm scopes being used. Is this just a preference? I saw Forest Tanaka using a Canon lens and achieving beautiful astrophotography pictures. I'm thinking it's in the cam? 4. One thing more ! Is the view you see in Stellarium (after setup ) anywhere close to actual view you would see in various scopes and lenses and cams? if so WOW, this would be a perfect way to test eye pieces, cams, and scopes.
Funny thing is, all this headache is GREAT ! Gets rids of the cobwebs in the brain !
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Post by davy on Oct 16, 2015 20:48:11 GMT
Hi. The 8" scope ..yes can be used for video... question is what can you view with it.. I would try experiment and come to your conclusion on what you will see.. Fit a 6mm eye piece to your scope and point It at the moon.. this will be what can be seen with a samsung camera fitted to your scope.
If it's the moon / planets great if its deep sky objects you will struggle to get a decent full fov without adding focal reducer..this is where the likes of the ed80 comes into things.. it's a fast scope and gathers photons faster and at a wider fov..the faster the scope you can then keep your intregration lower reducing noise which helps if you wish to stack captured images from your video.
My set up this season.. is an sw ed80 with 0.85 focal reducer/flatner and try some video capture via canon 600d on video mode , i will be buying a guide finder scope from ebay and fitting a qhy5l 2 video camera to give me a large fov this will be run on sharpcap and give me long exposure mod.
what I was using last year may be what you are looking at or a variation, I was using a sw eq3/2 pro I had this linked to my computer using eqmod,i preferred carte's de ceil to stellarium as my scope interface in eqmod...stellarium looks good and realistic but in my honest opinion cdc is better.
Samsung scb2000 with the factory fitted I/r filter removed is a big step up from a webcam or mobile on projection,,,the Samsung has a more sensitive sensor but this is not enough we require intregration ( slow shutter or long exposure mode) the Samsung can be set from x2 to x512 in sense up mode ,,this is what you require to see deep sky objects.
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Post by Deleted on Oct 16, 2015 21:05:45 GMT
My XT 8 has a focus ratio of 5.9, is that too slow?
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Post by davy on Oct 16, 2015 21:13:22 GMT
f 5.9 is ok for speed ,,that is faster than the ed80 ,,and you can speed it up further by using a focal reducer,,what it will come down to is your preffered field of view,,i shelled out £164 on a focal reducer to be able to squeeze out a bit more fov and get a better flat field view from my ed80.
even at this I want an even wider view and do longer exposure,thats why im buying a finder/guider scope...I could have bought an adapter to fit a canon lens to a video camera to get a fast capture with a wide view,,lot of people ddo this as an allsky camera.
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Post by Deleted on Oct 17, 2015 6:48:28 GMT
Interesting , it's the trade offs I need to learn. This is why I love this forum ! So i'll be losing FOV but I'll be gaining speed by using the " bucket " to gather the light and send it down to the camera. As a beginner I think I can live with that. If not I can go after another scope later. So the main thing I need to concentrate on is the Cam. Weight is an issue as well as portablility as we have retired and live full time in an RV. So I plan on seeing lots of different states and stars !
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Post by davy on Oct 17, 2015 8:07:05 GMT
The shorter the tube the better, camera wise the samsung is a great camera and the menu buttons can be accessed remotely using a utc ( up the coaxial) controller..another good camera and smaller is the ln300, this camera is tiny compared to the samsung, it has twice the intregration of the samsung it will go to x1024 in sense up mode, there are details on cloudy nights how to make a remote keypad to control the menu. Mallincam does a version of this..ken will jump in and give you details on this... aliexpress is the usual source for picking up the ln300 ..get the pal version it's better than the American version the usb grabber will convert the analogue signal to digital for computer use.
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Post by Dragon Man on Oct 17, 2015 13:18:49 GMT
So i'll be losing FOV but I'll be gaining speed by using the " bucket " No, by 'increasing' FOV you will be gaining speed. If you lose FOV you lose speed. The old method of 'Aperture, Aperture, Aperture' doesn't really work with Video Astronomy. What works with Video Astronomy is 'short short short' The problem with Aperture is that it usually comes with the added problem of Loooooong focal lengths. Think 'short'. That's why small richfield Refractors are so popular. Not 80mm or 100mm refractors at f/9 or f/10. They come in loooong focal lengths. Try stay 750mm and shorter in focal length. The popular Skywatcher, Orion, Saxon, ED80 comes in 600mm for the f/7.5 models, and William Optics ZenithStar 80 II at 545mm for their f/6.8, and Explore Scientific come in 480mm for the f/6 models, and there are others. Larger Aperture refractors are best kept at 750mm and under which is f/5. Try keep their focal length as short as possible. Astrophotographers like to talk in terms of focal ratio. For Astrophotography an f/5 16" Reflector is great. But it has a focal length of 2,032mm (GASP!).
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Post by davy on Oct 17, 2015 13:27:51 GMT
nice one ken,,thats what i was trying to say ,,lol
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Post by Deleted on Oct 17, 2015 14:59:45 GMT
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Post by Deleted on Oct 17, 2015 15:30:46 GMT
I think I'll just slip in a Mallincam Micro and be done with the camera part right now. I see some beautiful shots on the Mallincam website from this little cam and that's exactly where I want to head with all this.
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Post by davy on Oct 17, 2015 15:45:09 GMT
Same camera with mallincam badge basically.
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Post by Deleted on Oct 17, 2015 15:50:12 GMT
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Post by davy on Oct 17, 2015 16:08:21 GMT
Getting there... I use the ezcap myself and can recommend it..buy genuine one not an ebay Chinese copy.
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Post by Dragon Man on Oct 17, 2015 17:01:13 GMT
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Post by Deleted on Oct 19, 2015 3:08:45 GMT
Well made an very enlightening trip to our local college observatory last night and found out some things I never would have thought. There is a limit as to how much I want to "SEE" with a cam. I looked in several scopes, all visual, all the way up to a Giant C 14 ( for me it was huge!) and there was a breaking point where I saw so many stars that I could not see what I was wanting to focus on. I guess a visual overload for me. Interesting, as this helped me narrow down to what degree I want to be able to see and what cam I really need to be dealing with right now. I'm ordering the one from Ali express next week and the video grabber card. Yes the card Ken suggested. I've went back and rewatched his videos again and he has too many scopes. LOL> I really enjoy his videos.
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Post by davy on Oct 19, 2015 7:13:23 GMT
Great news on your kit your ordering..the camera is more sensitive than the samsung so if you have dark skies you will have fantastic views with it.
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Post by Dragon Man on Oct 19, 2015 10:33:37 GMT
Cooool, thanks Crowman I made the Videos to help people, and so far so good Yeah, the little LN-300 is a better camera than the Samsungs that many of us used (and some still do). I just got mine from OC Telescope in California today (the Revolution Kit). Nine days delivered to my door in a rural town. Not bad! I haven't opened the box yet but when I do I will video the whole unboxing thanks to davy reminding me to do it
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Post by davy on Oct 19, 2015 12:44:29 GMT
Looking forward to you starting a revolution. I saw the thread in cn lol ..enough said lol.
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Post by Rick in NWArk on Oct 19, 2015 16:47:30 GMT
With video astronomy, everything comes into play: - focal length of scope x camera chip parameters determines field of view - f/ ratio & aperture x camera exposure + gain determines sensitivity and how deep (magnitude of objects) - mount alignment / tracking / field curvature can limit exposures - video has been known to cut thru haze and bad seeing and light pollution; filters always help
And yet with all that, people have been able to do video astronomy with almost every setup you can think of.
Naturally, you wont see as many people using dobs fore regular work - with no tracking, it takes extra work to keep the object in the field of view. I've seen a lot of people broadcast with an 8"f/10 scope on AltAz with fantastic results.
* In general, expect video astronomy to triple your aperture compared to visual. That means that you'll get colors and be able to pull faint smudges that your eye cannot see or process.
* There is no perfect setup; there are many good setups that are versatile
Hope this helps!~
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robrj
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home town/country: Escondido, CA
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Post by robrj on Jul 1, 2016 19:53:35 GMT
I'm quite late to this topic but I thought I'd add what I did with my Celestron 12" f/5 dob in case anyone else stumbles across it.
First, I put Manual Setting Circles on it. I did that back when I was just doing visual. It really helped to get the object in the field of view (at least close) in my 24mm 82° eyepiece (about 1.5° field of view). For tracking, I put together a TL Systems equatorial platform. It's intended for visual use but I can get usually get a couple stacks out of it (my M16 was 4 frames at 8 seconds). I may upgrade to a better quality platform or buy a goto dob upgrade kit (I've seen the Aussies sell them and they're willing to ship).
For video astronomy, I found it was still difficult even with the setting circles. The problem was using the visual finder scope on dim objects combined with not being dark adapted because of the computer screen. I would get in the area of a dim object but visually, I couldn't see deep enough to know where I was. In addition, the San Diego light pollution blotted out a lot of the dimmer stars. I have an Orion 50mm Guidescope that I was just starting to use for wide field video astronomy. So I thought, why not get a cheap camera and use it as a video finderscope. Luckily, I happened to win an Ultrastar-C at OPT's SCAE. So now I use the 185MC in the 50mm as a finder in place of my visual finder. Combined with the manual setting circles, brighter objects like M16 or M8 just show up in the wide view. I don't even have to star hop. For width, it gives me about 2.4°x1.5° according to Astrometry.net. I just now thought maybe I should try my 0.5x focal reducer on the finderscope as well. That would give me a wider view closer to a traditional finder.
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