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11-04-2017, 09:24 AM
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Registered User
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Join Date: Dec 2015
Posts: 20
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Astrovideography help?
Hello folks,
I bought a 12" collapsible skywatcher dob a few months ago and due to its bulk, have decided to build a somewhat sort of, observatory. I intend, however, on controlling it remotely as it will be on top of my roof. I understand that astrophotography is near on impossible without an equatorial mount, but I am not interested in creating fascinating detailed images, I simply want to enhance what is seen through the scope, onto another display (obviously in as good detail as possible but I am aware of the limitations). During my research endeavours, I came across a couple of companies specialising in this area, however, they all appear quite outdated for some reason. I would like to cap my budget at 500 for the camera, as I have the other equipment. Could one of you kind samaritans please help me in choosing such a camera? Also, what is the best way to motorise my dob, just the GoTo upgrade? Or is there some fancy equatorial GoTo upgrade someone is aware of? All and any help is appreciated! )
Cheers, Harry
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11-04-2017, 01:31 PM
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Not even a speck of dust
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Join Date: Jun 2012
Location: Canberra
Posts: 1,474
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I'm guessing you need a low light camera rather than an imagine camera. Most "night vision" cameras I've used have built in infrared LEDs to illuminate like a torch so not suitable for a telescope. So i would start by investigating the lux values of cameras, a dslr or similar that can be tethered might be suitable but it may be a guiding camera sensitive enough. either way I dont know if colour is feasible, you want low noise, possibly cooled. Wireless not likely so make sure you dont end up winding cables around a "rotating" telescope. Not sure $500 is a realistic budget for a camera.
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11-04-2017, 04:37 PM
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Local Korean Millennial
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Join Date: Dec 2009
Location: Charleville
Posts: 2,063
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Just wondering, wont a telescope on the roof be subject to massive vibrations whenever theres movement in the house? also this thread helped heaps for me to get started. http://www.iceinspace.com.au/forum/s...d.php?t=139900
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11-04-2017, 08:56 PM
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Registered User
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Join Date: Jun 2012
Location: Young Hilltops LGA, Australia
Posts: 1,272
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Some Occultation observers use the super circuits PC164C - an analogue mono video camera with oodles of low light sensitivity. The camera has an output you can view on a video monitor but more difficult to capture digitally.
"Astrojunk " uses a Gstar ex camera. He's a very nice guy you could send him a pm.
You could also look at the zwo cameras.
Joe
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12-04-2017, 05:46 AM
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Registered User
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Join Date: May 2015
Location: Lismore NSW Australia
Posts: 242
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Take a look at the Revolution Imager.
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12-04-2017, 03:53 PM
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Registered User
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Join Date: Dec 2015
Posts: 20
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Thanks guys for all your replies and I have taken all of your advice. I am actually quite interested by the revolution imager r2. The only thing I am confused about is why it doesn't have an HDMI out? Is that to save space or am I missing something entirely? Also, there is obviously some exposure time needed in order to create any live footage etc. so I was just wondering, is a goto dob sufficient in keeping an object in the centre of the frame across the sky for astrovideo use? Is anyone aware of somebody who has done astrovideo with a goto dob? Sorry about the questions guys but I really don't want to make a wrong purchase! hahaha
Cheers all, Harry
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13-04-2017, 08:09 AM
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Registered User
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Join Date: May 2015
Location: Lismore NSW Australia
Posts: 242
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You are right about the lack of HMI output on the RI r2. The small screen I have placed on a flexible stalk, from an old desk lamp which required fittings welded on. I mainly use it for outreach purposes, connected to a small projector that has an AV input and a portable screen. The r2 comes with an AV to USB device, at least it did when I bought mine, for video capture. I have used one minute exposures to capture video and stack in Registax. The results are not perfect, given that I have an alt-az mount, and field rotation can be a problem. Also there is some blurring at the far edges of the image, but perhaps a field flattener could correct that.
This was taken with RI r2, 10" GOTO dobsonian, 2" 2 x Barlow. 30s exposure. http://imgur.com/a/EmLHd
There is a multitude of exposure settings available via the camera menu, the wired remote makes it pretty easy to scroll through all the settings, however, learning which settings are best for the object in view, and remembering them, was frustrating at first, I took notes and keep them with the kit. I haven't looked at the website in a while so maybe they have updated the info on the r2.
GOTO tracking accuracy: I have placed leveling feet on my dob base, I use a spirit level, do my alignment and then check its accuracy with SkySafari 5 with a Nexus-S Wifi hook up. Using my phone is quicker than the GOTO handset for locating objects.
Here's some live views from Youtube. https://www.youtube.com/watch?v=GSUBnEk4kBE
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13-04-2017, 11:54 AM
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Registered User
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Join Date: Aug 2015
Location: Sydney
Posts: 1,754
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So astrovideo – you want to see some stuff live on a monitor or computer. For astrovideo you need a goto mount, otherwise very difficult (but some do it on a dob with a lot of focal reduction). Most people use an alt-az mount as easier to use, and fine as you only need to take 5-20sec shots and stack them over a few minutes.
The camera depends if you want to just plug into a monitor or go via a computer.
Via monitor you can go with the likes of the revolution imager, or some sort of mallincam. But these won’t be cheap as you’ll have to import from USA. There aren't any decent cameras out there with HMDI for astrovideo. The drawback is resolution with these. If you want to plug that through a computer the resolution of the analog-USB devices is terrible.
Via computer. The IMX224 colour based cameras are all the rage. Bintel for $420 is the ZWO ASI224MC (make sure you get one with a version 1.3 board, not the older 1.2, as the new one as amp glow reduction circuitry). On aliexpress Rising Tech have a clone which is even cheaper. You'll need a computer - rising tech has their own software, or use the free(ish)ware sharpcap. Both have excellent stacking software and you'll get some nice live images within a minute or two depending on the object.
Either way, you'll need some focal reduction (what Fratio is your dob?) to get a faster images and larger field of view. You can start with a cheapie x0.5 from Bintel or anywhere. This is OK with the small 1/3" sensors – astrovideo doesn’t care about coma etc on the edges.
Definitely have a look here
http://astrovideoforum.proboards.com/ and
http://www.cloudynights.com/forum/73...ted-astronomy/
These are dedicated to astrovideo. Its live imaging, nO astrophotography post-processing on these sites.
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13-04-2017, 12:02 PM
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Registered User
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Join Date: Dec 2015
Posts: 20
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Quote:
Originally Posted by ChrisV
So astrovideo – you want to see some stuff live on a monitor or computer. For astrovideo you need a goto mount, otherwise very difficult (but some do it on a dob with a lot of focal reduction). Most people use an alt-az mount as easier to use, and fine as you only need to take 5-20sec shots and stack them over a few minutes.
The camera depends if you want to just plug into a monitor or go via a computer.
Via monitor you can go with the likes of the revolution imager, or some sort of mallincam. But these won’t be cheap as you’ll have to import from USA. There aren't any decent cameras out there with HMDI for astrovideo. The drawback is resolution with these. If you want to plug that through a computer the resolution of the analog-USB devices is terrible.
Via computer. The IMX224 colour based cameras are all the rage. Bintel for $420 is the ZWO ASI224MC (make sure you get one with a version 1.3 board, not the older 1.2, as the new one as amp glow reduction circuitry). On aliexpress Rising Tech have a clone which is even cheaper. You'll need a computer - rising tech has their own software, or use the free(ish)ware sharpcap. Both have excellent stacking software and you'll get some nice live images within a minute or two depending on the object.
Either way, you'll need some focal reduction (what Fratio is your dob?) to get a faster images and larger field of view. You can start with a cheapie x0.5 from Bintel or anywhere. This is OK with the small 1/3" sensors – astrovideo doesn’t care about coma etc on the edges.
Definitely have a look here
http://astrovideoforum.proboards.com/ and
http://www.cloudynights.com/forum/73...ted-astronomy/
These are dedicated to astrovideo. Its live imaging, nO astrophotography post-processing on these sites.
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My dob is 1500 by 300 so f5, would I still need a reducer? Also, what about this zwo from bintel https://www.bintel.com.au/product/zw...sb3-0-colour/? because I do want it computer controlled. Any cheaper alternatives to the IMX224?
Cheers!
Last edited by WaTcHuLoOkNaTm9; 13-04-2017 at 12:17 PM.
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13-04-2017, 12:20 PM
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Registered User
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Join Date: Aug 2015
Location: Sydney
Posts: 1,754
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Not the 120, the 224MC is a much better camera for this. If you don't want to spend the extra then go the rising tech. You might ask on astrovideoforum where people are buying them - there's a few Aussies there who will know. I think its on aliexpress.
The computer control is really easy with sharpcap etc. Just a single USB3 cable and you'll get some nice instant images.
F5 is great, but 1500mm is a very long focal length. Think of the 1/3" cameras as being similar to 6mm eyepieces - you'll have about 11' x 8.5' FOV ! So you will have problem staying on objects and will be restricted to really small objects. Go the focal reduction.
Most people use a small refractor (semi-apo if possible), a fast 6-8" newt, or 6-8" SCT (with x0.33-0.6 focal reduction).
I use the first two, but have used an SCT in the past - I like the large FOV objects, so go for FOVs from 30' to 2.5degrees.
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13-04-2017, 12:27 PM
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Registered User
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Join Date: Dec 2015
Posts: 20
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That almost seems to good to be true at such a low price! I will look into it thanks a lot for the suggestion. Would a 0.5x focal reduction be adequate? Thanks
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13-04-2017, 02:33 PM
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Registered User
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Join Date: Aug 2015
Location: Sydney
Posts: 1,754
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Thanks Chris. Yes I linked the usb2. Gee that makes their usb3 about as much as the zwo through bintel ?
Unless doing planetary you don't need usb3. All my live DSOs on the zwo were done through a usb2-only computer.
You can try a cheap 0.5 reducer. They are variable in quality but see how you go. I've never used a focal reducer on a newtonian - just on SCTs and refractors - and then I used sct reducers on both, except I used to have the old analog Rev imager and it came with an antares 0.5 reducer.
Theres a few people on cloudy nights doubling up 0.63 and 0.5 reducers to get their SCTs down to F3.
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13-04-2017, 02:52 PM
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Registered User
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Join Date: Dec 2015
Posts: 20
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I might not worry about reducers and the like until I can experiment a bit and be confident with what I need. I, funnily enough, am really considering this camera https://www.myastroshop.com.au/produ...asp?id=MAS-025. Plus it is all Aussie owned and seems like a darn good little machine.
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13-04-2017, 03:47 PM
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Registered User
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Join Date: Aug 2015
Location: Sydney
Posts: 1,754
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Funny that, I just remembered that one and was coming back to mention it. You beat me to it ! I think it has been used by a few on astrovideoforum
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