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Post by Deleted on Nov 19, 2013 23:17:08 GMT
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Post by davy on Nov 20, 2013 22:26:12 GMT
Quite fancy a computar lens, auto iris auto focus ect
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Post by Deleted on Nov 20, 2013 23:25:41 GMT
Hi, all sorts can be used. The main issue for astronomy is the FOV more than anything else as they are all designed for security.
Auto and DC lenses are designed for adjusting light between day and night so when the sun comes out the camera auto adjusts the iris to cope with the light, to me not much use as the cameras used in astro are only on at night so I use manual type.
Normally the lowest is 2.8mm and give a wide FOV of around 80 Deg which covers a lot of sky.
Over all I think a 2.8 to 8mm gives good all round usage.
It depends on what your using it for at the end of the day.
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Post by Deleted on Feb 13, 2014 0:24:04 GMT
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Post by Deleted on Feb 13, 2014 1:03:00 GMT
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Post by Deleted on Feb 13, 2014 1:25:32 GMT
These look good chaps I look forward to seeing how these perform.
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Post by Deleted on Feb 13, 2014 1:27:14 GMT
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Post by Deleted on Feb 13, 2014 1:37:56 GMT
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Post by Deleted on May 25, 2014 13:44:57 GMT
Ok guys, you have been looking into this for a while. What lens did you settle on? I have setup my SDC 4000 with my 18-55 dslr lens and although it works fine, the FOV is very restricted. I can't quantify it, but it would just about fit the big dipper into it. Not quite wide enough for a decent view of the sky for meteors etc. Open to suggestions. Edit. so I put a baader filter on it and pointed at the sun. the sun is the size of a small pea, so it may not be as bad as I thought. Still not quite wide enough though.
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Post by johnno on May 25, 2014 14:11:33 GMT
I use a couple of different one's, 80-200mm M42 fit slr lens with adapter, you can pick these old lens up dirt cheap on ebay and experiment with them, and a 2.8-12mm auto iris. Alan try a 120 or 150 c mount degree lens. I used my 2.8-12m lens for meteors www.flickr.com/photos/tfc475/with/9501408429/ gives you a rough idea of FOV
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Post by Deleted on May 25, 2014 14:38:58 GMT
Ta johnno, I'll try it out tonight and see what fits in the frame. I don't want a fisheye or super widefield or I will be getting houses in the fov. I think the 120 might be suitable but until I try the 10mm dslr lens I won't really know. Maybe when I can take an image with it, someone can calculate the FOV for me so I can decide what I want.
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Post by Deleted on May 25, 2014 14:52:52 GMT
I can second the 2.8 - 8mm CCTV lens at 2.8 it almost becomes fisheye but you can narrow the FOV easy to what suits up to 8mm which cuts out houses etc. Works great for meteors. I think the FOV at 2.8 is around 80 deg or so.
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Post by Dragon Man on May 25, 2014 15:18:14 GMT
John, that is a nice wide FOV you have on those meteors without going to an All-Sky lens. Well done.
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Post by johnno on May 25, 2014 15:49:56 GMT
this image is using the 200mm lens on the video cam.
this image is using a 200mm lens on a dslr but in effect its 400mm on a panny micro 4/3 sensor. has you can see there's a massive difference between the video cam and dslr when using the same lens
this image is the 2.8m -12mm cctv lens on the video cam. @ about 7mm
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Post by johnno on May 25, 2014 15:52:06 GMT
Thanks Ken, I think the lens is just about right for meteors
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Post by johnno on May 26, 2014 14:49:10 GMT
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Post by Deleted on Jun 18, 2014 12:54:51 GMT
Hello Group, I need advice as always
I currently have a 2/3" 2.0 mm fish eye lens and it works great with the Xtreme but no other camera. This I am assuming is due to the different chip size in the Xtreme but what do I need to look for to use on the other cams, Sammy, CR6 etc.?
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Post by davy on Jun 18, 2014 17:29:19 GMT
1/3 rd lens
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Post by Deleted on Jun 18, 2014 18:52:23 GMT
1/3 rd lens Cheers Davy
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