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Forum: Pentax Q
02-24-2021, 10:48 PM
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That's great, really promising!
You should post the picture of your white Q on white telescope!
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Forum: Pentax Q
12-03-2020, 04:49 PM
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Hi Transit, congrats for your new scope! 6" F8 (that's 1200mm focal length) is great, make sure to share your results (photos as well as eq mount setup, that would be one heck of a mount)!
Since you think the tube is too short, I assume that you can achieve a good focus visually when you slightly pull the eyepiece out of the focuser tube. If that's the case, most likely you're good.
Once you get Q to C and C to 1.25" adapter, I recommend that you first try to see if prime focus (no eyepiece, no barlow) works. It might just work, but if the focuser tube still seems to be too short, buy C-mount extension tubes and insert one (or more) between the Q to C adapter and C to 1.25" adapter.
They usually sell these tubes as a set of 3 or 4 pieces, e.g. amazon.com : Evertech 5pcs 5mm Camera C-Mount Lens Adapter Ring Extension Tube C to CS Mount Lens Black Aliminum Adapter for Most Types of CCTV Security Cameras : Camera & Photo?tag=pentaxforums-20&
For K mount cameras, usually prime focus on Dobs won't work, barlow gives you some wiggle room.
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Forum: Pentax Q
08-18-2020, 10:23 PM
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I'm not sure how I managed to miss your shot from Hong Kong, it's a great land/star scape!
Concerning your scope, if the telescope tube length is significantly shorter than the nominal focal length of 1000mm, I'd say it's a Bird-Jones type telescope, i.e. a scope with a spherical mirror of shorter focal length, probably 500mm, and a built-in barlow (teleconverter) to achieve the nominal focal length.
But I don't know whether or not you should remove it, I think you should try it on your own to conclusively say anything.
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Forum: Pentax Q
03-09-2020, 10:44 AM
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Sharp eyes!
Yes it's sticky-backed flocking I bought it from scopestuff.
ScopeStuff
I don't know if that's better than something available on Amazon, but this thing works. It's much better than any matte black paint I've tested including but not limited to chalkboard paint.
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Forum: Pentax Q
02-28-2020, 07:28 AM
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2old4toys, there's a couple mm of headroom left.
Piotrek K, good to know that your Newtonian doesn't need anything special! I tried my Q7 with the machined adapter on my friend's 10" Dobsonian, it didn't reach the infinity but I didn't have audacity to ask if I can remove eyepiece adapter as it looks so nice and expensive. ;)
I'm not that worried about dust as the sensor is facing down, not up, when in use. Like Piotrek K, I put my 1.25" eyepiece cap when not in use.
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Forum: Pentax Q
02-27-2020, 01:31 PM
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Hmm, I wasn't thinking it through, machining was necessary after all for my purpose.
If I didn't machine it, the outer part of Q-C adapter would have interfered with the focuser adapter ring, and I'd have only gained ~1mm (basically the thickness of the lip of C-1.25" adapter) instead of ~5mm.
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Forum: Pentax Q
02-27-2020, 12:26 AM
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I already replied to 2old4toys via PM, but anyway. In the past I made this post about removing the eyepiece adapter on the focuser, that's one way to achieve infinity focus on my Newtonian scope (but it might not be enough depending on the scope).
https://www.pentaxforums.com/forums/136-pentax-q/292702-astro-nature-telesco...ml#post3217010
Since that post, I thought that unscrewing focuser adapter ring each time I want to take a picture is annoying, so I modified Q-C adapter to remove about 5mm or so.
In the attached, to the right is the original Q-C adapter, to the left is a modified Q-C adapter with C-1.25" adapter. If I make the second one, I'll just throw away the inner ring of the Q-C adapter, make the C-1.25" adapter sit flush on the surface where the ring used to sit, and epoxy the two together, taking time to make sure that the two parts are concentric. That's basically what I did except that I machined the Q-C adapter, that was unnecessary. Originally I planned to make this a three-part system that are screwed together, but before making the third part I thought that epoxy might work as well, tested it (JB Weld) and was satisfied with the strength.
Anyway, on my scope, with this modified adapter I don't have to remove the eyepiece adapter.
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Forum: Pentax Q
07-23-2018, 02:11 PM
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Hey geo444, I just wanted to tell you that I'm REALLY interested to see your tips! Take your time but keep us posted!
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