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KWIQ GUIDER ???

beamish

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Whippy

Whippy

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Not that I know anything about it but to me, it looks like a 50mm finder scope with a QHY5 on the back of it. I wonder if you can buy it without the camera because I've already got the cam... I'm guessing that would go where your finder is and then you wouldn't need a second scope + bars, rings etc to guide with. Looks interesting :).

Tony..

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beamish

beamish

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Whippy you can buy without the cam for $130.00 Canadian. But is effectively just a 9x50 finder with the QH5Y added instead of the diagonal.I've found a thread on "telescope junkies" where someone has made their own (pic to follow) I'm quite intrigued- might end up buying John's back :)

Karlo

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beamish

beamish

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Ok this is the chap's set-up;

Orion EON 80mm w/WO 0.8 FR/FF

Celestron ASTCG-5GT

Orion Autoguider/50mm Finder

LPI

ATIK-16IC

and here's a pic

10708_normal.jpeg

(click to enlarge)

It would certainly save a lot of weight, esp if like me you're on an HEQ5

He removed the diagonal from the body then added a 1 1/4" t-threaded adapter.

Karlo

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ngc2403

ngc2403

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I have seen this sort of thing before at keilder their was a guy there with the Sbig STV guider and a small lens for guiding. he needed it to guide a pentax and film camera but it was on the AP GTO1200. it looked soooo strange.

the problems with it are that the camera don't have the resolving power of that of a proper guide scope. It can't see as many stars smaller aperture and you need to make it rigid. how ever i thing that it is a great idea and i planned to made an adpeter so i can guide my 5'' refractor through the finder

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ngc2403

ngc2403

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just thinking more about the small size and lack of stars.

if you need to use longer exposures to get a good guide star then it has longer times between corrections and with the lower resolution this could mean that their claim of guiding a SCT would be wrong.

Taking the numbers i hear banded about for guiding i would say it can guide ~0.4 which is 1/10th of the pixel resolution of the guider.

more than have a pixel of motion is trailling to me so i am limited to more than 0.8 to be on the safe side.

with my camera (350D) that means the longest focal length i can guide is 1500mm so a 6'' SCT

In truth the real focal length is dependent on the mount PE. I would not guide anything with a focal length more than 2.5 times the focal length of my guiding setup assuming they have similar sized pixels.

the finder is about ? 250mm ? i think so that is 6 times smaller that the 1500mm theoretical imaging focal length

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Whippy

Whippy

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50mm is a pretty small aperture to try and get a quide star - I find it tough enough with a ST80.

TBH, I would think that the biggest issue isn't aperture, rather the sensitivity of the guidecam's chip. I use my ZS66/QHY5 combo for guiding and have no problems finding stars even without guide rings (so far). Having borrowed a webcam from someone, I can see that they're nowhere near as sensitive as the QHY for example. Meade DSI's and SX Lodestars are more sensitive still I believe.

Tony..

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ngc2403

ngc2403

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50mm is a pretty small aperture to try and get a quide star - I find it tough enough with a ST80.

hey,

what kind of camera are you using? i found out the other night that my st80 and the Orion Starshoot AG are very good together :hello2: .

50mm is a pretty small aperture to try and get a quide star - I find it tough enough with a ST80.

TBH, I would think that the biggest issue isn't aperture, rather the sensitivity of the guidecam's chip. I use my ZS66/QHY5 combo for guiding and have no problems finding stars even without guide rings (so far). Having borrowed a webcam from someone, I can see that they're nowhere near as sensitive as the QHY for example. Meade DSI's and SX Lodestars are more sensitive still I believe.

Tony..

am not sure if the aperture vs chip sencitivity is the main problem. if you have a good sky and seeing is good then the stars will be focussed into just one pixel and so the FWHM will be less than 1! thus the guide soft ware will be struggling to find a centre for the star.

small amounts of error could be invisible to it and it maybe inclinded to over correct for any errors it can see because it will know they are large. i hope this makes sence :scratch: .

in short the guiding being done by the finder is a good compact solution but the short focal length and so low resolution mean that the guider has to be set up just right in terms of aggressiveness to ensure that the guiding on the images is spot on.

Is the QHY5 regarded as a decent Imaging camera in it's own right, and certainly very adept as a guiding unit.?

Ron. :D

it does look to have the good chip sensitivity and clean sensor that makes for good images?

ally

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