New Skywatcher HAC125 F2 astrograph

[Elp]

Hmmm, seems like the Skywatcher HAC125 astrograph is now available to import. Not a bad price either.

Some specs:

125mm primary,

250mm focal length,

F2,

3.7 Kg,

Approx price 500-600 plus taxes.

 

[Elp]

The rub? Apparently only can use 1.25 inch cameras with it.

[TiffsAndAstro]

11 hours ago, Elp said:

The rub? Apparently only can use 1.25 inch cameras with it.

is that limit due to the image circle it produces? what counts as a 1.25" camera? my 533 is a "one inch sensor" (lol) so it would be ok?

im reading 533 is too big a camera for it, but im not sure if the reason is sensor size or camera body obscuring even more of the mirror.

auto focus not possible too?

otherwise this seems a very appealing scope. wonder if there might be a hac150 or even hac200?

[Elp]

It's only 125mm aperture so even a planetary camera will block a lot of area, but I don't think that's the issue, it's the front of camera to sensor distance. The helical focuser on the front doesn't have much travel. The other issue is smaller sensors can be prone to more noisy amp glow as the area on chip is small so you'll see the glow more prominently. I've just played around with Telescopius, I think if the 174mm mini can be used for 60-120s exposures it'd pair well with the scope.

It would certainly make for a nice experiment.

This page has more details about its use (use auto translate in your browser, borrowed from a CN forum https://www.cloudynights.com/topic/919397-sky-watcher-hac125-new-mini-rasa/

 

https://apranat.exblog.jp/35895497/

 

 

[Elp]

Some more detail from an actual SW website:

https://www.skywatcher.jp/news/hac125.html

 

[vlaiv]

One word:

QHY5III585C

[vlaiv]

Actually, ASI format of camera won't add much additional central obstruction.

Specs of the telescope call for 53mm diameter max - but standard ASI body for planetary cameras is 62mm as far as I can tell, so it's only about 5mm more on each side.

[Elp]

Likely I could use my 183 then. Any camera with less than 9.7mm front to sensor distance will do. The other issue would be the usb would stick out the side and you'd see it in star diffraction, with my HS I mitigate this a bit by using a 90 degree usb cable.

Some brands have their usb ports out back on their planetary cameras like the Qhy linked above.

Edited 20 hours ago by Elp

[Louis D]

Does anyone make a wirelessly operated, battery powered camera for these sorts of astrographs?  That would eliminate cable diffraction spikes.  Seems like an obvious product to bring to market.

[vlaiv]

2 hours ago, Louis D said:

Does anyone make a wirelessly operated, battery powered camera for these sorts of astrographs?  That would eliminate cable diffraction spikes.  Seems like an obvious product to bring to market.

Only models that I can think of fall into category of "action camera", but then again - such devices can be adopted for this use as well I suppose.

I guess the main problem is that action cameras are geared towards video recording and employ heavy compression. Don't know if any model is capable of recording raw stills.

 

[Elp]

9 hours ago, vlaiv said:

Don't know if any model is capable of recording raw stills.

GoPro does image in RAW, but my experience with them they get extremely hot, maybe not so when just taking images. Whether you can 1.25 inch adapt it is another matter.

My experience with diffraction patterns on my Hyperstar is to use a full circle shape, edges of which touch the camera side and edge of the scopes OD, a full circle is better than a semi circle, which is better than straight across.

[vlaiv]

41 minutes ago, Elp said:

GoPro does image in RAW, but my experience with them they get extremely hot, maybe not so when just taking images. Whether you can 1.25 inch adapt it is another matter.

I believe there is one GoPro model - GoPro 5 session, that has the right format that can easily be adopted with 3d printed adapter.

There are other cameras that have such or similar slim body that will fit in obstruction.

RunCam has at least few models, for example RunCam 6:

(something like 20x40mm profile)

Or RunCam 5:

~40mm cube.

Not sure how easy is to remove the lens, but I suspect it is C/CS or maybe M12 type lens and thus can be just unscrewed. Again, not sure about raw photo functionality.