Log in

View Full Version here: : Question for RASA 8 owners


The_bluester
17-01-2020, 10:08 AM
I have very nearly completely written the idea of a RASA 8 off and was going with a high quality frac (Albeit much much slower)

On the other hand I am stalled at waiting for a quote inclusive of shipping for the scope I had settled on and have been for a couple of weeks, the RASA being available retail in Aus starts to look more attractive again.

Can anyone with a RASA 8" confirm what the thread of the optical window or LPR filter is? The dimensions in the RASA spec sheet suggest it might be a standard M48 thread but I have not seen it written down anywhere. Previous experience with my camera on a variety of scopes says that a filter limiting the bandpass into the visible spectrum is essential to control reflections but I am not in a noticably light polluted area and taking chunks out of the spectrum around sodium, mecury vapour lights etc would be less attractive if it could be just a straight cut at the IR and UV ends with everything else passed through.

lollywater
18-01-2020, 04:05 PM
Paul
The Celestron LPI filter is 46mm.
Image 1
The image on the right is the Celestron LPI filter and the one on the left is a 2 inch filter.

Image 2
I am aware of only 2 options for 2 inch filters on the RASA 8. The first is the Artesky 2 filter adapter and the second is from Starizona.
The Artesky replaces the M42 camera adapter . The Starizona attaches to the Rasa 8 camera adapter and only fits ZWO 294,183 and 1600 cameras.

When I first bought the Rasa, the Celestron LPI filter was the only available, then came the Starizona and then the Artesky. That is why I have each.
A very expensive pathway.


cheers
Paul

The_bluester
18-01-2020, 09:48 PM
You would reckon they would just use a common thread.


I am trying to get a really nice refractor lined up, but if I can't get it to fall in to place I am still tempted by the RASA 8, possibly even with a full frame OSC camera like the new ASI6200, the stars might be wonky and vignetting might be well in play by the corners but it would allow imaging without ever having to rotate the camera, just crop to suit the largest frame before abberations became obvious, in any orientation you want.

But my previous experience says that a UV-IR filter is quite valuable for keeping reflections at bay with at least some of the OSC cams but I don't see the point of notching out the common LP wavelengths as the Celestron filter would for my application as I am in a decently dark area. Just a nice lum filter would be the ticket.

lollywater
19-01-2020, 12:44 PM
Paul
I am still very happy with my Rasa 8,but I just need a fast scope that will give me a lot of detail quickly
cheers
Paul