KTachyon

I was looking at the specs for the RASA 8” and I was a little bit confused about what Celestron actually has in their sheet. So, the RASA 8” is a 203mm aperture with a 93mm central obstruction (ignoring camera cables), which they only state it is 46% of the aperture diameter. But does that 46% even matter at all? I mean, if we calculate the area of aperture and subtract the area of the obstruction it will be about 21% (a far better number for marketing purposes). Doing the math, this means that the aperture without the obstruction would be equivalent to a 180mm non-obstructed aperture scope and, therefore, a F/2.2, not a F/2 scope. Isn’t this correct?

Hey guys! I was thinking it could be great if I could add a reducer/barlow to the RedCat 51 for astrophotography. Is this a good idea? I mean, the ASI sensor seems to cut away quite a bit from the lens view, I think, so I guess that, if I could get a reducer, I could pull more light to the sensor and get a wider view for those really big nebulas, right? As for the barlows, I guess I would need more exposure and guiding precision, but could get more magnification out of smaller objects. Apart from that, I'm unsure about what elements would fit on this setup. I found some for microscopes with a M48 connector, but don't connect to both ends and I'm not sure if it's the same thing. Would appreciate some ideas Thanks in advance!

Ok, so... I guess WO actually sells what I need

Thanks, GlenM. I found some clamps that match those, but might be a though to keep it in place. Maybe i should be looking for an alternative ring for the RedCat 51 that can support a Dovetail on top.

Hey guys! I'm quite new to this. I have a RedCat 51 and I have been able to pull a couple of good sessions using it with a Canon M50 and I'm about to start running with a ZWO ASI. The thing is, I find it quite hard to point the thing to the right objects when aligning the mount without a finder scope. I do have a very low quality red dot finder from an Orion refractor and a ZWO mini guide scope with an ASI 120MM mini mono, both with a dovetail. I was wondering it there was anything I could buy to get those on the RedCat's 1/4-20 holes. I'm not even sure what 1/4-20 means, and I guess that's my main problem... I'm not sure what I should be looking for. If anyone had ideas about this, I would be grateful if you could share PS: I also saw that I could, maybe, get something to do off-axis guiding, but I would prefer the guiding to not have an impact on the main camera (which I believe it has to have, since it has to pull some light off the main in order to support guiding, right?).