andrew s

Good start. Looking forward to a more detailed description of your instrument and further results. Regards Andrew

Isn't that a filter wheel and filters? 😉 Regards Andrew

Looks a very good start to my uneducated eye. Regards Andrew

OSC or mono are not intrinsically good or bad they offer different options. Simple, lower cost rgb OSC is a winner. Higher cost and flexibility mono is a winner. Just as with most choices in astronomy it's what you want to do with it and what you can afford that counts. Regards Andrew

Good start. Now up the learning curve. Regards Andrew

In the post you should get it tomorrow. It is powered but the two ports furthest from the PC connection work unpowered. I also included two ferrite cores that you can try on the USB cable and on the sx power cable. They open up with two small clips on the side. If the cable is thin enough loop it through twice. If it works just keep it as I found f two more in my box of cables! Hope it works . Regards Andrew

@Jeremys I always got banding on the down loads. Usb3 uses different chip set to usb2. I will post hub to you to try. Regards Andrew

@JeremyS did you connect the camera before installing the drivers? SX say you should not. If you did disconnect , uninstall and try again. Under device manager is it installed correctly? I never got my sx camera to work with usb3 but I had spare usb2 ports. I have a usb2 hub you can borrow to try if you want. Regards Andrew

@jetstream, not sure I have due mainly to limited experience and observing time. Technically I understand the relation between aperture, magnification, transmittance/refectance, exit pupil and image brightness but am not clear on what you mean by "washed out" do you mean low contrast or illumination or perhaps something else? I have read some reports of refractors giving a colour cast due to a combination of the anti reflection coatings and or the absorption in the glass. However, I have no personal experience of the effect. Regards Andrew

Excuse me no refractor talk on my thread 👹 Regards Andrew

Yes very portable with built in handle. Regards Andrew

No excuse needed Helen. Regards Andrew

Keep pushing Helen, it will make a nice reward. I have been enjoying it. I am rearly just learning visual observation and relearning about the poor local weather. It seems a very competent scope I keep it in an observatory so no cool down issues collimation is stable and very little if any focus shift. Go on you deserve it. Regards Andrew

Look FAB. Regards Andrew

Me too. Regards Andrew

I like it. Dark and brooding . I am sure you could process more out of it but I like it as it is. Regards Andrew

Fine scope enjoy, Regards Andrew

Hallelujah, hallelujah.... (Provided the scopes usable field can cover the sensor .) Regards Andrew

I think after a long discussion on this "etendue" was the key measure. Simply it is the equivalent of the product of aperture (how many photons/s) and usable field of view (sky coverage in arc secs). Provided the scope/detector has the resolution required (which is almost always the case with modern CMOS cameras) this captures the rate of accumulation of information from the sky. It helps balance the multitude of factors ,e.g. aperture, useful telescope FOV, chip size, focal length etc. I commend it to the forum (and it's a French word @ollypenrice 🥂) . Regards Andrew PS Might be better to use aperture^2 x field of view arc sec ^2 for comparing disparate systems.

@vlaiv thanks for taking the trouble to do the calculations on the nebula colour. While it may not be exact given your concerns it does (as you well know) demonstrate that colour can be validated given good calibrated data. Regards Andrew

@vlaiv, I accept that could be the case but it would require a special set of circumstances. Most stars are Red Dwarfs with 3000k ish photospheres and very little blue to start with, however, we could trade ideas forever without more data!😉 Regards Andrew

Why would they be gray? Most star are far from gray and similarly scattering cross section tend to be strongly wavelength dependant so I find it hard to see how they would be gray. I might well be wrong though. Only careful measurement could tell. Regards Andrew

You mainly get drift if your just tracking and mainly rotation if guiding if the polar alignment is out. Regards Andrew

I don't think a nebula will look blue in general. Clearly some do as in the blue reflection nebula where they are illuminated by a hot blue star. What you get depends on the specific type and geometry of illumination and the details of the size of the scattering particles. Dark nebula don't transmit in the visible and don't seem blue as there are no hot stars close enough to light them up. Similarly with the "brown" nebula there don't seem to be any hot stars to make them blue. As you pointed out most star are red. Regards Andrew

Sorry, I updated my post while you were posting this. My issue is what is the "colour" of the light leaving the nebula not what colour do I like. You propose it is due to our atmosphere I that it could just be the nebula. The way to tell would be to look at foreground G2V stars and see if they are changed by our atmospheres you propose. Regards Andrew