iantaylor2uk

Agree with the last post. When I first started 20 odd years ago, we had sensors that were 10 times smaller and mounts without goto. It took ages to find objects. Also you had to use a laptop and there were cables everywhere. Using an ASIAIR mini pc controlled by an android tablet means I'm up and running in 10 mins and it usually just works. Some people try to do imaging with a Mac PC - don't do this unless you want heaps of hassle.

Your name and address, for a start. If you're Rolf Harris (is he still alive?) you probably won't be accepted!

This is how it works at this unnamed club as I understand it. You can go to 3 meetings but if you want to go to more you then have to join (or not).

I doubt that they are assessing you at the meetings. I think they will simply assess you on your application form, and I doubt you will need to put any of those details down on the form.

I think you make the good point that the regulations on what clubs can and can't do have become much more onerous over the last 10-20 years or so, and in my view, any well run club should have the ability to decide who can be a member, and also to have the ability to expel members for unacceptable behaviour. I doubt these powers are used that often but any people that say they shouldn't exist, have probably never served on the committee of a club (astronomy or other).

That sounds more like the masons (sorry if I offend any masons on here but as it's a secret society no one is likely to admit to being a mason!).

I think to be fair, it seems as if you can attend 3 meetings, for free, without being a member and it is only if you want to attend any more meetings that you need to apply to be a member. I would have thought that if any under 18s attend the meetings it is very sensible that the committee can decide whether to accept applications or not.

I would recommend the FRA 300. I know you have the FRA 400 and could use a reducer, but from my point of view the whole idea of these short focal length refractors is not to introduce any more glass, so I deliberately chose the FRA 300. I have matched it with a ZWO 071 MC Pro camera - although this is not the latest tech it does have quite large pixels for a CMOS camera (4.78 microns). I have found this to be a pretty good combination, and I consider f/5 to be fast for a refractor (my other one, a Tak TSA 102 is f/8!). I have also had some great results from this combination too.

I should have added in my original post that I too am a Chartered Engineer, although I got mine through the Institute of Physics! I think enough posters here have made the point that simple observing (either visually or taking photos) IS science and so we are perfectly entitled to call ourselves astronomers. For those who for whatever reason choose not to, does this mean you don't join astronomy societies?

Not sure I agree. An astronomer is someone who does astronomy, which is what we all do. Calling yourself an astronomer doesn't imply you are doing research. Those who do such things can call themselves professional astronomers if they wish, but I think most of us (and most of the public) regard ourselves as amateur astronomers and we're not misleading anyone in any way and we don't need to justify it either.

I use an rst-135 and guide at either 0.5 secs or 1 secs, and the guiding is usually well below 1" but will depend how good polar alignment is and what load is on the mount. The mount is in an innorel RT90c carbon fibre tripod.

You could argue the room would get brighter. This is because photons hitting the curtains will be absorbed by the curtains (and effectively lost) which will cause the curtains to heat up slightly. However, when the curtains are open, as others have pointed out, some of the photons will be reflected back into the room. I think the argument that more photons are lost when the curtains are open is wrong, because those photons which are transmitted through the window (and effectively "lost" from the room) would have been those photons that would have been absorbed by the curtains (and also "lost" from the room)

Not far from you in Chester, and I also managed my first DSO's of 2024, namely M45 and M33 (photos posted in DSO Imaging part of forum), although I only imaged from around 6 pm to 11 pm as I wanted a good night's sleep!

Managed a couple of quick photos last night, which was very clear, but also very cold. Took 240 thirty second images of M45, and then M33 (which was fairly close to the moon). I stacked the best 90% of the images, and used dark, flat and bias calibration frames. Stacking was with DeepSkyStacker, and then I quickly used GraXpert to get a final processed image. Fairly pleased with the M45 image but probably need a lot longer on M33. The camera used was an ASI 071 MC Pro and the telescope was an FRA 300 (focal length 300 mm, objective lens diameter 60 mm). I also used an IR/UV filter.

I think the best way to think about it is that the centre of circle A is a distance 4r from the centre of circle B (where r is the radius of circle A) .

Very nice but not sure you need 5 min exposures

Actually I think the journalist may be correct - cosmic rays can generate Cherenkov radiation - this is where charged particles travel faster than light in the specific medium they are travelling in. The speed of light in air is very slightly lower than the speed of light in a vacuum so this could potentially happen.

Welcome to the forum, there's a few people on here in and around Chester so not too far away from you. Hope you manage to get some good images with your set up.

Some astrophotographers cool their cameras down to -15 C or lower, whereas others only cool to 0 C or -5 C. There seems to be some confusion as to what is best. I think this arises becauses manufacturers tend to plot the dark current on a logarithmic vertical scale. As an example, see the graph below (from ZWO) for the 533MC-Pro OSC. Now it may not be immediately obvious, but the vertical scale is actually logarithmic. The peak dark current, at 30 C, is 0.125, whereas the smallest dark current, 0.00013, at -20, is almost 1000 times less! I digitized the graph below, using the very useful website https://automeris.io/WebPlotDigitizer/ and replotted the data on a linear scale - this is also shown below too. This is why I personally tend to use 0 C or -5 C, and don't tend to go to lower values - I also live in a Bortle 6-7 region, so the light pollution levels will usually far exceed the dark current from the camera. Hope this is useful.

If you plot the data on a linear scale rather than a logarithmic scale you will see why 0 or - 5 C are plenty low enough. Usually light pollution swamps the camera noise in the UK.

Only reason really is I run my rig off a battery, so it will last longer if you cool at zero or - 5 C. The noise is so low in this camera it doesn't make much difference really.

Looks good. I personally wouldn't bother cooling to -15 with this sensor, -5 or even 0 C should be fine.

I'm pretty sure people have fired single photons at double slits to show that photons only interfere with themselves (rather than other photons) to create the well known diffraction pattern associated with the wave like behavior of photons.

It's good to have competition in this space. Looks like a direct competitor to Askar''s FRA 300 f/5 scope, which I've been very pleased with.

Good clear night yesterday in the North West of England. I managed around 4 fours of imaging of IC 1396 using my ZWO 071 MC Pro camera on an ASKAR FRA 300 f/5 refractor. The images below are the result of stacking 108 two minute exposures (gain on camera was set to 200 and sensor cooled to 0 C). I also used an L-Enhance filter. One image shows the full field of view, after initial processing, whereas second image shows a cropped version, after a bit more processing (I mainly used GraXpert, Nebulosity 4 and Affinity). Autoguiding etc was managed using an ASI Air Pro on my RST-135 mount.