iantaylor2uk

The small jpg files are the images that are shown on the tablet during imaging. The FITS files are the full sized images used for processing.

I'm not sure there is any argument - for wild camping, surely you need a tent! If you are out simply observing and using a telescope then of course it isn't wild camping.

Yes - it just relies on the self centring action and locking - there is no way to screw it into something on the telescope

I use the Hotech flattener on my WO 81 mm refractor and on my Tak TSA 102 mm refractor. It says on the flattener it works on telescopes from f/5 to f/8. Backspacing to sensor is approx 55mm. I have found it to be quite good. It also has a self centering action - you screw it in and that forces 3 rubber bands against the inside of the tube so this helps avoid tilt.

I think it would work but it would take ages to calibrate compared to modern guide cameras. I tried this once in the past.

I once had one of these and found you could roughly collimate in daylight by adjusting the collimating screws on the back until everything looked symmetrical when you stood about 6 feet or more in front of the scope.

If you're looking at 6 amps, delivered at 12 volts, then that's 72 watts. If you want it to last 6 hours then that is around 430 Wh. You can get a Jackery 240 Wh battery which I've found is good, and there is also a 518 Wh version. I don't think the mount will take much current when tracking. I think the mini PC, the camera cooling and the dew strips will be the power hogs. The other thing to remember is that batteries don't like extreme cold (less than -5C) in my experience.

Well to a good approximation they are both inverse square laws so the main difference between the forces is the strength of the coupling - in the case of gravitation this is the gravitational constant G, and in the case of electromagnetism it is sometimes known as Coulomb's constant. The other difference of course is that in electromagnetism charges can be positive or negative so you can get attraction or repulsion, whereas in gravity masses are only positive, so you only get attraction. I would have thought it if you ask an AI to compare the two forces it would simply say what their ratio would be - I would be very surprised if it explained the nature and origin of the forces.

I thought it was pretty well known (to physicists at least) that the electromagnetic force is around 10^40 (ten to the power 40) times stronger than the gravitational force - not sure why it would need such a long and detailed answer.

I think most people that use the ASIAIR use the USB 3.0 64 Gb thumb drive which comes with it for storage rather than use the SD card and so transferring images over to a PC for processing is straightforward.

If we take a step back, my understanding is that the ASIAIR Pro and its variants are marketed at ZWO users, as an aid to increase productivity since it can be used for polar alignment, auto-focusing and auto-guiding, and you can be up and running to take photos in less than 10 mins or so. This is very attractive to many users that already have ZWO cameras. In addition, you don't need a laptop or PC outside (most users I think will be outside rather than have remote control) and can just use a cheap android tablet. So the fact that it only works with ZWO equipment is a feature, rather than a problem. If users don't want to use ZWO equipment then they can try to reproduce the functions of an ASIAIR Pro with a mini PC and various other bits of software but I would think it would take quite a bit of effort to get it all working flawlessy everynight and it would be a pain to have to update all the different bits of software at different times, as opposed to the AISAIR where the front-end is updated and everything just works. I'm speaking as someone who used to use a laptop at the scope for autoguiding and imaging, and the simplicity of the ASIAIR, and the much tidy cabling, has drastically increased the time I can actually take photos, as opposed to "faffing about" getting things working.

I think some of the above "solutions" depend on the type of CMOS camera used. I use a ZWO 071 camera and have no problem with much shorter flats than 3-5 seconds, and simply use bias frames rather than dark flats, and don't have the problems you seem to be having.

I know some people say flat frames should be a few seconds exposure but I have found with my ZWO 071 camera they are usually only around 50 milliseconds or so with a UV/IR filter, and around 300 milliseconds with an L-Enhance filter. This is with a flat light pad over the top of the telescope. I tend to use bias frames rather than flat darks, and these are usually taken at the shortest exposure your camera has, with a cover over the telescope. You can re- use the bias frames from one session to another.

Not sure if there is any value using an S-curve. These have the properties that the gradient is zero when x=0 and x=1 which may or not be beneficial. I've just published a paper on using such curves to predict friction (the paper is open access if you want to read it at: https://www.sciencedirect.com/science/article/pii/S0301679X2200408X) Based on the work in that paper you could try a curve such as: (1+(1/(cx))^k)^(-a) where k c, and a are constants (with c being 10 or 100 for example).

I tend to use high gain (200 on my ZWO 071) with an L-Enhance filter (and with this filter I would usually use 2 or 3 minute exposures). If I'm just using a UV/IR filter I will often use 90 (unity gain on the camera) and 30 or 60 second. Agree with the above comment though, in general if you increase the camera gain it would make more sense to decrease the exposure time, or at least check nothing in the image is saturating.

The geometry of space time at the smallest length scales is not known. If space time is emergent, as is thought to be the case, and is generated by simple rules, it could well be fractal.

I doubt very much anyone born before 1900 would have been able to imagine the transistor.

You don't need to imagine angles, as they are real!

Sorry no more recent updates - i've mainly been using the CT8 for visual, as I've been getting great results from my Tak TSA 102 refractor, which is a similar focal length. Was also getting some strange halos on some of the stars with the CT8, not sure if that was the L-enhance filter or something else. Once the nights get shorter in the UK I may try again with the CT8 as it's lower f ratio is definitely an advantage.

Can't they be reported to trading standards?

The 290MM mini would be far better for guiding than the 120MM mini in my view.

I wouldn't recommend using a hairdryer - there is a possibility you could crack the glass

I'm quite into maths - it is fairly straightforward to show that the infinity of natural numbers (i.e. integers) is, somewhat surprisingly, the same as the infinity of fractions, and it is also possible to show that the infinity of irrational numbers is a bigger level of infinity. It is also possible to build even greater levels of infinity from these first two levels. One of the biggest questions in maths is whether there is any other infinity between that of the integers and that of the irrationals, which as far as I know is still unknown (it is called the "continuum hypothesis" if you want to do a google search). I'm travelling to London next week so this is something to watch on the train. Thanks for the heads up on the documentary.

For anyone that may be interested, I'm giving a talk tomorrow evening at the Chester Astronomy Society's members evening on astrophotography. A pdf version of the talk is attached. Astrophotography journey 2022.pdf

I use a hotech SCA 1x flattener on my Tak 102 TSA and it works for refractors between f/5 and f/8