Seelive

My first telescope became the finder on my third and last. This was taken around 1982, sadly I no longer have either nor the observatory they were house in.

You can buy cases specifically designed for them.

Search for passivating stainless steel, that should give you some possible solutions.

It's certainly easy to capture but, like M31, with such a large dynamic range, I would suggest neither are particularly easy to process to get the full details out of them (but of course they are probably two of the easiest DS objects to capture an image).

If you're using DSS to stack the images you could put the 60s images in one group and the 15s images in a second and then use the Entropy Weighted Average (HDR) stacking mode. I've used it sucessfully with M42 to show the Trapezium stars but I used 4 different exposures (180s, 60s, 20s and 7s) so I'm not sure what the result would be with just 2 different exposures.

Never had a problem with mine, I use it for imaging with a set-up of a similar weight.

It's a very star rich area and removing the stars does somewhat retract from the visual beauty of that area of the sky.

DSS scores images on a number of factors but I have no idea what the weighting factors are for each (a question for the DSS forum). The upper image appears to have round stars across the whole image whereas the lower image seems to have elongated stars in the corners. What does DSS report for the the FWHM value for each image?

Not exactly sure what you are trying to achieve but there's an old article on a simple method to the determine spectra noise published in the STECF Newsletter #42 back in 2007 that can be downloaded from https://www.spacetelescope.org/about/further_information/stecfnewsletters/hst_stecf_0042/

Let's not go down the ironing route again please 😆

Flats are arguabley more important that darks if you are suffering from significant vignetting (and are much quicker to obtain than darks). As you used a fixed camera lens then, since the optical alignment won't change (and assuming you haven't sprayed everything in dust since taking the images), you can still create them after the event and then apply them.

I hadn't seen this whilst I was typing my last reply. As suggested by Peter, swap them around and see if that solves your problem (but still don't expect a 'solid' lock!)

The design of the mount is not particularly optimised for latitude adjustment especially near the limits. Even at 53', unlike the azimuth screws, they do not appear to 'lock' against each other. I thought that it may be due to the screws being nylon tipped but I now suspect it may be due to bending of the screws (there are plenty of threads on here about replacement altitude screws for SW mounts). I would suggest slacking off the right hand screw as far as possible, move the altitude by hand to just less than your latitude then adjust to the correct altitude by screwing the right hand screw back in. The left hand screw can then be screwed in as far as possible to 'lock' to position. When polar aligning using the polarscope, small adjustments of either screw are obvious but as I said, they never seem to solidly lock against each other as you would expect.

According to the manual it should go down to 15'. Try removing the right hand screw (in you photo) completely and tilt the mount down by hand too see how low it will actually go. When aligning my polarscope, I was able to go a lot lower than 30' so that I could easily view through the polarscope with it being near horizontal (infact I had to remove the counterweight shaft so that it didn't hit the north tripod leg).

Were you using a filter of some type? I certainly wouldn't expect any reasonable straight optic train to create that sort of 'reflection', dispite how bright nearby stars are, and it's certainly not something I've ever experienced with a similar field of view image of the Horse Head. Prehaps you were very unfortunate to just happen to have Alnitak aligned on an optical defect of some form.

I admire your perseverance - that PCB was never designed to take any of those diodes 🔨😊

Have you gone through the file list displayed by DSS and compared the size of all the files, especially the lights and masters? I had the same error a while back only to find out than an update to DSS now registered my lights 2 pixels smaller in one axis so rendering my previously registered TIFF masters unusable (I just reverted to the previous version I was using).

I can only assume the 1N5822 Schottky fast recovery diodes were chosen because the PWM frequency used in the design is in the 10's of kHz (which in my opinion is unnecessarily high for a dew heater). My homemade dew heater controller runs at around 50Hz and quite happily operates using 1N4001 standard recovery diodes for protection of the MOSFETS from any inductance induced voltage spikes.

The P6KE10A are transient protection diodes, totally different beasts from the 1N5822 Schottky diodes.

The land (or pad) is the annular ring of the PCB pad surrounding the hole. I suppose the problem in drilling out the hole is that you won't be left with a sufficiently wide land for a reliable soldered mount and the manual enlargement of the hole with a hand held drill could result in stripping what does remain of the land from the PCB. I would only drill the hole out if it would be leave at least a 0.5mm width annular ring.

If it's just a double sided PCB then there is no problem with drilling out the hole providing there is still sufficient land left on each side of the PCB and it is soldered on both sides (the solder won't flow through the hole if the through hole plating is removed). A problem would only arise if the PCB had internal layers that were connected to the holes.

'In principle you want to your guide star to be relatively close to target for best performance' To be honest, I think that was what I was alluding to.

1. No, you can theoretically guide on anything. The only factors are the accuracy of your polar alignment, the focal lengths of your imaging/guiding systems and the guiding accuracy of your chosen guide software (I wouldn't rely on accurately guiding on an object near 0 deg declination using Polaris as a guide star 😆). Polar alignment errors will result in field rotation that will be exacerbated by the ratio of the imaging/guiding system focal lengths and the accuracy of the guide software. In normal circumstances, if the ratio of the imaging/guiding focal lengths is not too excessive (eg less than 5:1) and 'reasonable' exposure times are used (ie not hours) then it's unlikely to be a problem. 2 Looking at replies that have been posted whilst typing this, it has already been answered.

Only the 'SIMPLE' theme works on my phone, the other 2 options just result in 'hang-ups' or crashes. The chosen theme appears to be reflected on whatever device you use and since I could never scroll down to the bottom of the page to change the theme before it crashed on my mobile, I was able to change it from my PC. Now I don't have to retreat to the depths of darkness to view the forum 😆

To see what a really dark sky looked like combined with the phenomenal backdrop of the southern sky Milky Way from the deep outback of Australia when I went to see Comet Halley in 1986. Unfortunately Comet Halley wasn't the most impressive object visible.