michael8554

Not my strong suit Michael

So you stop guiding and revolve the dome when nature calls ? Michael

Those 18mm ones are the same width as my single ones ! Looks as though a previous owner has not fitted the right replacements ! Does your door foul on the lower shutter rail brackets when the shutter is opposite the door ? Michael

Hi Jeremy Interested by your images of the new wheels. Did yours have double wheels originally ? If not, why did you go for double ? One of the wheels on my Mk 1 falls off the track at a certain point, double or much wider wheels would stop that on mine. Michael

http://dslrmodifications.com/rebelmod450d1.html Michael

Given the very oblique nature of the reflections, a Dew Shield might help. Michael

Hi Gasconman If you're only doing Visual, looking through eyepieces, then roughly pointing north will be good enough. PA only becomes important if you want an object to stay exactly in the middle of the Field of View for a long time, as in Long Exposure Astrophotography. You can get very good PA by Drift Aligning with only a high mag eyepiece, ideally one with a reticle to aid centring. Michael

Good point actually, the setting circles are as impressive as the rest of the scope. Michael

I believe it's the other way round - Device Hub has replaced POTH Michael

Must be very early as it doesn't have High Contrast or Ultra High Contrast on the front ring, or a Primary Mirror Lock on the back. But the pin on the back may be part of a DIY lock. Michael

Hilarious...... Michael

Your link was to a Multispeed Handset, so I assumed low speeds were available. 8X might work, but I'd suggest starting with the lowest setting and find one that gives 12 to 15 steps in the calibration. Michael

The concept for modifying the handset is that you attach a wire carrying the guide commands to a left and to a right slew button contact. So you only need to identify the correct contact with a test meter, the rest of the mod should be as in the Dual Axis mod. Michael

The legend says "Up is -85.5 degrees E of N". I think this means that RA is running from top to bottom of the image. If so the drift is in RA. That means it's not due to poor PA, that movement would be in Dec. Simplest explanation would be slop in the image train, since you say it varies the sky position. The Belt Mod removes Periodic Error caused by the gearbox, but the Periodic Error due to the worm and wormwheel remains. However I seem to remember the worm period is typically 480 seconds on these mounts ? So 10 to 15 minutes would be 2 or 3 cycles, are you sure it's not showing the full drift after 8 minutes ? If you don't want to use the mount PEC you will need to guide if you want longer exposures. But all this assumes I'm right about the image orientation 🙂 Michael

Does your mount have metric or Imperial Allen screws ? Michael

Some sort of tiny spring clip for holding the cells in place has become displaced ? Try gently rotating the scope end-for-end, and listen for rattles, or see if it has moved. Michael;

Hi Lee If you have Polar Aligned and it's "bang on", then your Lat setting must be correct. But to get to the bottom of these issues you need to quantify your PA figure, "bang on" is meaningless. You say that Jupiter "drops out of the eyepiece" - is that in RA or Dec ? A RA drift could be the Periodic Error in your mount. A Dec drift could be the mount shifting due to loose mesh between the worm and wormwheel, offset balance slightly to take up that slack. Michael

Ah John you really ought to get a non-motorised dome like mine. Think of the exercise you get from rotating the dome every 15 minutes or so, and scraping your back on the doorframe in the process. Oh and trapping yourself inside the dome if the shutter is opposite the door, as in that position the lower shutter rail brackets prevent the door opening! I could raise the brackets of course, but then the shutter wouldn't open past the zenith. And the muscles you develop trying to pull the shutter closed if it's past the zenith. Maybe not with your back. Mine's the very first Pulsar 2.1M version Try as I might I could not get the wall or the dome to be circular when the segments were tightened together, before bolting to the concrete. So one of the wheels falls off the track at a certain point. Doesn't help that the wheels are on the outside, so nothing to stop that - moving one wheel inwards pushes the opposite one out, so that one falls off the track instead. I believe the newer ones have the wheels inside ? Not Pulsar's finest hour, but I wouldn't be without it. Michael

Try DSS without the Master Dark and Master Bias Instead use the Master Bias as the Dark. (A common DSLR image technique, but needs Dithers to work well ) But it could be that your 1 minute exposures have hardly any more data than your Darks. Michael

Here's a random shot of an AZ-EQ mount and Reflector telescope. The eyepiece and finder are both in easy to reach positions:

Here's a calculator: https://astronomy.tools/calculators/ccd You enter the pixel size and focal length and it calculates the image scale, 1.07arcsecs/pixel and 4.43arcsecs/pixel That a ratio of 4.1 : 1 By coincidence the Canon 1100D and the Orion Autoguider both have the same size pixels, 5.2 um So in this case only it's easy, the ratio of image scales is simply the ratio of the focal lengths, 242mm to 1000mm, or 4.1 : 1 I'd expect that to work for you. Michael

If advertised for Canon EOS it will fit. They have accidently sent one for a Pentax K I expect. Just get a swap from them. Michael

You may not have realised that many of the M101 images you've seen all started out looking like your image. Then the Image Processing magic happened. Agreed on guiding as a good next step. An OAG will be less expensive than a guidescope, rings, mounting plates etc, and will be suitable for almost every future setup you get. Michael

NEOWISE was really good while it lasted, the comet we've waited years for. Michael

Hey Joe, (Where You Goin' With That Telescope In Your Hand ..........?) :-} What length are your exposures ? Are you using the Recommended settings in DSS ? Michael