Rusted

Back for an afternoon imaging session.

A slight tilt somewhere might help relieve the Newton's Rings. Some cameras are more prone to NR than others. Some filter systems are more prone to it in H-a. Monochromatic light and the camera's protective sensor cover will do it sometimes. Uneven lighting and patchy detail are due to the so-called etalon sweet spot with larger apertures. I rotate [clock] and mark my Blocking Filter housing relative to the PST etalon. Rotate your BF and aim for darkest, most even and detailed image. Electrical tape, on one edge of the BF, is aligned with the bit of tape stuck on the etalon housing. I find it helps. If your PST mod is still in its original form then you may not be able to play with rotation. My 150mm PST Mod uses the popular AOK Swiss PST Etalon Housings. One front and one back.

Drilling holes for lightness? You must be a cyclist.

Thank you for your kind message. I only intended to explain my absence. Imaging helps to fill the empty hours. Far better than sitting about moping.

I am getting back into imaging after suddenly losing my wife to cancer. The seeing was poor today but I captured AR2993/4 near the NE limb. The inverted image shows amazing detail compared to the normal image.

I built a 7" f/12 folded refractor using 5" and 4" flats. Do NOT undersize the folding flats. Do NOT try to make the folding angles too acute. Both will lead to serious problems with stray light. A narrow, folded refractor is EXTREMELY difficult to baffle effectively. Draw your full aperture light cone on lining paper and cut it out. Now fold the paper cone where you want your flats to lie. Allow a generous field diameter at focus.

Er.. was this taken at the equator?

Wise words indeed. The cost in time and materials for DIY plywood domes is terrifying.

Nice! An excellent idea to coat it in GRP. My marine plywood dome leaked like a sieve after only a couple of years. Too expensive and inaccessible for coating it once in place. The colour is an interesting choice and suits the environment perfectly. Visually far better than white. The only downside is likely to be daytime warmth, in summer sunshine, if you do any solar. Side note: The long shanks padlock is wide open to crowbar attack. Discus? Side note 2: Coach bolts on the door hinges will avoid easily removable wood screws. Your back garden may be inaccessible to 2-legged vermin.

ImPPG is indeed free and very popular with solar imagers.

Stuart, Great minds think alike! I'd say you are nicely on band for H-alpha. Nice wide spread of detail too. You just need a bit of processing in ImPPG to get more detail and contrast: The images was slightly sharpened before I processed it. So I've made it too dark and grainy. This wouldn't happen going direct from AS!3 to ImPPG yourself.

If you use an app like this: Solar activity you can arrange your wonderfully crisp spots in the correct orientation. I know, I know. I'm such a pedant! Just passing it on. 😇

Thanks Pete.

I can hardly believe I managed to extract a single image from the recent seeing conditions. Wall to wall sunshine and it keeps defocusing. Image too soft to focus in [less than] SharpCap. Thermal wobbles all over the place! There's supposed to be a light bridge on AR2960! Stop laughing at the back!

Hi Nigella, I tried to warn you about overdosing Astrocat on ImPPG. Don't even get me started on black cats and thermal issues with solar imaging! A tabby is your best bet pet for both day and night imaging. Best of both worlds!

I think a more accurate term would be "polar altitude adjuster." [Or PA thumb screw] But then I'm a pedant. Not to be confused with peasant. Which is also true.

Ideally an equatorially mounted telescope is balanced around a point at the crossing of the mounting axes. If it were not balanced, then the nose, or tail of the scope, would rise or fall. It shouldn't do either. If it were not balanced then the counterweights, or the OTA, would rise or fall. Again it shouldn't do either. This image shows the crossing of the axes. Polar [RA] and Declination. The vertical line represent a perpendicular dropped from the crossing of the axes. The horizontal line shows the offset [or distance] of this perpendicular line from the tripod head. This offset represents a turning force trying to tip the tripod over. It also applies an increased force against the altitude adjustment screw.

Some of our local DIY, big shed stores sell assorted thumb wheels and knobs. Take along your original thumb screw to ensure the threads match. Balance is just as important to an altaz as it is to an equatorial. That's an awful lot of stuff perched [un]balanced high on top of a very little mounting. IMO. Worse, the mass is offset relative to the very narrow base. With all mountings it is the smallest cross section which matters under load. Your whole system is a compound pendulum. Look it up. I'm sorry, but I really wouldn't start from here if you want steady support. Which is exactly what that altitude screw is trying to tell you. In case of doubt: I have been overloading telescope mountings for over 60 years.

Barry rang me in the middle of dinner to repeat the nonsense he said back then. My dinner was getting cold. So I hung up. EDIT: I recorded the wheel numbers on my blog. 567 & 568. Making them consecutive.

An excellent set of images!

I have both a Lacerta 2" wedge and a Lunt 1.25". Both give excellent views and are also used for imaging. The Brewster angle can be a problem for visual use in tight spaces. I can't get my head behind the Lacerta wedge at certain solar altitudes. Because my dome base ring gets in the way. Others won't suffer from this problem. A solar foil filter protects the telescope's innards. While a wedge allows the full, focused heat of the sun to pass right through the telescope. This requires much greater care at the eyepiece end to avoid injury or even fire. For example: A plastic, focuser dust plug will readily burn if you have removed the wedge for safe storage. As I did only recently. When I safeguarded the instruments due to a dangerous storm warning. It is safer to have a cap for the dewshield until you are certain you have the wedge properly fitted. A secure, opaque cap for the finder too! The rotating polarizing filter is a great wedge accessory. Well worthwhile to set comfortable viewing brightness. Just remember to minimize the light cut if you decide to image. Or your exposures could get very, very long!

I have been looking back though my blog and corrected the delivery date of the Beacon Hill worm wheels to August 2016. https://fullerscopes.blogspot.com/2016/08/2-shaft-mouting-pt24-wormwheels-arrive.html Once the worms and wheels were actually fitted to the mounting they produced a very loud, "graunching" noise on driven slews. This was due to the extreme roughness of the machined surfaces of both worms and wheels. This was after I had scrubbed the teeth with a fine wire brush and paraffin. I had no plans to embed the obvious grit in the "precision" machined surfaces. The toothbrush had zero impact on the embedded filth in the teeth! It was completely impossible to run the worms against the worm wheels dry. [Without lubrication] There was far too much friction! Having been told by Barry Watts not to use anything but oil to "lap them in" I resorted to hours of free running the RA worm against the worm wheel driven by an en electric drill. I tried an assortment of fine abrasives [like Brasso which sprayed everywhere.] All without much improvement in the hideous and loud "graunching" noise of the rubbing surfaces. Not only were the worms rough but they could be heard to change their racket with every revolution. So the brass worms [NOT stainless steel] were actually eccentric. The worms are glued onto the miserably short, steel shafts. Solvol Autosol is a polishing paste for chrome. It has a fine abrasive quality and stayed in place during the polishing operation. This finally helped after countless hours of "lapping." I am normally a polite person. At the time I was so ashamed at having been sent these inferior products that I went into full denial mode. I deliberately hid the tooth defects in all my blog images. I did not show the filthy, black teeth on arrival. Nor did I mention my endless mechanical problems on my blog. Which was a complete disservice if anybody followed my lead and bought worm and wheel sets from Beacon Hill. And as still recommended by NON GOTO AWR[Tech] UK. The vendor of an expensive and noisy stepper motor Goto, drive system. Which has never found a single object in all the time I have been using it. Not the sun, the moon nor any other object. Not once in ~5.5 years! Barry Watts of Beacon Hill Telescopes is the master of transparent excuses. No doubt a skill polished over lifetime of failing to supply on time. His [quote] "agricultural" mounts are the stuff of legend. For failing to arrive as promised and being more of a "project in progress" when they finally do get delivered. He failed to get me to accept 1" shaft holes on smaller wheels after a month of waiting. I had ordered 50mm in 14" and 11". It took another month to source the junk I was sent. No doubt out of his octogenarian machinist's scrap bin. With 60mm bores not the 50mm I had ordered. Which is what he finally sent me. His failure to clean the filthy worm wheel teeth is ample proof of his completely casual attitude to his paying customers. He had wrapped the circumferences in protective pipe insulation. Was this just another ploy to hide the hideous filth/truth? His flowery descriptions of his "products" are the stuff of complete and utter fantasy. These same descriptions clearly break UK consumer laws and have remained unchanged for years on his website. He maintains this as a sales and advertising website but denies being "online." "The finest worm wheel sets available in the UK." Not by a light year!

Thanks, but it looks like a poster painted with a coarse brush to my eyes. I tried stopping down to 100mm [from 150mm] but it didn't make any obvious difference. It must be the seeing conditions. At 55N the sun is still struggling for altitude.

Thanks for your encouragement. I see a strange sharpening or graining effect after processing. Here's my last image of the day. 16.08 [CET] Posted full size. Does anyone else see a vertical texture overlying the image?

I was wasting my time all morning with strangely grainy images. After lunch the first image was fine. Then it all went bad again.