Rusted

Great stuff! Thanks!

Thanks. The seeing went off for the rest of the day. A late chance of better seeing conditions produced these just above the trees at 18.44[CET]. Yet again I risked the use of the 2.6x TS GPC for increased scale. Cropped to 400 and then resized to 600. I think it worked despite the "wobbly" conditions!

Thanks for your helpful advice. I was referring to the small size of the finder bodywork rather than the dot. A green spot or cross sounded like a much better idea for daylight use. Strapped to a spotting scope for digiscoping on featureless lakes. Or homing in on planets in my 6" refractor once I have fitted a camera and/or a Barlow and completely lost focus. More homework definitely required! Thanks again.

Thanks Gordon. The Pulsar would seem to have a 75mm/ 3" flange on the outside to rest on the roof. I shall have to make a plywood ring to sit on top of my existing 2"x10" dome base ring on top of the octagon. Height adjustment in a push-pull arrangement should even out any minor inconsistencies in level. Still waiting for a price for a 40T, 40' container lorry to try and deliver two large pallets down our very narrow drive. Then it would be a matter of waiting two months while I collect summer rain inside the plywood dome. Production has been set back by the virus and I wanted the sage green. The local tarpaulin supplier and project builder cannot supply sage green. I'd bought a straight, Bosch Pro heat gun in anticipation but the PVC dome cover looks like a non-starter.

Hi, I have never seen a red dot finder in the flesh. Let alone owned one. So you may safely assume zero knowledge. I need some quick advice from direct, hands-on experience. I thought I'd get one to speed my aim without fitting a proper finder. Really don't want to fit one one right now. [It means major dismantling, tailpiece and baffle removal, drilling main tubes and re-balancing.] Do these things work well in bright sunlight? This is important to me. How small do they go? This is also important to me. Flash shoe fitting on a 4/3 mirrorless DSLR small? How accurate are they? Moon's width or less? Does quality vary much between makes and/or price? Any strong recommendations from direct personal experience in the "bijou" category? Grateful for any advice so I can put in an order ASAP. Thanks.

Thanks. I tried pushing it in ImPPG and PhotoFiltre but nothing I tried made it look any better.

Milky sky with some cloud: 71F. 17.06.20 Using the PST BF for lower gain. 2.6x T-S GPC for increased scale in early, steadier seeing. 16.06.20: The AR slides off the face of the sun.

Newton's rings are better seen with near parallel light normal to the surface being tested. Monochromatic light is required to emphasize the rings. That is precisely how large optical flats are/were once tested in a simple partially reflective rig. H-a and a stack of plane-parallel surfaces are a perfect scenario for creating NR.

Clear and sunny all day here. Captured the disappearing AR early this morning. Then saw nothing on Gong. So I never went back.

Thanks.

Thanks Dave. I missed most of the fun due to cloud over the last couple of days. Now I'm being blown away by 30mph gusts! The whole dome is shaking! The seeing is actually quite good when the telescope stays still. The wind must be mixing up the usual thermal mess. Here's a couple of later ones. I've lost the auto time stamps in SharpCap. Tried pushing all the buttons in Setup >Filenames but they won't come back.

Easterly gales straight into the dome. Racing clouds from the east. Can't undo the PST sweet spot today. Lost Wifi. Losing my marbles. Etc. Etc.

My 6" f/8, with internal 90mm D-ERF, produced a fiercely hot, reflected focal point just outside the objective. An ideal spot to hold your face when peering into the OTA to check for morning dew! I literally set fire to a temporary cardboard ring white experimenting with stopping down. Do these "big name" manufacturers approve of having a bonfire in the dewshield? Break the piggy bank, on a full aperture D-ERF and protect your investment [and your eyes!]

I use a full aperture 160mm Baader DERF + the 35nm Baader + a Beloptik KG3 in my 150/10 H-a PST mod. Why? Because I might cook my expensive ZWO '174 camera with a sub-diameter ERF. I cooked my ASI120 using a 90mm Baader D-ERF well inside focus of a 150/8 PST mod. After the PST etalon, ITF + BF5! A hot beam continued after the 90mm internal D-ERF! Hot enough to remove my hand rather quickly at the open focuser. Despite my extra filtration, my ASI174 soon reaches 40C on the SharpCap thermometer. 48C after a couple of hours of tracking the sun in summer. [Sun willing.] An abundance of caution is desirable if you want to do visual with a larger aperture like your 140. Why not explore a PST mod? Stunning views in H-a both visually, binoviewing and for imaging. Though you still have to afford the bigger D-ERF if you want to be safe. IMHO.

I wonder if T-S or Baader do an adapter ring to go between a 3m Ø octagonal building and a 2.7m Ø round tartan dome? It is all very well making a plywood "adapter ring" but I'd still need a giant bell washer to throw the rain outwards. Or would I? The full height [walled] domes are simply placed onto a flat concrete foundation and silicone sealed. Does anybody here have any direct experience of fitting the short wall Pulsar to a flat roof?

I wrote tartan in my response to Dave and then decided to change it something else. My having enjoyed only a few, brief years in bonny Scotland, as a bairn and that was in the last century. I wonder if Oor Wullie is still alive? His bucket must have <cough> rusted away by now! 👴🏻

Camo? What about a tin of Union Jack? Suits you sir!

The Medium. They have improved the design to contain the full width of the rubber strap. Normally it wouldn't matter but I needed a pipe to get enough leverage to break the PST red locking stuff. The pipe helpfully contained the strap and handle and provided more leverage. The PST body was held down with G-cramps. It was a hell of a struggle despite my decades of practical experience.

Thanks for the idea but I'd have to find a Danish stockist of a similar product. With no guarantee of long term sealing of such a flexible structure it might be just another waste of more money. I am seriously beginning to think that I should have started with a Pulsar dome instead of building a white green elephant. Unfortunately I was swayed by owning a 7" f/12 which I later, optically folded anyway.

Probably improve the design where the strap falls out of the side of the slot if you crank it with a four foot length of scaffolding pipe...

I have just discovered that Pulsar offers "sage green." It pops up on their FB space. I thought it was just a trick of the light at first. Do you think The MD would notice if a did a quick swap with my "fish tank?" EDIT: The lighter "SAGE GREEN" IS THE STANDARD GREEN FOR PULSAR DOMES other than the NORMAL WHITE. Apparently, the darker "Forest Green" was discontinued some years ago. I didn't know that.

A vice crushes opposite sides of any round thing into an oval. Which greatly increases the friction! Can't recommend a "missus" or a "hubby" either. Not just for unscrewing a PST component. Though I have heard rumours that "they" have other uses.

Wait in the queue mate. I was here first. And you're right of course.

Wit of man? WIT OF MAN? A few leaks? I have the equivelant of a town's drinking water tank up there! Hipsters will be fighting to buy it up to convert to a <cough> highly <cough> des. res. Just to get on a TV "challenging, grossly undersized, architecture" show. But I have a plan.