Rusted

The better seeing was short lived again. Chalk smudges coming out of AS!3 Only ImPPG could tidy them up. Using the T-S 1.6x Bino GPC again. The more northerly disturbed region is now huge!

Excellent set of images. Well done!

Thanks. I have just discovered a blind spot in my thermal deliberations. My large, pitched, shed roof is right beside the observatory on the east side. I have measured the sunny side of the roof at 50C! Eek! It's no wonder my seeing goes off so quickly as the sun rises! I'm thinking of replacing the tired, old, dark red, corrugated, fibre/asphalt. [Onduline.] Probably choose white painted, corrugated steel for lightness Though I have no real idea how cool that remains in practice. I'm just guessing as to its reflectivity in the infra red. Update: White painted steel is very efficient compared with most other materials: Solar reflectance up 80% and emissivity about 0.9.

Thanks. No idea what was causing the noise. Probably thermal? I am experimenting with shading the telescope objective when not actively capturing video. The ASI174 is showing 39C after not capturing anything for half an hour. So I have also closed SharpCap. The cloudy conditions are giving me time to try stapling some white shade material on the open shutters. I was seeing 44C on the shutters. Now I just need some sun to capture a few comparison images. Though It doesn't look any better on the monitor!

Early efforts were rewarded more than I deserve. I was saved by ImPPG. Then the cloud arrived! It's going to be one of those days! I am trialing my T-S binoviewer GPCs on the ASI174 1.25" camera adapter. 1.6x and 2.6x. Quite pleased with the variation in scale compared with my usual 2x WO Barlow. They offer useful variations in power depending on the seeing conditions.

Well done Den! That is a real piece of Solar art!

Thanks Mark. I just wish they were better. The seeing soon went off once the sun escaped the overcast. Perhaps I need a fan to draw air through the tube? Worth a try given how little work is involved. A suitable hole saw and Bob's your uncle.

Thanks Dave. Well worth a go right now if you can avoid poor seeing, cloud and chores. Proms as well as blobs.

Overcast until after 11.00. Seeing soon went south after that! Still a bit of cloud about. I'll keep trying. As you do.

You can't be too critical to have such a superb image of a globular cluster. As in: Spikes? What spikes? EDIT: Any shiny bits in the focuser drawtube or camera adapter tube?

Sorry to hear about this. These barstewards are anything but dome-esticated! GRP repairs are easy. External cosmetics sometimes less so. Tons of advice available but let's see what damage has been done first. Then we can move on from there. What about insurance? Any hope there?

For nearly two decades I was limited to an average of 120x on my 150/8 Celestron refractor. I couldn't ever see any detail in Jupiter's belts though Saturn was much better and Mars less so. The scope lived in an unheated shed so cooling wasn't a factor. Saturn was "orbiting spaceship" razor sharp, when high on one particular, cold night with an inversion layer and snow on the ground. Though Jupiter remained frustratingly fuzzy and "boring" on the same night. Which of them proved the telescope could be razor sharp? Swapping to a 180/12 iStar and putting it in a second floor wooden observatory literally doubled my average viewing power overnight. Telescope or seeing? I think I just lifted myself off the ground where the awful seeing was concentrated around my pier. Even when I kept moving it to different bits of the garden to see between the trees and high hedges. Those who suffer consistently from awful seeing might do worse than building a simple, raised wooden platform or raised ROR. Domes have their own problems depending on materials and colour. My supposedly poor 150/8 performed very well on the sun in H-alpha at high magnifications. Yet I was never very aware of its f/8 chromatic handicap. The Fringe Killer was always optional. The iStar 6" f/10 H-a which finally replaced it can capture Plato craterlets and did very well on a crescent Venus at first try. My 10" f/8 premium mirror [even badly collimated] Newt trashed them all. Even down on the ground. I read somewhere, probably 50 years ago, that the average UK seeing is in 10" deep layers. Which is why it affects larger apertures because the seeing varies across the aperture. So the optical precision of the larger optic is lowered in comparison with a smaller one. There are no fixed rules. Only local conditions, instruments and observers. Being rural detached and surrounded in fields is no guarantee of good seeing. Ask me how I know?

I find myself in some agreement with your arguments but not all of them. I swap back and forth frequently between my original PST BF and a Lunt B1200S2 BF. There seems to be no obvious logic to the correct choice. I just use the one which suits the conditions and subject matter at any particular moment. It takes only a few seconds to swap between them as I have the PST BF in a home turned sleeve in a 2" fitting. The B1200 sometimes offers startlingly better contrast than the PST BF on surface detail. At other times it is completely fogged out by ZWO ASI174MM camera noise due to excess Gain. The PST BF passes far more light than the Lunt 12mm BF. So I [usually] use the PST BF for proms. The Lunt is simply far too greedy for Gain and noise intrudes. At other times I cannot reduce the light throughput enough using the PST BF. Because I am down to 0 Gain and less than 1ms exposure in SharpCap. Typically I use 800x600 frame size = 400fps regardless of the WO 2x Barlow/GPC nosepiece being on the camera. Peter, very sensibly, does not image. His visual rig is the envy of all who have tried it. His vast experience at optics and instrument building puts most other humans to shame.

At 8 o'clock and 10 o'clock there are disturbances near the eastern limb with pale patches.

Good write-up! The Head Gardener suggested you hang the "Vegiebogie" under the tripod to get it off the ground. It might help to damp [off] the vibrations.

$600? 😱

I have an old 90M f/11 OTA presently "resting." [On its nose.] I wondered about the container behind the telescope in the image: Doing an oil change?

Sorry. I meant to get back to you on this but wanted to confirm first whether the new ZWO driver download had helped my cause. The trouble is I'm fighting cloud. Which doesn't offer any opportunity to capture anything at all! I'm on full gain and peering through the clouds!

I have always been a martyr to telescope envy. Fullerscopes was offering virtual reality long before the <cough> "real thing" came along. They should have sold raffle ticket to "wishful thinkers."

Thanks Mark. Here are two more later shots: Completely clouded over now.

If you have the H-a gear then get it in gear.

The sun always shines on SolarChat!

Thanks Freddie. Swapping cables had no effect. Not even thought about drivers. Until now. I'll be back.

Thanks again Freddie. I was imagining having to do a dark and a flat for every single capture. Rod operated, flip-top, hinged objective lids, with a dark cap and a flat screen were being examined as the next project. I believe Alexandra has mentioned having very similar noise problems with her own ZWO ASI174. She reports that other manufacturer's versions, using the same chip, do not exhibit such noise. Basler, et al. My ZWO ASI174MM has developed noise and a coarse grain over time. It now shows up on lunar captures as well in very cool conditions. Making it worthless for that purpose. When I first used it on the Moon it could capture Plato craterlets. Not any more! One dealer wants me to send him examples of my affected images on the ZWO ASI120MC. These will be forwarded to ZWO and then a return address provided once the fault has been diagnosed. This sounds very time consuming! The ASI174 came from a well known, UK dealer. I have not contacted them yet. I was hoping to find a workable solution here first. To avoid losing what fills all my days and months in isolation. With two ZWOs cameras now all but useless I should be looking for a far more productive [and far cheaper] hobby! I have huge amounts of time and effort invested in building my observatory and its equipment. Not to mention the considerable expense. Fortunately it was hugely rewarding. Until now.

Interesting response. Thanks. Can you explain these "errors" please? You are obviously doing something right to have obtained these very even images. I have only just begun to use flats for my own PST etalon based 150mm/10 H-a imaging. I swap regularly between a BF5 and a LUNT 12mm BF. Choosing the one which works best on the subject. Though I use SharpCap, AS!3, ImPPG and PF7m, I have found flats rather "high maintenance" but beneficial. Your own telescope build and processing experience might hold valuable information for us all. Thanks again