I don't want to hijack the present threads on motor driven, etalon tuning any more than I already have. Th builder's deserve the admiration of those of us who value their contribution to "hands-off" or remote imaging. My task is to drive the standard PST etalon adjustment band reliably using a Skywa...

Congratulations on your neat execution. Being able to adjust these things without physically touching the telescope is a real boon. Probably one which is grossly underestimated by those who have never enjoyed such "remote control." With this facility, it often comes as a complete shock to discover h...

The mechanical advantage [ratio between the difference in diameters] should help.
If not, a larger radius is easily achievable by mounting a suitable ring on the PST Etalon band.
I'll be back!

Well done but, if you will forgive me for saying so, unnecessarily over-complicated. ;) This little motor happily drives my 3.5 FT focuser while vertical on my 180mm. It does so even with the hefty Lacerta 2" prism and ZWO camera attached. The toothed drive belt slips remarkably smoothly on the FT's...

Your fine images nicely illustrate the sheer scale of the sun's surface texture compared with "tiny" Mercury.
From a similar viewpoint, the Earth would be just as utterly insignificant as [say] Venus in transit.

Let's try to improve your chances of seeing something different. Other than a plain, blank, red disk: There's not much happening on the disk at the moment but that doesn't mean there is nothing at all to see: First step: Check Gong Ha [http://halpha.nso.edu/] website for clues as to where the main p...

Thanks. I'd better cancel that order. ;-)

I there was a specific solar filter foil, with slightly lower reflectivity than standard , we could routinely use much larger apertures for H-alpha at low cost . Our common reflectors could be used without the astronomical cost of full aperture D-ERFs. No need to strip our existing mirrors. With mos...

Thank you for your useful responses.

So the advantage of the higher quality of the APO lies mostly in its improved, spherical figure and more careful polish? Rather than its ability to bring more colours to the same focus.Which may not even include H-alpha in their prescription. It follows that a single, aspherical lens could replace t...

Hi Pedro,

I greatly admire your images.

Some people say you don't need a high quality APO for solar H-alpha imaging because H-a is monochrome.

Even the camera is usually monochrome. So there is no chromatic aberration to spoil the image.

Would you agree?

Thanks

Apologies if your ZWO tilt plate adapter has socket head screws [like Pedro's top image]
Rather than the big thumbscrews shown in my image above.
I ordered ZWO but may have received a clone.

If this is the case then the system is identical but the screws just look different to mine.

I have the ZWO tilt adaptor and my brain physically cannot work out how to move it in any way. It always move the opposite way to what I want or is too tight to move, then you loosen it and you are back to square one. I have no idea in the slightest how to use it, I just don't understand the mechan...

Superb animation!

The animations and images on your website are also amazing!

The fire brigade has just left. <choke-cough> I'd left a cardboard stop ring in the dewshield of the 6". I had completely forgotten about it from Friday's battle with the clouds. The reflected return beam from the D-ERF had set it alight and acrid smoke had filled the observatory! Anyway, I fitted t...

Thanks Bart.

Sunny periods promised tomorrow.

I'll report back when I have compared the GPC x 160mm to the 120mm stop x 200mm.

bart1805 wrote: ↑

Sat Oct 26, 2019 11:25 am

If it it satisfies me is not so important, if it works is the question. Yes, this is perfect.
now find the minus 160mm spot and place the GP there. Good luck!

Thanks Bart.

How did we arrive at 160mm?

The cheapest tilt plates with thumbscrews are awful IMO.
The push & pull thumbscrews are far too close together to allow easy adjustment.
I intended to fit mine with hex socket head screws so I can adjust the tilt with a long series hex key or hex driver.

I hope the new GPC position satisfies Bart. First the AOK 2" nosepiece was bored to 28mm Ø in the lathe. This allowed the 'nose' of the GPC to pass through. The etalon now holds the GPC gently up against the inside of the AOK baffle using rubber washers for packing. Moving the washers under the GPC ...

Hi Whats the design back focal position of the Baader 1.25x Glasspath to give that magnification? Rod tested 2x Barlows at -200mm and they actually gave 4x. Have you measured the image size without and with the Glasspath? Andrew. Not yet. Heavy cloud for most of the afternoon made any real measurem...

Rusted, I don't understand what you are building. It is far more simple. Place the Glasspath really close to the front lens of the etalon. In a f/10 telescope you would place the front lens of the etalon 200mm before the focus point. In a f/8 with a 1.25x Glasspath you place it 160 mm before the or...

Meanwhile, back at the ranch: I tried the Baader 1:1.25 GPC in my 6" f/8 today. The focus was shifted 18cm away from its original position. I made no effort to move the etalon to match. But built instead a ridiculous and flexible length of multiple 2" Ø adapters to allow my ZWO 120MC to come to focu...

Hi Merlin, I had a good look but cant find it. Transmissions from memory were in the range 60-40%. Andrew Is it possible you are mistaken in thinking this was mentioned on CN? I am struggling to imagine any scenario where CN would tolerate such discussion. I was barred from the CN forum for daring ...

Hi Are you using a 2" red filter as an internal ERF? My friend used one and forgot to check after adding a Barlow and cracked a red filter. Still useable though as not at focus and seemed to have clear cover glass holding it together. There are various Solar discussions on CN. A review of front DER...

But did you read the processing tutorial that goes with IMPPG? Solar imaging is the same as every form of astrophotography. The processing part is equally important as the actual gathering of raw images, some say it is more important. There is no absolute strategy, but with the pointers Alexandra g...