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Mon 14th 35F, full sunshine with strong NW winds. Seeing is not very good at first. With some limb boiling. Blank disk in white light. Altitude only 12°. 180mm f/12 R35 + green Solar Continuum.
A small prom. at my 10 o'clock in binoviewer 20mm Meade 4000 EPs. Just confirmed in Gong Cerro T. [only] at 4 'clock on the limb. 150/8 [120/10.]
My new PST filter barrel adapter is giving me a more centered darker [etalon?] ring. Measurement from the rear of the etalon ring shows it is still long at 210mm. This can be adjusted out at the AOK fitting. Cleaned the PST etalon, ITF and BF5 with a lens tissue and bulb puffer.
Steadily improving seeing at 12.00 with finer adjustments to focus and etalon tuning rewarding with more even spread of surface detail and finer detail at the limb. I'm seeing a small hump on the limb at my 12 o'clock [inverted.] 6 o'clock true.
It is strange how the entire surface pops into view as my eyes settle in the binoviewer. I believe there is also the seeing involved. The better the seeing [with increased solar altitude] the more even the spread of fine surface detail. Tiny dark spots show up where I could see nothing at first. Just practice I suppose. Like planetary viewing. Still some limb boiling but much less than earlier. 12.27 CET and surface detail increasing. Even small dark threads [filaments] becoming visible.
12.50 Proms at my 1-2 o'clock. 7-8 o'clock true. A dim arch and a bright 'mast.' No confirmation on Gong yet. Proms now appearing at 6-7 o'clock Inv. Fast moving cloud increasing from NW. Cerro T. is now showing the proms.
13.11 Small dark spots around my 2-3. Wind increasing with more cloud. 13.30 indoors for lunch to warm up! I really should wear my warmer boots. The rest of me is fine after I put on some gloves.
There is still the matter of the 90mm D-ERF alignment. It hasn't [been] changed since I first installed it some 13 months ago. Back then I was using a dowel through the focuser to tilt the filter and its supporting baffle! So it is a large unknown regarding its effect on the clarity of my view. If I was to make an adjustable cell it would be best to wait for a dull day rather than wasting valuable sunshine. I'd need an access door. Which should be positioned to avoid baffles.
I dismantled the 6" f/8 Celestron to remind myself what I had done with the Baader D-ERF and the baffles. The original optical layout no longer made much sense since the PST components stopped down the telescope to 120mm f/10. This meant that the light cone from the objective was narrower but of the same length.
I drew a full sized optical layout of the bare 150 f/8 and the 120 f/10 overlapping each other. The PST's etalon is 20mm in diameter and normally fixed at 200mm inside focus. So I drew lines from a 120mm aperture to the etalon. On that new taper I could move the baffles and D-ERF towards and away from the objective and focus to more optimum positions.
Where before they might have obscured the light cone they now cleared it more easily. The D-ERF could be moved nearer the objective [if desired] without vignetting the narrower light cone. The nearer the objective I placed the D-ERF the further the burning cone of reflected and refocused light would project beyond the dewshield. Moving it towards the focuser can hardly be described as wasting its 90mm aperture. It is what it is and has already been paid for. At that point I decided to think about the layout overnight. It kept raining so I had to close the shutters. It is much more fun sitting in the opened dome with the sun shining.
Wed. 16th. Since it was completely arbitrary where the D-ERF should sit, I put it in the middle of the tube as it was and aligned reflection of my eye with the center of the tube. Then I rebuilt the H-alpha OTA and remounted it in the rings.
I have moved the digital thermometer onto the pier above the laptop and run the external sensor wire to place the sensor outside in deep shade under the veranda floor. I bored a small hole for the sensor in the pier so there were no trailing wires inside the observatory. I like to monitor inside and outside temperatures to compare with the "seeing." I may tidy away the AWR drive cables to put them inside the pier. Though it will need larger holes for the plugs to pass through.
I still need to fit a sun screen to the tops of the OTAs to avoid being blinded by sunlight when looking through the telescopes. Since both telescopes will be pointing directly at the sun only a small shade is needed. I'll use card mounted on a bit of alu.angle profile on the upper tube ring[s]. A sun screen has been a need for ages without my ever making a start. Another roundtoit which should ideally be done in today's wind and rain.
With an endless supply of free card I can experiment to see what works best. Checking with the real sun I found that I probably needed a crescent shaped card to wrap around both OTAs.
Have I mentioned that I use the 8x50 finder to project a solar image onto the inside of the dome. The bright circle is placed inside its own round shadow to find the sun quickly. The finder is far too high to tempt me to take a peek though it. I'd need a stepladder! This saves lots of messing about opening a planetarium software. Or for when I don't have the laptop in the obs. I have a proper bag for the laptop now and can take the laptop back indoors when I'm not in the obs.
Steadily improving seeing at 12.00 with finer adjustments to focus and etalon tuning rewarding with more even spread of surface detail and finer detail at the limb. I'm seeing a small hump on the limb at my 12 o'clock [inverted.] 6 o'clock true.
It is strange how the entire surface pops into view as my eyes settle in the binoviewer. I believe there is also the seeing involved. The better the seeing [with increased solar altitude] the more even the spread of fine surface detail. Tiny dark spots show up where I could see nothing at first. Just practice I suppose. Like planetary viewing. Still some limb boiling but much less than earlier. 12.27 CET and surface detail increasing. Even small dark threads [filaments] becoming visible.
13.11 Small dark spots around my 2-3. Wind increasing with more cloud. 13.30 indoors for lunch to warm up! I really should wear my warmer boots. The rest of me is fine after I put on some gloves.
There is still the matter of the 90mm D-ERF alignment. It hasn't [been] changed since I first installed it some 13 months ago. Back then I was using a dowel through the focuser to tilt the filter and its supporting baffle! So it is a large unknown regarding its effect on the clarity of my view. If I was to make an adjustable cell it would be best to wait for a dull day rather than wasting valuable sunshine. I'd need an access door. Which should be positioned to avoid baffles.
I dismantled the 6" f/8 Celestron to remind myself what I had done with the Baader D-ERF and the baffles. The original optical layout no longer made much sense since the PST components stopped down the telescope to 120mm f/10. This meant that the light cone from the objective was narrower but of the same length.
I drew a full sized optical layout of the bare 150 f/8 and the 120 f/10 overlapping each other. The PST's etalon is 20mm in diameter and normally fixed at 200mm inside focus. So I drew lines from a 120mm aperture to the etalon. On that new taper I could move the baffles and D-ERF towards and away from the objective and focus to more optimum positions.
Where before they might have obscured the light cone they now cleared it more easily. The D-ERF could be moved nearer the objective [if desired] without vignetting the narrower light cone. The nearer the objective I placed the D-ERF the further the burning cone of reflected and refocused light would project beyond the dewshield. Moving it towards the focuser can hardly be described as wasting its 90mm aperture. It is what it is and has already been paid for. At that point I decided to think about the layout overnight. It kept raining so I had to close the shutters. It is much more fun sitting in the opened dome with the sun shining.
Wed. 16th. Since it was completely arbitrary where the D-ERF should sit, I put it in the middle of the tube as it was and aligned reflection of my eye with the center of the tube. Then I rebuilt the H-alpha OTA and remounted it in the rings.
I have moved the digital thermometer onto the pier above the laptop and run the external sensor wire to place the sensor outside in deep shade under the veranda floor. I bored a small hole for the sensor in the pier so there were no trailing wires inside the observatory. I like to monitor inside and outside temperatures to compare with the "seeing." I may tidy away the AWR drive cables to put them inside the pier. Though it will need larger holes for the plugs to pass through.
I still need to fit a sun screen to the tops of the OTAs to avoid being blinded by sunlight when looking through the telescopes. Since both telescopes will be pointing directly at the sun only a small shade is needed. I'll use card mounted on a bit of alu.angle profile on the upper tube ring[s]. A sun screen has been a need for ages without my ever making a start. Another roundtoit which should ideally be done in today's wind and rain.
With an endless supply of free card I can experiment to see what works best. Checking with the real sun I found that I probably needed a crescent shaped card to wrap around both OTAs.
Have I mentioned that I use the 8x50 finder to project a solar image onto the inside of the dome. The bright circle is placed inside its own round shadow to find the sun quickly. The finder is far too high to tempt me to take a peek though it. I'd need a stepladder! This saves lots of messing about opening a planetarium software. Or for when I don't have the laptop in the obs. I have a proper bag for the laptop now and can take the laptop back indoors when I'm not in the obs.
Click on any image for an enlargement.
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