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PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Wed May 08, 2019 12:02 pm
by solarchatted
ADDITION - I failed to mention I will use the Altair 178M camera I am already using with PST

Hi again!
Sorry for being 'slow' and possibly thick.

My plan:

1.
I think, first thing is to get the 2" adaptor for PST - so I am ready to play with Stage 1 [I guess it is called?]

2.
Then get a 100mm ERF [when i can afford it] and make an adaptor/cap myself - I am good at it [or so I believe!] and fit 3x Nylon screws on it to hold it in place, behind the edge for the retractor's shield.
Although I am now thinking I should take the shield off for Solar, so the ERF is next to the glass?

3.
Then fit the 100mm ERF over the AR152 [988mm FL - 152mm Diam - F/6.5] - so it becomes ~F/10

4.
Then eventually also test my AR102SX [459mm FL - F/4.5] and make a 45mm 'card-board' reducer covered in tin-foil 'over the 100mm ERF' and reach F/10 again

5.
For full disk I can use my SW 72ED and simply adapt the 100mm ERF cap over the SW 72ED - maybe just fit longer nylon screws to hold it!
I might have to keep those cream cheese card-board round boxes then (~110mm diam)!!!

6.
or simply get a 63/840 OTA and there is no need to get a ERF (although always best to get one!)

My questions:
a.
What are your 'expert' thoughts above my points above?

b.
Where am I going wrong in terms of 'being able to focus easily'?

c.
Please tell me I am thick, but give us a solution that can account for:
Results [first], Focusing and costs ?





I am no expert and cannot contribute much 'at least at this stage'

Thanks again for taking the trouble to reply.
M

PS I am a kind of practical guy and 'do this and do that' replies are the best to achieve ... at least with my brain ... I usually learn by watching others and as a friend of my late dad used to say: I might be no expert in something and it might take 5x the time an expert takes to do it, but I will blooming do it too! I take this approach too, but do a lot of research first and learn from others than know FAR more than me.
First you learn what I am going to do that, then the how to do that becomes easier knowing what you are doing.

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Wed May 08, 2019 12:07 pm
by solarchatted
Here a few images taken with PST + 178M.

https://astronomo.space/my-images/the-sun/

I t is so difficult to find good weather in Northern England to match my days off work!

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Wed May 08, 2019 12:35 pm
by solarchatted
This is another telescope I forgot to mention:
https://www.telescopehouse.com/telescop ... embly.html

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Wed May 08, 2019 8:11 pm
by marktownley
HIya, my thoughts...

1 - a necessity!
2 - Yes, for a more secure and easier fit for your ERF use masking tape and wrap around the perimeter of the ERF, make this so it is a push interference fit inside the dew shield.
3 - Yes
4 - Just use the PST native, you're not going to get much more going from 40mm to 45mm aperture to be perfectly honest.
5 - For full disk use the PST, with a 72mm scope your fov that is within the sweetspot is only going to be about a quarter of a disk.
6 - Why? if you have the other scopes already?
a - see above
b - Are you struggling with focus visually or with imaging?
c - cost wise the 90mm bresser is a winner, you could use a sub aperture ERF to conserve funds...

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sat May 18, 2019 4:11 pm
by solarchatted
Hi
Thank you very much for taking the time to reply.

It is almost as clear as daylight now and I am guessing I will not need to modify AR152 inward as I might use a smaller ERF [90-100mm] and reach focus?

Sorry for late reply as usual... I thought forum was set to auto-subscribe to get email notifications on my own thread.

OK, time for decisions now.

Thanks
M

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sat May 18, 2019 5:21 pm
by solarchatted
Oops!
I just thought about a 63mm or maybe a 80mm ERF used on a Meade SCT 10" Classic [old one].
Using it off-axis with PST ?

I did get decent images in white light years ago and I was only playing with it!

Maybe 63mm too small for a F/10 254mm 2500mm FL ?

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sun May 19, 2019 7:06 am
by marktownley
Personally, I would stick with your refractors for a PST mod. No point using the SCT unless it is full aperture with a full aperture ERF.

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sun May 19, 2019 10:44 am
by solarchatted
OK, understood.

Just slightly off-topic ...

This morning I 'thought' I had some SUN out and it was out then clouded up by the time I was ready to 'try' a Revelation or GSO 10:1 focuser in place of the original PST prism, using PTFE tape and fits well!

I had all OK, but the ITF with the whole PST original eyepiece holder held ... difficult to explain - unfortunately its thread is not same as standard diagonal or other similar bit and no x2 Barlow yet - I am doing visual.

I barely managed to glimpse The Sun and it seemed only slight out of focus.

It might make a better PST without the prism focuser!

Still cloudy, I have to got to my in-laws for Sunday Dinner soon.

Might try it later if it clears in the afternoon.

I cannot spend yet, so I am playing around a bit.

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Thu May 23, 2019 8:59 am
by solarchatted
I got it working!
Far better focusing + more light getting through.

I tried it yesterday with camera too, but although sky was clear, it was quite hazy - today might be clearer and I am at work!

My only problem remains the how to attach PST eyepiece holder onto 'whatever' can hold it as it is a non standard ... I think I measured it at 32mm 0.75 pitch.

Not spent any money ... yet!
;p]

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Thu May 23, 2019 5:05 pm
by marktownley
Nice mod!

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sat May 25, 2019 4:28 pm
by solarchatted
Thanks

... I did use 3 blocks of timber wrapped in Gaffa/Cloth tape on the ring over the PST tube to avoid scratches!

I will have to find time to play a bit more with it.

It is much brighter and I might end up using the 7nm Filter all the time - if not too narrow.

One thing I do not understand ... some time ago I did try the Altair 178c [colour] and it was better than the 178M using a standard RED filter and also 7nm filter and set Sharpcap Histogram onto the RED which was obviously huge thanks to the filters !
Strange, as the Mono is a much better camera.

I need to find the videos and compare.

I wish I was retired and FREE to take telescope out ANY time is possible and also get ki**ed by my wife!
;p]

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sat May 25, 2019 4:35 pm
by solarchatted
I forgot to ask something:

1.
The Bresser Messier AR-90/900 OTA Optical Tube Assembly https://www.telescopehouse.com/telescop ... embly.html, do I need to adjust tube length or not?

2.
Do I still have to take lenses off the PST Tuner if I use the above telescope?

Just trying to find a way to do it with minimal work, because I am not sure of anything and might 'waste' little money I have!

I have seen somewhere taking off the PST front glass and holder and push the whole tube in a telescope + the PST has the same mod I did above - with a SCT screw-on focuser!

If not - that is a HUGE plus and it probably is very light as well.

Thanks for your time - appreciated.

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sun May 26, 2019 3:50 pm
by solarchatted
Here is one of the images I managed to take with SCT focuser one and wobbly nosepiece holder - nothing special, also a lot hazy.
But surface I believe it is clearer!

I 'think' this was with a 2x Barlow (with also 2x Barlow lens end screwed onto camera) - not sure ...

https://astronomo.space/my-images/the-sun/
The Sun 22 May 2019 – 11:27UT PST (Single Stack) with SCT 10:1 Focuser test

Re: PST Stage 1 + AR152, AR102, 72ED etc. next steps ...

Posted: Sun May 26, 2019 3:59 pm
by solarchatted
I am now really tempted to get the Bresser Messier AR-90/900 OTA - I am not sure if I need to cut it or will work as is!