First light ready...just need the Sun

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Starry Jack
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Re: First light ready...just need the Sun

Post by Starry Jack » Wed Feb 25, 2015 5:08 pm

I just got a few minutes observing. Most slip was removed though I don't know if axial alignment is spot on. I found a huge amount of leopard spots in the FOV and discovered the objective had fine watermarks on it perhaps dew formed while in the observatory.

Again, the entire image is nice and bright but the sweet spot is very narrow. I could see a long north/south filament nicely but nothing to the east or west of it so you know the sweet spot was pretty narrow.

Are there other symptoms I should be observing to help diagnose?

Thanks,
Jack

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Re: First light ready...just need the Sun

Post by Starry Jack » Thu Feb 26, 2015 5:39 am

I cut the gold tube, and in so doing it unleashed the loctite so I could finally get the tube and etalon and black box all apart. I could not remove three of the screws (more loctite) from the prism box so I could only assess alignment of the prism by removing the etalon and BF.

I did not have any good way to measure, but it sure seemed to my eye it was a tad off, but that is only anectdotal and not based on measurements. I did turn the PST focuser all the way so that the prism was at the top of the box and while it seemed equal in space to the top of the box, it seemed to my eye a micro bit skewed to the front of the black box. But I could discern no way that would be possible so I left my assessment as, "not real valid".

I wrapped aluminum tape around several times around the shortened gold tube so that there was a very snug fit into the focuser. The only slop I can find now is a bit of slop in the focuser itself and I am not sure how to fix that quite yet...but I will. :-)

Lastly I cleaned up the ERF from the watermarks and I will give it another go tomorrow at lunch.

Thanks all,
Jack

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Re: First light ready...just need the Sun

Post by marktownley » Thu Feb 26, 2015 6:53 am

slop / sag in the focuser is normally the culprit...
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Re: First light ready...just need the Sun

Post by Starry Jack » Thu Feb 26, 2015 6:18 pm

BETTER! The sun was behind about a 50% cloud veil. The sweet spot was a much bigger field of you with the straightened out optics. But what made the most difference was using my 25 ND filter. So what I defined as a sweet spot, it seems to be over exposure, too much light.so now what I'm thinking is get a much lower grade neutral density filter and giving that a shot.

Jack

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Re: First light ready...just need the Sun

Post by Starry Jack » Sat Feb 28, 2015 2:09 am

Pictures at last!
I was able to grab 1-2 minutes at a time with the sun which was covered by a 75% thin cloud layer. At least I was able to record essentially what I have been seeing.

The good news is that the scope works and I have the most detail I have ever seen in the sweet spot of the PST. I am thrilled by that account.

You can see though that there is a darker arc which has the most resolution while areas outside the arc are over exposed. I will continue working on aligning the optical train, but do you have other thoughts about the performance (considering a ton of clouds over the entire FOV).
2015.02.27.114138.png
2015.02.27.131514.png

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Re: First light ready...just need the Sun

Post by swisswalter » Sat Feb 28, 2015 4:58 am

Hi Jack

not bad vor a Color CCD but I'm missing sharpness at least some where in the pic
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Re: First light ready...just need the Sun

Post by Starry Jack » Sat Feb 28, 2015 5:05 am

I never even had a chance to focus well since the clouds were moving so quickly. I only had about 30 seconds at a time.

Rain tomorrow.

Jack

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Re: First light ready...just need the Sun

Post by Valery » Sat Feb 28, 2015 8:08 am

You are on a right way, Jack.

Just make the etalon adjustment so, that the sweet spot (where the details are the most visible) not as the ring, but as the real spot which is the most
dark and contrasty in the it's center and somewhere around and farther starts to brighten and less contrasty.
Rotate the etalon forth and back and you will find such a position and you will find a right direction of the etalon rotation which
makes better tuning.

Also, such telecameras like MilliCam are not good for the imaging. You need a black and white industrial vision camera.
There are a plenty of them for a choice for any pocket depth.

You also can adjust the sweet spot visually - very easy to do. I did this with my PST etalon installed on 102mm and 150mm refractors
easily and then adjust only slightly when imaging.


Valery.
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