PST Mods... but, why not a 40mm SolarMax Mod?

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PST Mods... but, why not a 40mm SolarMax Mod?

Post by MalVeauX » Sun Oct 07, 2018 6:33 pm

Hey all,

I'm curious, probably late to this party, but there are tons of PST mods out there, but I don't see as much attention to the 40mm Solarmax double stacking unit, for the same purpose? These often are sold as cheap, used, as the PST is. I imagine it has a larger internal diameter and you don't need a blocking filter and all that extra stuff you toss out with a PST anyways, adapting it to use with your own much larger DERF and your own much larger blocking filter. So I'm curious... what am I missing? I don't have one to disassemble to answer that myself. But I'm curious if you take the ERF off the front of a Solarmax 40mm double stacking unit, you have a tunable etalon with threads on both sides, minus all the PST stuff, and a larger diameter to work with I think?

Anyone have any links that they've saved over the years regarding using a solarmax 40 doublestack unit (same thing used to doublestack a PST) with donor scopes like big refractors or a SCT?

Very best,

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by Carbon60 » Sun Oct 07, 2018 7:24 pm

Hi Marty,

I guess it would be done in the same way, or similar way, as my Lunt35 mod.
viewtopic.php?f=9&t=11271&p=112624&hili ... od#p111990

An internal Barlow lens within the donor scope feeds the front mounted etalon.

Stu.
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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by marktownley » Sun Oct 07, 2018 7:47 pm

You're forgetting the central spacer Marty on the etalon. It's like a dust bunnie the size of Greenland... Lunt 35 has no central spacer though ;)
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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by MalVeauX » Sun Oct 07, 2018 8:30 pm

Hrm,

I didn't notice the central spacer thing in the Solarmax. I'll have to look more into that stuff. It makes sense from that perspective why folk are using the Lunt 35 & PST HA etalons without a central spacer. Weird that there's a spacer like that, basically an obstruction, defeating the point of a refractor. Odd.

I'm still curious though. It's not like Lunt 35's are just laying around and as inexpensive as PST's these days. I see a Lunt 35 now and then, for cheap, but they're much more rare than a PST.

Worse case, there's always used 50mm Lunts too, at twice the price. I rarely see anyone using these either.

Very best,

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by marktownley » Sun Oct 07, 2018 8:57 pm

There's a whole bigger story behind the central spacer - your next step would be to start reading the patents on the solarmax etalons.

Strange how those 35s and 50s aren't for sale on the second hand market as much ;)
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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by MalVeauX » Sun Oct 07, 2018 11:24 pm

While the solar market is small as it is, the modding solar market is even smaller. I've not attributed the lack of a particular item on the used market to be a sign of anything statistically significant with respect to modding. I would hazard a guess that there's less people modding 60mm, 80mm, or larger stock HA scopes for the purpose of going higher resolution as the scopes cost so much people are less likely to even think of opening them up. The PST on the other hand costs as much as a fancy night out, so people are more likely to risk them.

That said, I really do regret not getting a Lunt 50mm when they were on sale, new, from B&H for $499. Sigh!

Very best,

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by TheSkyBurner » Sun Oct 07, 2018 11:33 pm

marty: you have a very powerful tilt adapter than can do hydrogen alpha for like $500..... its called skybender :) I could build it up for you but where is the fun in that. There is also dispersion prisms you can use, and diffraction gratings with slits.

You have a great quark. You can just get a better system by attaching a slit and splitting the spectrum further.

A skybender with a 5 angstrom h-alpha filter from andover. then a diffraction grating, you will have the .1angstrom h-alpha setup. Do you want full disk? Do you want high mag? Cant have both with a slit.... Gotta think outside of the box! Remember, this stuff has been done in the early 1900's.

If my theory is correct, this stuff has also been done 2000 years ago by the various civilizations like the greeks romans and egyptians and arabians. Those guys were experts at polishing glass, so to conclude telescopes were not in use is just modern nonsense. Any crystal = an optical lens. They had jewels up the wazoo, and golden mirrors. They had gears, and clocks, they had archimedes. They had pythagoras, they had thoth, and even merlin. These guys had solar telescopes and were watching sunspots for sure, it was just a closely guarded secret.

ls35 in telecentric.jpg
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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by MalVeauX » Sun Oct 07, 2018 11:53 pm

Looking for potential candidates to take something like a C8 up to a high resolution system on a budget. No free lunch, of course, but at least we can explore options for HA etalons. I have my Quark. I have a PST etalon. But I'm always curious about other options. I have full disc covered, but full disc during a minimum is not really interesting, other than to show how minimum the minimum is. High resolution shows tiny details during the minimum and is of course nuts during the maximum. So I'm exploring potential options. Lots of folk seem to harvest the PST and use Quarks, as they are budget options to go higher resolution. I'm just also looking at other etalon options. I have HA covered in general. I'm just looking to what could be done with a larger aperture (200mm as a starting point) with budget interference etalon filter options.

Very best,

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by TheSkyBurner » Mon Oct 08, 2018 1:20 am

MalVeauX wrote:
Sun Oct 07, 2018 11:53 pm
Looking for potential candidates to take something like a C8 up to a high resolution system on a budget. No free lunch, of course, but at least we can explore options for HA etalons. I have my Quark. I have a PST etalon. But I'm always curious about other options. I have full disc covered, but full disc during a minimum is not really interesting, other than to show how minimum the minimum is. High resolution shows tiny details during the minimum and is of course nuts during the maximum. So I'm exploring potential options. Lots of folk seem to harvest the PST and use Quarks, as they are budget options to go higher resolution. I'm just also looking at other etalon options. I have HA covered in general. I'm just looking to what could be done with a larger aperture (200mm as a starting point) with budget interference etalon filter options.

Very best,
well you can use 8" sct if it is f10 with your pst, and you can definitly use it with your quark. All you need is a full size erf.

Thats where the budget turns into an aligator, id say start saving and get the baader planetarium D-erf filter. but unfortunatley you lose 25mm on your aperture. Valery is the only person selling them for 8" scopes.

Id buy one with you, there is a minimum 2-pc order on parts at schott glass for the custom d-erf specification. It wont be cheap, but it would certainly be 30% less and not have to be shipped over an ocean. The best way to make these purchases is with a planned group event buy. Multiple purchases for one order invoice = 25% or more discount. But then you gotta figure out how to mount it...

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by Valery » Wed Oct 10, 2018 2:18 pm

Marty,

If you want to get the most out the equipment you got and get the most cost effective high res solar telescope, then
better use tested solutions which showed that they really work as needed. Forget all these SM35, SM40 etc.

a) Full size DERF + C8 + standard Quark Chromosphere + Camera (depends of camera pixel size use or not a focal reducer).
You already have a Quark.

b) Full size DERF + C8 + PST Mod2 (even PST blocker 5-6mm is OK when used properly) + Barlow 2x, 3x or 5x depends of camera pixel size.

c) Double stack with Quark + PST etalon without it's lenses.

d) For CaH: the same full size DERF + C8 + a lens (I will tell you which one) + CaH Quark.
Instead of Quark CaH you can use Lunt B1200 or B1800 -depends of camera chip size.

e) for G-band: the same full size DERF + balow + Andover 430nm filter


See the images taken with PST etalon configuration. Several of them are with C8 + 214mm ARIES DERF.
viewtopic.php?f=11&t=21666


Valery.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by MalVeauX » Wed Oct 10, 2018 4:45 pm

Thanks Valery,

Very interesting. A PST etalon & Quark together serves as a double stack and has a blocking filter without having to get anything other than the mounting hardware. I'm curious how it performs, if folk are doing that, and what kind of transmission it has? That would be quite interesting for a no-free-lunch approach to a budget double stack high res system. Quite curious!

Very best,

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by Valery » Wed Oct 10, 2018 8:24 pm

MalVeauX wrote:
Wed Oct 10, 2018 4:45 pm
Thanks Valery,

Very interesting. A PST etalon & Quark together serves as a double stack and has a blocking filter without having to get anything other than the mounting hardware. I'm curious how it performs, if folk are doing that, and what kind of transmission it has? That would be quite interesting for a no-free-lunch approach to a budget double stack high res system. Quite curious!

Very best,
This image is what you are looking for. download/file.php?id=34232

It was taken with the very same ARIES DERF (just larger in size) and C11 telescope. Quark + naked PST etalon.
Camera Basler 1920-155 with IMX174 chip. No even faintest trace of double limb. No photosphreric noise, just a
core of H-a line.

Here you can see what can be images with the same DERF at 393nm. My best images are even better.
viewtopic.php?f=4&t=25129

So, all you need is forget about all these experiments and buy an ARIES DERF 214mm.


Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by MalVeauX » Wed Oct 10, 2018 8:28 pm

May I ask what exposure time & gain you had to use with that configuration? I'm curious how transmission is. Looks like it's good!

Then again, not just any old PST etalon will do the trick I imagine, probably need quite a good one?

Thanks for the examples, that's exactly the kind of simple system I'd like to build eventually.

Very best,

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Re: PST Mods... but, why not a 40mm SolarMax Mod?

Post by TheSkyBurner » Wed Oct 10, 2018 11:57 pm

Valery always makes great images, but i personally think his processing is too dark.

Valery i hope you do not mind i boosted some levels..

Marty: i also agree with valery, you should just buy his D-erf, there is no other way around it since you are dead set on SCT. I would buy one right now if i didnt hate SCT telescopes so much.

I would however stay away from the 8" one because i already know you are gonna want the C11, look how fast you went from 80mm to 120mm then to 150mm.. Going from 150 to 200 is not a huge gain in aperture fever, although the price is more attractive..

However going from 150 to 280mm is a massive increase. You will just kick yourself in the butt for not doing the bigger one in a couple months. (more is never enough until its overwhelming ) Dump your 120, dump your 150. dump your c8. This is an investment in yourself, and in the long run is like a car. You will be using this thing for many many light years.

It sounds crazy expensive but you can still use the 11" filter on your c8, just need a downsizing collar and with a size like that its going to retain its value for many years even during solar minimum

Perhaps these numbers will help you decide where you want to be?
Aperture 150mm (6")
Focal length 1500mm (59") <------- starting From Here
focal ratio F/10

Aperture 203.3mm (8") <---53mm gain 35% gain. <-----un-appreciable gain
Focal length 2032 mm focal length (80")
Focal ratio f/10

Aperture 279.4mm (11") <---129mm gain 86% gain <---- massive visually apparant gain.
Focal Length 2800mm (110") <-------to here. Nearly double right out of the box.
Focal Ratio f/10
https://www.celestron.com/products/c11- ... e-assembly Sct's are super cheap on ebay right now.
https://www.ebay.com/itm/Meade-LX200-EM ... 2830819413
2017-Aug-05-UT06h25m-C11-ARIES-DERF-Ha-DS-Basler-1920-155.jpg
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