Is a Lunt ERF all that is needed for a Stage 1 PST Mod

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...
Post Reply
Starry Jack
Almost There...
Almost There...
Posts: 783
Joined: Tue Feb 03, 2015 3:44 pm
Location: Vista, CA
Has thanked: 141 times
Been thanked: 240 times
Contact:

Is a Lunt ERF all that is needed for a Stage 1 PST Mod

Post by Starry Jack »

I had fun with my creative side, and I thank all the patient comments, but now I just want the project done correctly.

If I get the Lunt 75mm ERF for my 100mm Stage 1 PST mod, is that the only filtration I need? Will that provide all the PROTECTION I need?

I understand that the Baader is the superior ERF, but it carries a pretty high price. I also know the Baader is 1/10th wave, but when I called Lunt they said they were "at least 1/8th wave."

If I get the Lunt for my first foray into PST Mods, will that enable the Stage 1 Mod to finish? Then later when funds are different, I can get the nicer Baader, and perhaps one that will even go over the objective.

Other than the ERF, my scope is ready; it has been shortened and the PST mounted.

Thanks,
Jack


Explore Scientific 152mm f6.5 achromat
Aeries D-ERF
Quark Chromosphere f27 native, (f14 when focal reduced)
Mallincam .5x focal reducer (large format)
12nm Filter
ZWO174 (IMX249 chip 5um)
Huge Sense of Adventure Viewing Creation
User avatar
Merlin66
Librarian
Librarian
Posts: 3970
Joined: Tue Dec 13, 2011 1:23 pm
Location: Junortoun, Australia
Has thanked: 173 times
Been thanked: 615 times
Contact:

Re: Is a Lunt ERF all that is needed for a Stage 1 PST Mod

Post by Merlin66 »

Yes is the basic answer....
You just need to mount the ERF internally at a suitable spacing with a slight tilt.
You could also mount the ERF externally (for trials ;-) ) and see the results from a 75mm aperture system. Just make sure the cell arrangement you use is light tight around the edges and securely attached to the front of the scope.


"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy  
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
Starry Jack
Almost There...
Almost There...
Posts: 783
Joined: Tue Feb 03, 2015 3:44 pm
Location: Vista, CA
Has thanked: 141 times
Been thanked: 240 times
Contact:

Re: Is a Lunt ERF all that is needed for a Stage 1 PST Mod

Post by Starry Jack »

LOVE IT!
How much tilt would you recommend? 1 degree? 3 degrees?

BTW...I did try the Baader 2" UV/IR Cut at about -400mm followed by a Baader 610nm 1.25" up near the etalon. I took temperature measurements by drilling a hole in the OTA and inserting a meat thermometer probe and touched the UV IR Cut filter front surface.

For historical (hysterical?) purposes, the temp went from about 81F air temp in the OTA to about 123F on the surface of the UV/IR Cut using the full sun disk at about high Noon.

Now that I had my fun...I want to try the tried and true... :-)

I'll get the Lunt filter ordered on Monday and let you all know the results.

Best,
Jack


Explore Scientific 152mm f6.5 achromat
Aeries D-ERF
Quark Chromosphere f27 native, (f14 when focal reduced)
Mallincam .5x focal reducer (large format)
12nm Filter
ZWO174 (IMX249 chip 5um)
Huge Sense of Adventure Viewing Creation
Starry Jack
Almost There...
Almost There...
Posts: 783
Joined: Tue Feb 03, 2015 3:44 pm
Location: Vista, CA
Has thanked: 141 times
Been thanked: 240 times
Contact:

Re: Is a Lunt ERF all that is needed for a Stage 1 PST Mod

Post by Starry Jack »

The results of my "creative" rig was that too much light of some flavor was hitting my Mallincam. Everything was too bright and I got no surface detail. I then added an old Japanese made Lumicon ND 25 on the nose of the Mallincam and I did begin to get surface detail.

Jack


Explore Scientific 152mm f6.5 achromat
Aeries D-ERF
Quark Chromosphere f27 native, (f14 when focal reduced)
Mallincam .5x focal reducer (large format)
12nm Filter
ZWO174 (IMX249 chip 5um)
Huge Sense of Adventure Viewing Creation
User avatar
swisswalter
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 17948
Joined: Thu Feb 06, 2014 4:28 am
Location: Switzerland
Been thanked: 1 time
Contact:

Re: Is a Lunt ERF all that is needed for a Stage 1 PST Mod

Post by swisswalter »

Hi Jack

good luck on the mod, You will do it. I would recommend a UV/IR filter on the nose of the camera next to a ND filter if needed


Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)
Starry Jack
Almost There...
Almost There...
Posts: 783
Joined: Tue Feb 03, 2015 3:44 pm
Location: Vista, CA
Has thanked: 141 times
Been thanked: 240 times
Contact:

Re: Is a Lunt ERF all that is needed for a Stage 1 PST Mod

Post by Starry Jack »

Yup! I do have a Baader UV IR cut on the nosepiece of the mallincam. I am eager to get the Lunt ERF.

suggestions always welcome and encouragement truly appreciated.
Jack


Explore Scientific 152mm f6.5 achromat
Aeries D-ERF
Quark Chromosphere f27 native, (f14 when focal reduced)
Mallincam .5x focal reducer (large format)
12nm Filter
ZWO174 (IMX249 chip 5um)
Huge Sense of Adventure Viewing Creation
Post Reply