I'm having greater and greater success with my PST 100 mm. So now I'm looking at my 152mm F6.5 achromat.
What are the mechanics to use f6.5 rather than f10? I'll stay with the Stage One Mod still.
Thanks,
Jack
Using an f6.5 152 Refractor for Stage One Mod
-
- Almost There...
- Posts: 783
- Joined: Tue Feb 03, 2015 3:44 pm
- Location: Vista, CA
- Has thanked: 141 times
- Been thanked: 240 times
- Contact:
Using an f6.5 152 Refractor for Stage One Mod
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
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
- marktownley
- Librarian
- Posts: 42272
- Joined: Tue Oct 18, 2011 5:27 pm
- Location: Brierley Hills, UK
- Has thanked: 20435 times
- Been thanked: 10243 times
- Contact:
Re: Using an f6.5 152 Refractor for Stage One Mod
You need to look at replacing the collimating lens. Also you need to consider the ERF, 152mm generates some energy that must be dealt with.
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!
- Merlin66
- Librarian
- Posts: 3970
- Joined: Tue Dec 13, 2011 1:23 pm
- Location: Junortoun, Australia
- Has thanked: 173 times
- Been thanked: 615 times
- Contact:
Re: Using an f6.5 152 Refractor for Stage One Mod
If you don't change the front collimating lens to match the scope, the etalon will act as an f10 aperture stop and you'll end up with a 99mm f10 system....no improvement there....
"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
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
-
- 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: Using an f6.5 152 Refractor for Stage One Mod
Thanks to you both.
What about adding a 3rd lens to correct to F10?
And which lens is the collimating lens in a doublet?
Lastly, my ERF is 100mm so I am hoping there is not too much heat that far up in the optical path.
Thanks,
Jack
What about adding a 3rd lens to correct to F10?
And which lens is the collimating lens in a doublet?
Lastly, my ERF is 100mm so I am hoping there is not too much heat that far up in the optical path.
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
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
- Merlin66
- Librarian
- Posts: 3970
- Joined: Tue Dec 13, 2011 1:23 pm
- Location: Junortoun, Australia
- Has thanked: 173 times
- Been thanked: 615 times
- Contact:
Re: Using an f6.5 152 Refractor for Stage One Mod
Jack,
It is possible to use a Telecentric type barlow to give the amplification, but it's not easy to set-up.
I'm not sure I understand your comment re "collimating lens in doublet".....
The PST etalon assembly has a single element -200mm focal length lens at the front, then the etalon and a +200mm focal length lens at the rear to re-image.
Some modders have replaced the front negative lens with one to better suit the donor fratio.
For a f6.5 system you'd be looking for a 25mm diameter x -163mm lens.
It is possible to use a Telecentric type barlow to give the amplification, but it's not easy to set-up.
I'm not sure I understand your comment re "collimating lens in doublet".....
The PST etalon assembly has a single element -200mm focal length lens at the front, then the etalon and a +200mm focal length lens at the rear to re-image.
Some modders have replaced the front negative lens with one to better suit the donor fratio.
For a f6.5 system you'd be looking for a 25mm diameter x -163mm lens.
"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
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
- Merlin66
- Librarian
- Posts: 3970
- Joined: Tue Dec 13, 2011 1:23 pm
- Location: Junortoun, Australia
- Has thanked: 173 times
- Been thanked: 615 times
- Contact:
Re: Using an f6.5 152 Refractor for Stage One Mod
Good point!
For an open aperture of 20mm then the focal length would be 130mm.
For an open aperture of 20mm then the focal length would be 130mm.
"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
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer