Hi everyone
I would like to do an observation test in H alpha with my “old style” Marcon SCT 250 mm. Unfortunately, as the Aries ERF filters were not available for the war in Ukraine at the moment, I contacted the supplier Airylab for an alternative; unfortunately, the company replied that they no longer produce ERF filters.
Since Baader produces ERFs with a maximum diameter of 180 mm, I don't know which alternative is available on the market.
Is anyone able to point me to an alternative solution for a 250 mm ERF ??
However, I take this opportunity to wish Valery to be able to resume production of the ERF as soon as possible .
Thanks
ERF for SCT 250 mm
- Arrakis97
- Ohhhhhh My!
- Posts: 179
- Joined: Mon Oct 11, 2021 8:35 am
- Location: Casalecchio di Reno (BO), Italia
- Has thanked: 350 times
- Been thanked: 306 times
- Contact:
ERF for SCT 250 mm
Carlo Casoli
https://www.flickr.com/photos/carlocasoli/
TEC140 Apo with Baader D-ERF 160 mm, Beloptik Telecentric 5x, Coronado PST, Solar Spectrum S.O. 0.5 A
LUNT Tha 80 D.S.
Tecnosky 80/480 Apo
Daystar Quark Cromosphere H alfa Filter
Lunt B600 Ca K filter
Baader Herschel Wedge
Ioptron CEM70-G & Tripier
https://www.flickr.com/photos/carlocasoli/
TEC140 Apo with Baader D-ERF 160 mm, Beloptik Telecentric 5x, Coronado PST, Solar Spectrum S.O. 0.5 A
LUNT Tha 80 D.S.
Tecnosky 80/480 Apo
Daystar Quark Cromosphere H alfa Filter
Lunt B600 Ca K filter
Baader Herschel Wedge
Ioptron CEM70-G & Tripier
- MalVeauX
- Way More Fun to Share It!!
- Posts: 1858
- Joined: Tue May 09, 2017 7:58 pm
- Location: Florida
- Has thanked: 1171 times
- Been thanked: 1360 times
Re: ERF for SCT 250 mm
You'd have to get it commercially made custom from someone, like Edmund Optics, etc, or any other lab but it will be enormously expensive for a single filter run that is custom (remember, the glass needs to be high quality and optically flat too, this adds to the cost). Baader does 180mm and Altair is doing some (and duo band ones) but nothing bigger either. And BelOptik only has smaller ones, when he's active.
I don't think there is anyone making a D-ERF in the 10~11 inch range at the moment, only Aries was. Hopefully Valery will be able to resume this after the war/politics clears up. We can only hope.
I have a 214mm Aries and it's in use every week to this day.
Very best,
I don't think there is anyone making a D-ERF in the 10~11 inch range at the moment, only Aries was. Hopefully Valery will be able to resume this after the war/politics clears up. We can only hope.
I have a 214mm Aries and it's in use every week to this day.
Very best,
- marktownley
- Librarian
- Posts: 42269
- Joined: Tue Oct 18, 2011 5:27 pm
- Location: Brierley Hills, UK
- Has thanked: 20424 times
- Been thanked: 10242 times
- Contact:
Re: ERF for SCT 250 mm
Your best chance is the second hand market short of a custom job which is ££££££££££££££££££££££££
Your other solution (assuming your seeing supports this aperture - have you checked this?) - ditch the idea of using the 250mm scope you are talking about and pick up a suitably large refractor and use a smaller (180mm/160mm) DERF sub aperture...
Your other solution (assuming your seeing supports this aperture - have you checked this?) - ditch the idea of using the 250mm scope you are talking about and pick up a suitably large refractor and use a smaller (180mm/160mm) DERF sub aperture...
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!
- MalVeauX
- Way More Fun to Share It!!
- Posts: 1858
- Joined: Tue May 09, 2017 7:58 pm
- Location: Florida
- Has thanked: 1171 times
- Been thanked: 1360 times
Re: ERF for SCT 250 mm
Altair astro now has 160mm duo band (HA & CaK). They call it tri-band but in reailty CaK & CaH are the same for a DERF's FWHM.
https://www.altairastro.com/d-erf-energ ... s-71-c.asp
So you could do a 150mm full aperture frac, or you could go for a 7 inch frac and mask down to 160mm.
Note, these DERF still pass energy so you could still image with nearly any wavelength just at lower transmission, which is fine for filter systems that are loose FWHM like photosphere imaging filters (like 500~540nm).
Very best,
https://www.altairastro.com/d-erf-energ ... s-71-c.asp
So you could do a 150mm full aperture frac, or you could go for a 7 inch frac and mask down to 160mm.
Note, these DERF still pass energy so you could still image with nearly any wavelength just at lower transmission, which is fine for filter systems that are loose FWHM like photosphere imaging filters (like 500~540nm).
Very best,
- mami813
- Im an EXPERT!
- Posts: 246
- Joined: Tue Feb 18, 2014 5:37 am
- Location: South Korea
- Has thanked: 148 times
- Been thanked: 234 times
- Contact:
Re: ERF for SCT 250 mm
It is said that 240mm erf filter is currently in stock in Altair.uk.
I exchanged mail a few days ago.
This is the contents of the mail I exchanged.
``Hi there, the 240mm Ha only D-ERF would be £2000.00 and the clear aperture would be about 230mm (you would need to hold the edge by 5mm). We have one unit left in stock and they take about 2months to make.``
I exchanged mail a few days ago.
This is the contents of the mail I exchanged.
``Hi there, the 240mm Ha only D-ERF would be £2000.00 and the clear aperture would be about 230mm (you would need to hold the edge by 5mm). We have one unit left in stock and they take about 2months to make.``
- marktownley
- Librarian
- Posts: 42269
- Joined: Tue Oct 18, 2011 5:27 pm
- Location: Brierley Hills, UK
- Has thanked: 20424 times
- Been thanked: 10242 times
- Contact:
Re: ERF for SCT 250 mm
Interesting, good to know thanks.
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!