Jonzky
super member
Reged: 05/10/08
Posts: 179
Loc: London
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I know that it would be more appropriate to post this in the filter section but there will be more experienced people here so... I recently got a CPC 1100 and a solar filter and quickly (more like in 20 seconds) realized it is pointless to view the sun without a Ha filter, I have done some research about it and realized I need a very narrow band filter but being in the UK I am finding it hard to find one... So here is one that I have found though it is quite pricey (£208).
Astronomik H Alpha Filter 2" Ref: 8H0051
The Astronomik H-Alpha CCD filter, is designed for CCD imaging of gas and planetary nebulae. Due to the narrow bandpass of the H-Alpha line at 656 nm, the filter provides maximal increase in contrast even under poor observing conditions. The 13 nm bandwidth allows us to achieve transmission as high as 97%--a value that is impossible to reach with filters of narrower bandwidth. With faint supernova remnants and planetary nebulae, the Astronomik H-Alpha filter often makes the difference between detecting the object or not. The filter blocks all unwanted light, especially the Mercury (Hg) and Sodium (Na) emissions from streetlights and the IR region where CCDs are often most sensitive. The optimal focal ratio for the use of this filter is between 1:3.5 and 1:6. The range of application is from 1:2.8 up to 1:15. Unlike other filters of narrower bandpass, loss of transmission with the Astronomik filters does not emerge until focal ratios of 1:2 or faster are used. You can, therefore, image objects within the whole field of view and not only in the middle.
I know it says its for gas and planetary nebula but its one of the only one I could I find in stock, Also I do intend imaging but also viewing. Does anyone live in the UK and know any websites?
Any advice would be appreciated.
Jon
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My Scopes:
CPC 1100
Lunt 60 Ha (B1200)
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Brought to you from the light polluted London
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Don W
Demi-God
Reged: 05/19/03
Posts: 15145
Loc: Wisconsin, USA
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The filters you are describing are NOT to be used for solar viewing. They are meant for imaging of HA features in deep sky objects. There is a thread discussing this issue at the top of this forum.
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Don Wyman
Obsession 18" f/4.5 #1166
W/Argo Navis DSC and Torus Primary
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atoptics
Pooh-Bah
Reged: 08/10/06
Posts: 1482
Loc: UK
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Sorry but it is *not* suitable for H-alpha solar viewing and would be dangerous to your eyesight to use. See the thread at the head of the page.
Solar H-alpha filters are very narrow band and come together with 'must use' infra-red and ultra-violet blocking filters. The entry level 'scope is probably the Coronado PST (see Telescope House site) but that might well change very soon with other suppliers entering the arena. Welcome to solar viewing - you will love it!
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Les
Optics Picture of the Day
Atmospheric Optics
TiltingSun
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25882
Loc: NE Ohio
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Quote:
Any advice would be appreciated.
Jon
That won't do what you want. 13nM is FAR too wide to be of any help with solar Ha observing or imaging. Even if you add a suitable energy rejection filter you'd need to be 100 times narrower (.13nM or 1.3 Angstroms) to see prominences, and narrower still for surface details.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
Meade 80mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Meade 152ED, 178ED F/9 "APO"
Meade 12" SCT
Teeter 20" F/3.8 truss Newt w/ServoCat
NJP, LXD700, CGE, GPDX/SS2KPC
ST-10XME, DSI Pro
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NickH
Post Laureate
Reged: 05/09/06
Posts: 3717
Loc: Wiltshire, UK (near StoneHenge...
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Your best option would be to get a dedicated solar scope of some kind. There are many available, or if you fancty splashing out a bit more, an off axis mask on the C11 and a good front mounted etalon and rear blocking filter setup (Solarscope/Coronado or Lunt)
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Tim Porreca
member
Reged: 10/16/06
Posts: 66
Loc: Phila., PA / Ocean City, NJ
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Jon,
It might be helpful to know how much you want to spend. A Ha filter for Solar observing is VERY expensive. There are white light filters which are cheaper.
Tim
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TOA-130
NP101is
EM-200 (for sale)
Mach1GTO on way
GM-8
SolarMax 90 <.5A
Lunt 60mm Ca-K
PST & Ca-K PST
SBIG ST-2000XM
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Uwe Pilz
sage
Reged: 05/16/08
Posts: 264
Loc: Leipzig, Germany
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The Coronado PST gives a good starting point for H-alpha observing the sun. I recommend this instrument. In thist case - H-alpha - a complete specialized telescope is much cheaper than a filter alone for an existing one.
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Uwe Pilz from Leipzig, Germany. Astronomical pages (in german, but easy to navigate)
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25882
Loc: NE Ohio
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Quote:
Quote:
Any advice would be appreciated.
Jon
That won't do what you want.
To be a littlle more helpful, the best Ha solar filter setup for a C11 is the Thousand Oaks .9A for about $900. Pricier than a PST, but much better performance and you already have the telescope.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
Meade 80mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Meade 152ED, 178ED F/9 "APO"
Meade 12" SCT
Teeter 20" F/3.8 truss Newt w/ServoCat
NJP, LXD700, CGE, GPDX/SS2KPC
ST-10XME, DSI Pro
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Jim Rosenstock
Post Laureate
Reged: 07/14/05
Posts: 4207
Loc: MD, south of the DC Nebula
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Quote:
... I recently got a CPC 1100 and a solar filter and quickly (more like in 20 seconds) realized it is pointless to view the sun without a Ha filter,
Actually, the so-called "white light" Solar filters can give very nice views of Sunspots-- when there are Sunspots to view. Unfortunately, we are near Solar minimum (see thread above) so there just aren't very many Sunspots these days. But this will be changing soon enough, so don't discard that white light filter yet!!
....and be warned: H-alpha viewing is the heroin of observational astronomy. Be careful! 
Cheers,
Jim
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Jonzky
super member
Reged: 05/10/08
Posts: 179
Loc: London
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I know, I can feel it drawing me closer to it, I have some good friends in NY and I could probably call in a favor and order a Ha filter to them and get them to ship it to me. If so what prices am I looking at for an OK filter? If so any website recommendations. (I am very stubborn, one I want something I have to get it)
Thanks,
Jon
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My Scopes:
CPC 1100
Lunt 60 Ha (B1200)
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Brought to you from the light polluted London
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colinsk
Carpal Tunnel
Reged: 01/17/08
Posts: 2170
Loc: CA
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As much as you want!
If money is not an object and you want to use your CPC 1100 I would look at a .5A filter form SolarScope or Day Star. You need to operate these at f/30 so you will need an off axis aperture mask with a ERF (energy rejection filter) and a telecentric barlow. Starting at around $2500 and up.
The nice thing is the filter can be used on a different scope if you decide to change. The drawback is there is a little warm up time before in is on band.
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Mahalo,
Colin Kaminski
Coulter 10.1" Dobsonian
TV-76/Baader Film White Light
LS60T/DS50/FT/BF1200
LDX-75
AT Voyager
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Jonzky
super member
Reged: 05/10/08
Posts: 179
Loc: London
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Quote:
As much as you want!
If money is not an object and you want to use your CPC 1100 I would look at a .5A filter form SolarScope or Day Star. You need to operate these at f/30 so you will need an off axis aperture mask with a ERF (energy rejection filter) and a telecentric barlow. Starting at around $2500 and up.
The nice thing is the filter can be used on a different scope if you decide to change. The drawback is there is a little warm up time before in is on band .
The price????? Wow I wasn't expecting those sort of figures, are there no cheaper filters on the market?
Thanks,
Jon
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My Scopes:
CPC 1100
Lunt 60 Ha (B1200)
---------------------------------------------------
Brought to you from the light polluted London
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25882
Loc: NE Ohio
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Quote:
If so what prices am I looking at for an OK filter? If so any website recommendations. (I am very stubborn, one I want something I have to get it)
Thanks,
Jon
The one I recommended before (and the only one that would work well on your C11) is here:
http://www.thousandoaksoptical.com/www/Products/halpha.html
You could make a Coronado SM40 work but the required blocking filter at that focal length is $1600 alone plus you'd spend about $1000 for the etalon and mounting plate. Resolution with that setup would be about 1/3 of what the Thousand Oaks would give you, but it'd be three times the price. No bargain.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
Meade 80mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Meade 152ED, 178ED F/9 "APO"
Meade 12" SCT
Teeter 20" F/3.8 truss Newt w/ServoCat
NJP, LXD700, CGE, GPDX/SS2KPC
ST-10XME, DSI Pro
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Jonzky
super member
Reged: 05/10/08
Posts: 179
Loc: London
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Thanks for the help John, I have looked and though the price is a bit deterring I will hopefully order it within a few days, I hope that if I get it I can be with my scope 24/7
Thanks for the help,
Jon
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My Scopes:
CPC 1100
Lunt 60 Ha (B1200)
---------------------------------------------------
Brought to you from the light polluted London
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 8801
Loc: Beatrice, Nebraska
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Quote:
Quote:
Quote:
Any advice would be appreciated.
Jon
That won't do what you want.
To be a littlle more helpful, the best Ha solar filter setup for a C11 is the Thousand Oaks .9A for about $900. Pricier than a PST, but much better performance and you already have the telescope.
Well, I might quibble on this a bit. A good DayStar 0.7 or 0.6 Angstrom T-Scanner will perform better on disk detail than the Thousand Oaks will due to its narrower passband. However, it is still a lot more expensive, so may be out of the gentleman's price range. Overall, for the "under $1000" H-alpha route, I still like the Coronado PST the best. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
Prairie Astronomy Club
http://www.prairieastronomyclub.org
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Ralph Marantino
Postmaster
Reged: 05/01/05
Posts: 6350
Loc: Old Bridge, New Jersey
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unless you haver an obsevatory or are Superman you will soon tire of dragging out a C11 every time you want a peek at the Sun.Get something small PST or Lunt do not buy used or you will probably be abused. Good luck. 
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Lunt H-alpha LS100THa/B3400
Rockland Astronomy Club
Member BAA Solar Section
Central Appalachian Astronomy Club
Astronomical League
DSPST,PST & 70mm Coronado Cal K telescope.2.2A
Zeiss 2 inch prism diagonal&Zeiss Zoom EP
2inch APM Herschel Wedge in a 94mm F7 Brandon
14.5 inch f4.2 Starmaster Dob(Zambuto mirror)
TeleView Genisis SDF with 1000 Oaks Glass filter
Zeiss 63mm f13.5 refractor 1000 Oaks Glass filter
Itty Bitty Solar Radio Telescope.
LHRIES Lite Solar Spectrometer
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Jonzky
super member
Reged: 05/10/08
Posts: 179
Loc: London
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I have considered that as well but I have carried it up the stairs, I have carried it into the garden over 10 times just to try and view sunspots, I doubt that I would get deterred using it.. Another question, would I get a better view with the C11? Also I have read some articles on solar viewing and they said that the lower the angstrom the more detail can be seen, If I do get the 0.9 Thousand oaks one, would there be a lot of detail to be seen and finally do the PSTs come with Ha filters if so what angstrom?
Thanks again,
Jon
--------------------
My Scopes:
CPC 1100
Lunt 60 Ha (B1200)
---------------------------------------------------
Brought to you from the light polluted London
Edited by Jonzky (06/24/08 06:19 AM)
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Ralph Marantino
Postmaster
Reged: 05/01/05
Posts: 6350
Loc: Old Bridge, New Jersey
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a PST is a totally integrated H-alpha telescope cannot be used for anything else.I use to own a 1000 Oaks 1.5A filter on my C8 and it gave great views of prominences and no surface disk details,I do not know about the new .9A product but the one that I owned for 5 years was a quality item.Is your name Clark Kent by any chance? PS this is the Celestron/Losmandy G11 that I will use for y 200mm Lunt telescope.
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Lunt H-alpha LS100THa/B3400
Rockland Astronomy Club
Member BAA Solar Section
Central Appalachian Astronomy Club
Astronomical League
DSPST,PST & 70mm Coronado Cal K telescope.2.2A
Zeiss 2 inch prism diagonal&Zeiss Zoom EP
2inch APM Herschel Wedge in a 94mm F7 Brandon
14.5 inch f4.2 Starmaster Dob(Zambuto mirror)
TeleView Genisis SDF with 1000 Oaks Glass filter
Zeiss 63mm f13.5 refractor 1000 Oaks Glass filter
Itty Bitty Solar Radio Telescope.
LHRIES Lite Solar Spectrometer
Edited by Ralph Marantino (06/24/08 07:07 AM)
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NickH
Post Laureate
Reged: 05/09/06
Posts: 3717
Loc: Wiltshire, UK (near StoneHenge...
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A good compromise would be a front mounted etalon system, and rear blocking filter, that you can add to a smaller or larger scope (using off axis mask on the larger one).
Lunt, Solarscope and Coronado all make these options
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jrcrilly
Refractor wienie no more
Reged: 04/30/03
Posts: 25882
Loc: NE Ohio
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Quote:
Another question, would I get a better view with the C11? Also I have read some articles on solar viewing and they said that the lower the angstrom the more detail can be seen, If I do get the 0.9 Thousand oaks one, would there be a lot of detail to be seen and finally do the PSTs come with Ha filters if so what angstrom?
Thanks again,
Jon
Hi, Jon.
I'll take those in reverse order. The PST is specified as "less than 1 Angstrom" and the several I've owned were significantly over .7A so I'd expect it to be about the same bandwidth as the TO filter. You'd be able to see good prominence detail and some surface features at that bandwidth. The C11/TO filter combo would greatly outperform the PST on proms because to really enjoy those you want to crank up the magnification and get inside 'em. The PST is OK to 50X or so, but with a 4" ERF on your C11 150X is easy and 200X is possible on a "good seeing" day.
David mentions above that there are high-quality rear etalon systems available with narrower bandpass and he's correct. I didn't mention those because they are expensive, but they will outperform the TO filter in a big way.
The common front filter systems can be made to work also but the price of blocking filters increases with focal length and at 2800mm on the C11 you are on the wrong end of that scale. Those can be economical setups for use with short focal length refractors but for long focal lengths a rear etalon is preferred.
If you wanted to bump up in price there is another alternative - Coronado has their dedicated 60mm .7A telescope on sale for about half price. $2000 gets you a front etalon (no sweet spot) with more aperture than a PST (meaning more magnification is possible) and narrower bandwidth (meaning better surface detail) than either the PST or the Thousand Oaks.
Or you can wait to see how the Lunt 60mm works and if you like that you can probably get one next year for a price between those two. Internal etalon like the PST (possible sweet spot issues) but narrower than it or the TO.
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John C
Urban Observatory
A&M/Astreya 76mm F/6 APO
Meade 80mm F/6 APO
TMB/LOMO 80mm F/7.5 APO
Meade 152ED, 178ED F/9 "APO"
Meade 12" SCT
Teeter 20" F/3.8 truss Newt w/ServoCat
NJP, LXD700, CGE, GPDX/SS2KPC
ST-10XME, DSI Pro
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