Hello Everyone,
I've been off SolarChat for a few months recovering from a hip replacement. A few days ago my surgeon cleared me for all activities, so I thought I would try out my new ZWO 1600mm, new Lunt 1800 CaK diagonal in combination with my StarWatcher ED ED100 refractor for my first try at CaK imaging. It turned out to be a frustrating return to solar imaging.
I first tested the camera using a Baader WL filter and found that bringing the camera to focus required cranking the focuser down to within a cm from the forward stop. As expected, same result when I stopped down to a 50mm mask.
I next removed the WL filter and replaced the SW diagonal with the Lunt 1800 diagonal module. I was able to insert only half of the Lunt 1800 nose before it came to a stop up against an internal lip. This arrangement did not come to focus on my SharpCap capture screen. 2X Barlow or TV 2X Powermate had no effect. Suggestions?
Jordan
Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
- Jordan Konisky
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Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
- krakatoa1883
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
This is a well known problem of some (not all) SW ED refractors, a step inside the mobile tube that prevents inserting long 2" accessories. There is no solution other than replacing the focuser as I made with my own 100ED. I suggest a Baader Steeltrack focuser, this will solve the problem with the WL filter too.
Raf
My solar images and reports with articles on solar equipment
My solar images and reports with articles on solar equipment
- Jordan Konisky
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
Yeah, I thought this might be the case. Which model of the Baader Steel Track Focuser would you recommend for my SW ED100 refractor. The nose of my Lunt Ca-K diagonal is 9cm. I very much appreciate your explanation and suggestion.
Jordan
Jordan
Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
- krakatoa1883
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
The focuser is this one
https://alpineastro.com/collections/foc ... ck-focuser
together with the adapter for SW tubes
https://alpineastro.com/collections/foc ... -celestron
The adapter shall be attached to the tube by using of the same screws of the original focuser, it's a minute-long adaptation, very simple. The Steeltrack saves lot of backfocus compared with the original SW focuser, this will make the scope much more usable, particularly for imaging. No steps inside, the Lunt CaK nose can be fully inserted. The finder base in the image above is not included with the focuser, it shall be purchased separately.
Hope it helps
In the USA Baader products are sold by AlpineAstro, so you can order from this pagehttps://alpineastro.com/collections/foc ... ck-focuser
together with the adapter for SW tubes
https://alpineastro.com/collections/foc ... -celestron
The adapter shall be attached to the tube by using of the same screws of the original focuser, it's a minute-long adaptation, very simple. The Steeltrack saves lot of backfocus compared with the original SW focuser, this will make the scope much more usable, particularly for imaging. No steps inside, the Lunt CaK nose can be fully inserted. The finder base in the image above is not included with the focuser, it shall be purchased separately.
Hope it helps
Raf
My solar images and reports with articles on solar equipment
My solar images and reports with articles on solar equipment
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
Where abouts is the lip in the focuser tube?
http://brierleyhillsolar.blogspot.co.uk/
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
Mark,
The lip is 4.5 cm from from where the diagonal gets inserted. As I recall, a few days ago Alexandra mentioned such a lip in one of her refractors while trying to insert the her Lunt Ca-K diagonal.
Jordan
The lip is 4.5 cm from from where the diagonal gets inserted. As I recall, a few days ago Alexandra mentioned such a lip in one of her refractors while trying to insert the her Lunt Ca-K diagonal.
Jordan
Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
Is it midway along the draw tube or at the end? Can you post a pic?
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!
- Jordan Konisky
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
The lip is, in fact, a slight narrowing of the entire draw tube that begins 3cm from the end where one inserts the diagonal. It, thus, acts as a barrier to full insertion of the Lunt Ca-K 1800 diagonal.
Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
- Jordan Konisky
- Im an EXPERT!
- Posts: 356
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
krakatoa1883
I appreciate your taking the time to provide me with the details for the Baader Diamond Steeltrack Focuser and adapter. Pretty close to pulling the trigger on an order.
Jordan
I appreciate your taking the time to provide me with the details for the Baader Diamond Steeltrack Focuser and adapter. Pretty close to pulling the trigger on an order.
Jordan
Jordan -
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
SkyWatcher ED100 Refractor with Diamond Steeltrack Crawford Focuser
Celestron CG4 Equatorial Mount
Daystar Quark H-Alpha Chromosphere
Lunt CaK B1800 Filter Module
Lunt White Light Solar Wedge
ZWO ASI174MM, ZWOASI1600MM Cameras
- marktownley
- Librarian
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- Joined: Tue Oct 18, 2011 5:27 pm
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Re: Lunt Ca-K 1800 diagonal, ZWO160mm, SW ED100 focus issue
Ahhh, I understand. If it was right at the very end I was going to suggest cutting the very end of the drawtube off. If it's a taper only 3cm in this approach wouldn't work. I replaced the focuser on my ED80 for the same reason.Jordan Konisky wrote: ↑Sat May 15, 2021 3:03 pm The lip is, in fact, a slight narrowing of the entire draw tube that begins 3cm from the end where one inserts the diagonal. It, thus, acts as a barrier to full insertion of the Lunt Ca-K 1800 diagonal.
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!