Barlow Recommendation

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
Post Reply
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Barlow Recommendation

Post by Jordan Konisky »

Would appreciate a recommendation for a high quality Barlow for solar imaging. My setups include SW ED100 with Baader Astrozap film for WL and Lunt B1800 Ca-K filter, ZWO 1600MM camera, and 50mm mask (or not). I know that the Baader and TV Barlows are highly recommended. Would a 2X 1.25" Barlow lens be most appropriate? Thanks for any advice.

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
User avatar
DeepSolar64
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 18823
Joined: Thu Sep 05, 2019 12:19 am
Location: Lowndesville S.C.
Has thanked: 17572 times
Been thanked: 16694 times

Re: Barlow Recommendation

Post by DeepSolar64 »

I use a Meade Coronado Cemax 2x barlow. It does great. I have no complaints about it. The manufacturer states that it's coatings are optimized for the Ha wavelength. It's a 1.25" size.

James


Lunt 8x32 SUNoculars
Orion 70mm Solar Telescope
Celestron AstroMaster Alt/Az Mount
Meade Coronado SolarMax II 60 DS
Meade Coronado SolarMax II 90 DS
Meade Coronado AZS Alt/Az Mount
Astro-Tech AT72EDII with Altair solar wedge
Celestron NexStar 102GT with Altair solar wedge
Losmandy AZ8 Alt/Az Mount
Sky-Watcher AZGTI Alt-Az GoTo mount
Cameras: ZWO ASI178MM, PGR Grasshopper, PGR Flea
Lunt, Coronado, TeleVue, Orion and Meade eyepieces

Image Visual Observer
" Way more fun to see it! "
EGRAY_OBSERVATORY
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6871
Joined: Mon May 18, 2020 4:45 pm
Location: Essex, S.E.England
Been thanked: 4900 times

Re: Barlow Recommendation

Post by EGRAY_OBSERVATORY »

Hello Jordan

https://astronomy.tools/calculators/field_of_view/

is really the best place to see what all sorts of Barlows, Focal Reducers and cameras can do for almost all specific telescopes. Spend a few minutes trying all the variables, which will then show what can be achieved...

Much depends on what you wish to see close-up etc., or image too.

Numerous choices of cameras, etc etc...

I certainly would recommend the TeleVue Barlows as I use, although I have in the past used the Cemax Barlows on other persons scope, so all a good acquisition. Ideally, you get what you pay for, but some are perhaps more appropriate for Solar/Lunar use...

Best Wishes
Terry


User avatar
Montana
Librarian
Librarian
Posts: 34563
Joined: Mon Oct 17, 2011 5:25 pm
Location: Cheshire, UK
Has thanked: 17672 times
Been thanked: 8791 times

Re: Barlow Recommendation

Post by Montana »

I have a Celestron 2x Barlow Ultima and a Astro Engineering AC555 magnimax 1.6x threaded Barlow and both are great :)

Alexandra


User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Thanks folks for your suggestions.

The Celestron Barlow ultima is no longer made, In reading reviews, I see that it is a "shorty." Are there advantages of a "shortly" vs something like a standard TeleVue 2X Barlow which some folks have recommended for a set up like mine? Just wondering.

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
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Terry,

Thanks so much for sending along the calculator link. Spent some time this afternoon calculating scenarios. Tremendously useful in helping my think through combinations of parameters.

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
User avatar
marktownley
Librarian
Librarian
Posts: 42272
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 20438 times
Been thanked: 10245 times
Contact:

Re: Barlow Recommendation

Post by marktownley »

I use a 2x cemax and 3x skywatcher barlow, also the magnimax like Alexandra.


Image
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!
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Getting there.

So under what conditions would one choose a particular mag Barlow (say 2X vs 1.6X vs 1.3X)? Is it based on a general goal to reach, for example, f18 through a combination of telescope of, let's say, F9 scope, degree of masking, and mag of Barlow? Am I close to thinking about this issue in the right way?

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
EGRAY_OBSERVATORY
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 6871
Joined: Mon May 18, 2020 4:45 pm
Location: Essex, S.E.England
Been thanked: 4900 times

Re: Barlow Recommendation

Post by EGRAY_OBSERVATORY »

https://en.wikipedia.org/wiki/Barlow_lens
explains the techi-stuff Jordan.

In brief though, Barlows magnify the image in the EP or camera. 1.3X = little magnification.. 5X = large magnification...

Terry


User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Terry,

Thanks for your response.

I understand how a Barlow works. My question is more related to when to magnify 2x vs 1.5x in the context of matching to a particular mask aperture reduction or no mask at all when using my SW ED100 f9 telescope with either a WL or CaK Lunt 1800B diagonal module and a ZWO ASI1600mm camera. Is the goal always to get to f18 or are there other considerations?

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
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: Barlow Recommendation

Post by Merlin66 »

It comes down to aperture and camera pixel size (sampling, arcsec/pixel) and seeing.
My rule of thumb, under good seeing the f ratio should target x4 or x5 the pixel size. Ie if you have 4 micron pixels then f16 to f20.
If the scope is an f7 scope this would mean using a x2.5 barlow.
I use the Baader Hyperion x2.25 barlow (it has a handy T thread connection) on my ED80 (f7.5) and the ASI 1600. (3.8 micron pixel)
This would give me a sampling of around 0.8 arcsec/pixel.


"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
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Thank you, Merlin. This is exactly what I was looking for. What do you do under not so good seeing conditions? And what criteria do you use to distinguish good from not so good seeing conditions.

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
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: Barlow Recommendation

Post by Merlin66 »

Jordan,
The conditions I have even with “lucky imaging “ never give the resolution you see in some of the much better submissions.
When I ‘ve tried higher ratios the results have been worse than when f20 was used.


"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
User avatar
KMH
Almost There...
Almost There...
Posts: 990
Joined: Sat Feb 22, 2014 4:45 pm
Has thanked: 641 times
Been thanked: 725 times

Re: Barlow Recommendation

Post by KMH »

Jordan,

I've been very happy using the TeleVue Powermates with a Lunt 100 THa. If the seeing is decent I prefer the 4x, otherwise the 2x or 2.5x. I also have the 5x but that is a bit much for the Lunt and our usual seeing. The TVs have available adapters that replace the eyepiece holder and allow the video camera to be screwed rigidly into place. They also work very well for lunar/planetary imaging.

Kevin


User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Kevin

I do have 2X TV Powermate so will give it a try.

I am using SharpCap to capture from my ZWO ASI1600 and at full view (no ROI) am able to capture as 16 bit mono Ser files at about 5.0 FPS with no dropped frames. Can get a bit higher FPS when I capture as AVI files. These rates seem slow to me, but I am not sure what I should expect. Going to ROI enhances the frame rate as it should. Just wondering what rate you are getting with your own ZWO 1600 and, thus, how many frames do you usually collect for WL and CaK imaging.

I would welcome comments from others of you on this thread. I am being helped tremendously and captured my first CaK images a few days ago. Need improvement in the processing before posting on SCF.

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
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

My previous post should have been a Dear Merlin, not a Dear Kevin. I had already responded to Kevin.

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
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: Barlow Recommendation

Post by Merlin66 »

Jordan,
With my latest CaK setup - Vixen Custom 80M (80/910 = f11.4), x2.25 Hyperion barlow (=f25.6) and the ASI 1600 using FireCapture and SER files.
At f11.4 I used an ROI of 2736 x 2612 for a full disk, fps=11
At f25, I used full frame, 4560 x 2670, fps = 6
Similar result with the WL.
Ken


"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
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Ken

And lastly, how many frames might you capture at each of these? Do you set a time limit for capture or a number of frames to capture?

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
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: Barlow Recommendation

Post by Merlin66 »

I usually set the capture to 500 frames. This ensures that any change in seeing from the #1 frame to the #500 frame have minimal impact.
Usually 20% of the images used....but if the quality IS good then even up to 50%.


"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
User avatar
Jordan Konisky
Im an EXPERT!
Im an EXPERT!
Posts: 356
Joined: Thu Apr 18, 2019 12:08 am
Location: Verona, Wisconsin
Has thanked: 386 times
Been thanked: 270 times

Re: Barlow Recommendation

Post by Jordan Konisky »

Thank you Merlin and all of you who have participated in this thread.

Now, I just need the sun to shine so that I can put all that I have learned into practice. Stay tuned.

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
Post Reply