Barlowing Thoughts Anyone?

[Macavity]

Chucking it down here! So my thoughts returned 
to yesterday's (non event) "Barlow experiment"!
(Not too easy without any sizable Sun Spots?)

But, if I look at my 2x Barlowed Lunt 50 images,
it seems a *worthwhile* thing to do! I can easily
convince myself that this does show more detail
than e.g. any un-Barlowed images "enlarged"!

Bit of a nightmare to fit a Barlow into the space
a Lunt 50 Helical Focus allows, but did it finally!
I use the nose-piece of an Antares 3x Barlow...
Gives almost exactly 2x within the focus range!

That this doesn't equal QUARK images is clear...
It also seems *somewhat* "lesser" than 60mm
Lunt images... but "Ya pays yer money" etc.

But I am interested... re. Solar Imaging notably 
(HA or WL): What Barlow *LIMIT* (2x, 3x, etc.)
have you managed (OK scopes matter, but.)

My basic Skywatcher 2x performs surprising well!
But also thinking of upgrades... Do you have any 
notable Barlow preference for Solar Imaging?  

[David Smith]

Interesting thread Chris, look forward to seeing peoples responses. My experience is quite limited but for my Ca-K close-ups I use a Revelation 2.5x. I also have a Revelation 2x (from which I can remove the front element to obtain roughly 1.5x) and a Baader Q Turret 2.25x. The Baader works well with my PST (My Revelation 2.5x will not come to focus) and the Revelation 2x seems to work with all.

 

[xtreemchaos]

great post chris, in WL the best or highest mag ive had is with a 4x powermate and old faithfull "ar127l " f9.5 which when the seeing top notch " about twice a year"  was quite good. as for the quark , I find the 4.5 x barlow built in too much for the ED80, I use a 50% reducer to carm it down and give me fast exp. clear skys, charl.

[Tony G]

I use celestron x cel 3x with my lunt 60. My 60 handles it great. Its nice eyepiece.

[Dave In Vermont]

Chris / Macavity -

Un-screwing the Barlow-cell from the snout of the Barlow is an excellent trick that more people can benefit from knowing. I bought an Orion-Shorty 2X from Orion-USA over here for just this purpose. The Barlow-cell, by itself, when threaded into an eyepiece will give 1.5X to 1.6X. It has it's own protective-case in my eyepiece-collection.

I hadn't considered a 3X Barlow though. I think they're actually made by GSO, perhaps Synta, that whoever fields out the work from. I know who to ask! I know an utter 'Barlow-Nut' - like me with filters.

Thank you for sparking my interest. Off to find a good 3X Barlow that isn't as costly as my 3X TeleVue®.

Have fun!

Dave

 

[michael.h.f.wilkinson]

I almost always Barlowed my LS35THa, getting much more detail on the little DMK21 chip, even with just 35mm aperture.

The key as ever is to match the focal ratio of the optics to the size of the pixels of the chip used. A 2x Barlow gets you F/14 in the LS50. This would be fine for pixels of 2.4-2.9 micron (ASI178MM or ASI290), or thereabouts. For an ASI120 or 224 (3.75 micron pixels) I prefer to use F/18-F/25, and in the ASI174MM (5.86 micron) F/25-F/30 works best for me.

[Macavity]

Thanks for ALL of the above interesting thoughts!

I even drew a quick plot through Michael's "points" above.
With which I (naturally) agree! The "Barlowed Nosepiece"
experiment allowed me to get up to 4.0x with my Lunt 50.

So far only 10 sec glimpses of the Sun... But (predictably)
a TAD too optimistic for the 50mm aperture + 4.4 micron
DMK41 pixels? I might post image proof at some time!

@Dave... For what it's worth (by the day's end) I'll have a 
set of Antares "Twist Lock" Barlows (2x, 3x, 5x anyway)!
"#MCGA"? (Sorry, couldn't resist, my Canadian chums)

I sense they are GOOD "Medium Budget" Barlows tho!
(Two out of three) have detachable nosepieces... I am
working on the other one... Muahaha.
(Stuff I wouldn't risk with Teleview!)

Aside: I SENSE modest differences of pixel size, scope
aperture, Barlowing... can make quite a difference tho?
Still with some thoughts to my "Frankenscope" idea...