Sun in white light 29/9/14 - ST80, Canon 1100D. How to increase resolution?

[rodhull]

No fancy equipment here: I hooked my 1100D to my humble ST80 (w/ solar filter) using a T-ring, then used an USB OTG cable to plug to my Nexus 7 to control it. I used the app DSLRDashboard giving me an effective 7" LiveView screen on the tablet. Focused the ST80 at x10 and took ~100 frames at ISO 400, 1/4000 sec

There was a little bit of thin cloud the entire time, but nothing that looked intrusive so I used all 100 frames in Registax 6 with some histogram, contrast and wavelet tweaks. Finally chucked the output to GIMP to crop and give a little extra unsharp mask and added the false colour to the second pic.

I'm quite pleased with the result, but I'm wondering how to get increased resolution. This was the first time I've managed some fairly well-defined faculae, but I want more!

Obviously at prime focus, the solar disc is pretty small in the centre of the camera's sensor. My zoom eyepiece (a Seben 8-24mm - quite decent bit of cheap kit for visual use) has a T-thread under the rubber eyecup.

I also have a Baader 2.25x Q-Turret barlow which might be preferable to use, but I can't find a way of using this instead since there's no T-thread or anywhere else I can think of to attach it in the light-path with what I have at my disposal...

I'm loathe to put more glass in the way but I presume eyepieces/barlows are the only way to get the disc to take up more sensor space, and thus more resolution without using a longer focal length scope, but willing to be proved wrong!

Any tips?

[michael.h.f.wilkinson]

First of all: very nice shot!

I use my 2.5x Powermate or even 3x TeleXtender coupled with my 80mm F/6 scope. The Baader barlow should work. All you need is a 1.25" to T2 adapter like this one:

http://www.teleskop-express.de/shop/product_info.php/language/en/info/p201_TS-Adapter-von-1-25--Steck-auf-T2-Aussengewinde---Fokaladapter.html

A baader solar continuum filter can help adding contrast as well

[rodhull]

Cheers for that...

Flippin' heck - almost £100 for the filter!

I'll get one of those tubes first and try that I reckon...it'll help to achieve a focus earlier too I'd hope - I don't need an extension tube currently but the focuser is almost all the way out on the ST80...anything to firm things up a bit!

[michael.h.f.wilkinson]

With a barlow, you typically need much less back focus, so the focuser should be moved inwards when you use a barlow

[sooot]

great images

[Pete Presland]

nice images, good collection of spots!

[Luke]

Very nice shots.

[David Smith]

Nice shots. You could try a #56 green planetary filter as a cheaper alternative to the continuum filter. I've not used a continuum filter but have had some success with a #56.

[rodhull]

Thanks all for the kind words and advice. Just realised that I dated the post incorrectly - I took these on Sunday 28th. We can't edit posts/thread titles on here, right?

David: What other kit do you use to achieve your white light pictures? Do you connect your Canon at prime focus, or use any intermediate glass? There's a crispness in your images that is distinctly lacking in mine (although I suspect it's more than likely due to the longer focal length and quality of the Evostar 120 over my cheap-as-chips ST80?)

[Montana]

These are super shots :)

Alexandra

[rodhull]

Many thanks! I have a long way to go (and quite a lot of spending probably) before being able to get close to your images! Congrats on the APotY awards! Amazing stuff.