CaK, 03022019

[bart1805]

This morning it was quite good for a couple of hours. Sun is still very low.
Two images:

100mm ED f/9 - Baader Blue - Baader K-Line - PST#1 - PST #1 - ASI290mm

Sun_123338_Gain=60(off)_Exposure=6.2ms_Gamma=73(off)42763_imppgPS by bart moors, on Flickr

And with a Baader VIP Barlow, focal length about f/13 - f/14

Sun_112218_Gain=191(off)_Exposure=6.4ms_Gamma=64(off)44678_imppgPS by bart moors, on Flickr

I experimented today with a telecentric imagetrain, but back to the drawing table. Way to much reflections, no clear image.

20190203_142315_resized by bart moors, on Flickr

Thanks for watching.

[MapleRidge]

Nicely detailed CaK images Bart...well done

Brian

[bart1805]

Thanks Brian! With CaK it is even more difficult to find the right processing techniques than with H-alpa. Hope I can practice a lot in the coming months.

[marktownley]

Good images and nice to see some experiments going on too!

[Astrophil]

Bart, both images are great and I too like to see the experimentation.

Phil

[MalVeauX]

Lovely Bart, always happy to see some Cak!

Very best,

[bart1805]

Thanks guys!
It is interesting to try the imaging train with the telecentric, a Baader TZ-3. I think it is the same experiment Bob Yoesle is working on.

Total length of the train is 60 cm. First 14 cm are in the telescope to move the Baader Blue a bit further up the light cone. Distance from back lens TZ-3 to image plain is 24,5 cm. Train weighs about 1.120 gram.
Focal ratio with the Baader TZ-3 becomes f/27, so would use the Grasshopper instead of the ASI290mm. The ASI is more sensitive in blue than the Grasshopper, but the pixels are just too small.
To gather enough light, I think a focal reducer is probably necessary, but then the train becomes about 10-15 cm longer. Baader sells two interesting ones, a 0,4 and a 0,7 reducer. But never saw them on the secondhand market.

Build some other trains today, first one is where I use the Baader VIP before the PST filters. Curious if it will have any effect. Will be about f/18 so then I can use the ASI290MM.

[Montana]

Absolutely lovely to see this new AR close up in CaK I don't think there are any spots sadly, it must be a decaying region.

Alexandra

[MAURITS]

Lovely Cak images Bart ...

[Bob Yoesle]

Hi Bart,

Wonderful images!

The Baader 0.4 reducer is the "research grade" to mate with the TZ3 and restores the original f ratio / EFL of the system. Haven't had a chance to use it yet but looking forward to when the weather improves. Looks indeed like we're on the same path... The Chroma Tech CaK filter is supposed to work at the specified 0.1 nm in a collimated or telecentric system. When tilted it looks almost as good as a PST CaK at f9 (2.2 A) - so we will see what happens in a telecentric at ! f27. I will also be curious to see what the PST CaK filters do in the telecentric, but from your results (as well as my non-telecentric imaging) the reflection issues may have to be dealt with.

Again, great images.

[bart1805]

Thanks!
I read that Baader says that by using the 0,4 you can restore the original f ratio. But you would have to move the reducer a bit more back than the ideal position. Still doubting if I would go for the 0,7 or the 0,4. With the 0,7 it would be possible to achieve somewhere between f/17 - f/19. And that is about the ratio that seems to fit with the ASI290MM in CaK.
Reflections will be the biggest problem, next to the length of the train and the possible sagging. And then hopefully the effect on the PST filters is what we hope it is going to be.....

[marktownley]

I have the 0.7x reducer and it's a nice piece of kit.

[bart1805]

I have the 0.7x reducer and it's a nice piece of kit.

Yes, but quite expensive too. Just thought that first trying the Baader VIP to achieve f/18 and see how the ASI290 functions is the best idea before investing.
Or I could try the 2,5x power mate before the PST filters. Powermate with a T2 adapter, T2 extension and Skybender. 2,5x will go down to about 2x.

[ffellah]

Nicely done, Bart ! Is that the spicules layer ? If that is what it is, I do not believe I saw it before in CaK...

Franco

[bart1805]

Nicely done, Bart ! Is that the spicules layer ? If that is what it is, I do not believe I saw it before in CaK...

Franco

Thanks Franco. Yes, that is the "double limb". But it has been done before: Mark and Bob for example have taken much better images of it.
Most of the the time CaK images are processed in such a way that this layer is hard to see in the final image.

[David_The_Bears_Fan]

Top Ca-K images Bart, well done.

[eroel]

Bart:
Nice clean and crisp shots.
Best regards,
Eric.

[Carbon60]

Very nice images, Bart. Looking forward to seeing more as the season progresses.

Stu.