Sun in Ha 18-1-13

[DrRobin]

Freezing cold up north, but a nice patch of blue sky, so out with solar scope. I got the sun nicely aligned and started a capture of around 600 frames, but the wind was moving the scope so I decided to stop it and start again. 100 frames in to the new capture and the cloud came across.

Total capture was 130 frames, so I stacked 37 of them to produce the quick image below.

The sun keeps on coming out but it is so cold I had to pack up. Snow on it's way so that might be the last chance for a few days.

[Montana]

A super picture at least you saw it, just grey and trying to snow here.

Alexandra

[DrRobin]

Thanks Alexandra. I have been trying for the last three days. What I am most annoyed about is the first capture of 600 frames wasn't too bad but like a fool I over-wrote it rather than giving it a new filename.

It is sunny again now, but I am too cold to leave my desk again, slaving over a hot computer. If it stays clear in about an hours time I might give it a try through the glass window.

[michael.h.f.wilkinson]

Very sharp image. Grey here I am afraid

[Steve Ward]

Nicely done sir ,

I think you'll be the sole contributor today , snowing here now and for the next few days apparently . . .

Steve.

[DrRobin]

Thanks everyone. 30 minutes ago it cleared here, so I set my Lunt up inside my office and had time for a couple of captures through the window before the cloud came in. Unfortunately, the windows don't open so there is some loss of detail, just processing now.

5 minutes after the last capture it was snowing thick and fast and there is a nice covering on the ground now, so nice to be inside.

[DrRobin]

And finally a capture from my office through a double glazed window, minutes before it started snowing.

There is some loss of detail, but at least I managed to get the full disc and proms. Scope is a Lunt 60 and I stacked 550 frames from 1500 for the surface and 350 frames from 550 for the proms.

Looks like I might be breaking out the snow shovel now to get home!

[Montana]

I think that is an amazing shot through glass! :)

Alexandra

[DrRobin]

Double glazing that needs a jolly good clean to boot. Thanks for the kind comments, I couldn't face standing outside again and if I set my scope up in the office I can pretend I am working as well.

The other alternative was to prop the door open and stand in the entrance, but as we share the building with another company, I don't think that would have gone down well.

[allcart]

At least you got something Robin.

What is the dark patch at the bottom of the first set.?

How do you find the PT on the LS60. I have read a review and it sounded good, but as a user, what is your opinion.

[DrRobin]

Hi Allan,

It was cloud. The first image was only 35 frames from 130 and there was cloud across the sun the whole time.

The Lunt 60 with pressure tuner is very good. The pressure tuner tunes the Etalon by moving the plates apart using pressure rather than a tilt in the non pressure tuner model or the Coronado. The PT system is supposed to give finer control over the Etalon than at tilt. As the plates stay parallel I would have thought that a PT tuned Etalon gives a better more even filter but apparently not, just finer control.

All fine in theory, but I find that I can move the PT several turns before I notice much difference and when you are in a rush I tend to just twiddle it until I get a decent picture and then take images rather than fiddling with it to get the best image.

Anyway I decided that if I bought the tilt version I would regret it so went for the PT.

[allcart]

yes its a hard choice when you have used neither. Stephen Ramsdens review favoured the PT system, but getting more user input is always useful. I wonder about the focuser as well. Is the feathertouch worth the extra money, or does the crayford do the job well enough.

[DrRobin]

Hi Allan,

I bought the stock focuser. It is a little cheap looking on an expensive scope, but works well enough for a webcam and the 10:1 is smooth enough. Apparently if you want to put a DSLR on it then the Feathertouch is the one to go for, but for lighter cameras/eyieces the stock focuser is fine.

I understand that a Baader Steeltrack will fit in place of the stock focuser and I might upgrade at a later date as I have a Steeltrack on my C11 that I motorised.

In short I decided to go for the PT rather than the Feathertouch. If your budget will stretch to both then I would think about both, but it does add a fair bit to the bottom line. The one thing you can say about the Lunt 60, (or bigger) you seldom see them for sale on the second hand market, they must be keepers.

Robin

[allcart]

I think I will be imaging with a ccd as a dslr doesn't seem the best option for solar work. Not sure I could stretch to the FT and PT, and then buy a ccd and zoom lens. It scares me just thinking about the price.

[DrRobin]

Hi,

Out of the two I would go for the PT and drop the FT, the stock focuser is fine for medium loads. As for CCDs it comes down to personal preference, I like the DMK series so bought a DMK41 but there are other options. I would avoid a colour camera, you seem to get Newton rings or similar diffraction lines as an interaction between the Bayer matrix and the Etalon.

For imaging you also want to look at the B1200 blocking filter. The number is the size, B600 is 6mm and B1200 is 12mm. A B600 would be fine for a small chip ccd like a DMK21, but is probably a bit small for a DMK41.

Prices of these scopes do tend to be high, probably the specialist nature, the smaller volumes and the cost of making the Etalon, the ERF and the blocking filter. Scary indeed.

[KE400]

If your budget allows I'd go for the PT & FeatherTouch. I stretched for both and also use the FeatherTouch on my C11 so it doubles up the usage, pretty easy to swap between the 2 scopes too and very easy to use once familiar with the set up.

Like Robin, I can vouch for the Lunt and it's been my best purchase thus far giving great views and nice images too. They are pricey but you gets what you pay for as they say which in the Lunt's case is a fine solar scope.

Robin and I have very similar set ups and we both opted for the DMK's for the CCD option. Again there are cheaper on the market but I'm very happy with the results from them so worth the cost in my opinion if it's an option to you.

[Montana]

If you intend to do a lot of imaging then the pressure tuner is the way forward. The pressure tuned gives a more even field of view making imaging much better, the tilt tuning system will always give a sweet spot area. This isn't too bad when doing hi res imaging but if you want to do a lot of stitching images together then an uneven field can make it look like a patchwork quilt, unless you are good at doing flats.

Alexandra

[DrRobin]

That is what I would have thought, but I asked Ian King this when I was buying a Lunt and he reckoned there wasn't much difference, the PT system gives better control over the tuning. Perhaps the Lunt tilt Etalon has an exceptionally large sweet spot?

[sammy1075]

nice pics mate, havent seen the sun around here for months!!