How can I get granulation on my images?

[AstroManDan]

Hi,

I use a Mylar paper filter and a glass solar filter, I am ok at imaging sunspots, but how can I get solar granulation on my images?

I have an SPC900, DSLR or DSI II to use.

Thanks

Daniel

[brianb]

I am ok at imaging sunspots, but how can I get solar granulation on my images?

It isn't easy.

First trick is to keep the exposure as short as possible. Your optics need to be clean and you need to get the focus bang on. I find reducing gamma to about 50% helps with focusing & produces raw frames which show granulation - you need there to be something for the stacking software to grab on to for alignment!

A green or yellow filter may help by reducing chromatic aberration which reduces contrast.

But I'm afraid the fact of the matter is that capturing granulation depends on having tolerably steady seeing - and it isn't always steady enough to allow granulation to be captured.

BTW I do know what I'm talking about. I'm now using a Lunt solar wedge but was able to get granulation pretty well using an ordinary solar film filter. The glass filters don't work as well as solar film, in my experience - actually the Zeiss glass solar filters are pretty darned good but, since they're 20x the price of the the Orion / Thousand Oaks ones, you're unlikely to have one.

2010 Apr 01, 1549 UT. WO FLT 110, Baader solar film, x4 Imagemate, Imaging Source DMK21 camera.

[steppenwolf]

As Brian has shown, it most certainly can be done but the secret is good conditions and slightly under-exposing your images to ensure that you don't blow out the detail. This was my earliest experiment (2007) with white light solar and I would process the colours differently now but I captured some reasonable granulation using an EOS 300d prime focus on Skywatcher .25 metre Reflector mounted on EQ6 SkyScan. ISO 800, 30 images X 1/800 sec, stacked in Registax, WB set to auto. Solar filter using Baader Solarfilm.

[Merlin66]

As has been said:

Good, like "excellent" focus; steady seeing conditions and short exposures.

I find a Baader Continuum filter helps ( or a green filter)

Oh and lots and lots of practise!!!!

Ken

[AstroManDan]

Thanks for all your advice.

I do have a Baader Continuum Filter so I shall give that a go.