Sol's Proms Today (5/4/08)

[sheeny]

I noticed some nice proms today, so got the PST and DMK out.;) I piggy backed the PST on the C8 and kept the covers on the C8 in order achieve balance on the CG5.:)

Because focus is so difficult I bracketted focus of subsequent videos. Each image is a stack of 100 frame from about 600 frames. The surface detail was captured at 60FPS, but the prom detail was captured at 30FPS to handle the longer exposure required.

Dennis' wavelet scheme applied in Registax 4 (1=20.1, 2=10.7).

The third image is a masked stack of the two images in PS CS3. All images colourised by deleting the G and B channels in PS CS3. No other processing.

Better than my last attempt (I do appreciate my Arctic Butterfly!:thumbsup:)

Al.

[[1ponders]]

Nice one Al :thumbsup:

Here's something you might want to try (I don't know how to do it in PS as I use Astra Image to process my solar ha shots), rather than deleted the green and blue channels, double the intensity of the red channel, leave green at one and reduce the blue to about 0.5 (or adjust each slightly as needed). That will reduce the intensity of the red and allow you to improve the contrast.

[h0ughy]

oh thats awesome well done Al

[sheeny]

Hmmm. I have an idea how to do that in PS. I'll give it a whirl.

In the meantime here are some more from today, some different captures and some different processing (mainly different wavelet schemes and different rejection criteria for stacking).

The larger scale images of the prom were captured with a 2.5x powermate in the train.

Al.

[sheeny]

A quick reprocess with G and B level outputs reduced.

The first is a masked stack of images 3 and 4. The second is a stack with image 3 over image 4 and the blending method changed to darken - it does a much better job if the limb interface but at the expense of contrast in both the proms and the surface detail. All stacks manually registered in PS CS3.

Al.

[seeker372011]

most H Alpha shots of the sun I thought wr usually false coloured..some nice shots there, I'd be happy

[sheeny]

Yeah, I suppose they are. That's why I thought deleting the B and G channels would give the closest to realistic colour. It certainly looks like what you see in the PST!;)

I think I've managed to change the colour by adjusting the level output of the B and G channels as Paul suggested, but I'm struggling to achieve any increase in contrast. Maybe I need to try increasing the contrast in the two images before stacking:shrug:.

Al.

[[1ponders]]

I like the first one using the modified processing. The prom looks great. I'd agree with that. The false colourization an colour balance is normally the last step in my processing. I guess for me I'm trying to achieve a look that would be what I would imagine the colour of a G type star would look like, even though it is only Ha light.

[sheeny]

Yep, I think that's my favourite too.

I had another play to see if I could increase contrast, but really struggled to maintain contrast with any layer blend mode I tried, so went back to masking. This image has increased contrast, normal blending, 100% opacity, but I used a pretty hard edged brush and the graphics tablet to cut in the edge of the mask... that didn't really work :P despite a lot of care and effort, so I used a small soft brush and 50% opacity to soften the limb interface a bit.

I think part of the problem is that I've colourised the images (as images in their own right) before stacking. The colour mismatch is a problem. Important technical tip there!;):lol: So, yes, I agree, Paul, colourise should be one of the last steps in processing.:rolleyes::whistle:

Al.

PS if you toggle between this image and the 1st one from the last batch, I think it's easy to see the normal blend mode is the way to go, with the softer brush for masking.

[[1ponders]]

I like that version Al. :thumbsup: :clap: The addition of the glow that looks like is is coming from below the horizon really adds to the realism. The whole image seems to glow now with a more 3D appearance. The first ones tended to look a bit flat, but that one is great!

[h0ughy]

wow that has some impact:thumbsup: Man i hope to be doing something like this after october (when my 60mm double pass Lunt arrives)

[sheeny]

Thanks, and thanks for the help and advice, Paul!:thumbsup:

Al.

[sheeny]

Thanks, Dave. I can imagine how much you're looking forward to getting your Lunt. I'm looking forward to seeing some images from it too! Should be good - double pass etalon and 50% more aperture!:thumbsup:

I must remember that phrase... "double pass Lunt"... could have purpose when trying not to swear!:lol:

Al.

[h0ughy]

Lol

[[1ponders]]

:lol: