Flats - Sense check please!

[David Smith]

So, have been working on introducing flats into my white light full disk images and I think I finally have a work flow that works....but!

Normally I use PIPP to convert my CR2 raws (lights) into Tifs and at the same time crop and centre the Sun in a 2200x2200 frame. So I thought I will just give PIPP my CR2 flat data and all will be solved, er Nope. No longer can PIPP find the Sun in the frame and it rejects all my lights.

So, after much trial and error I have the following process which has finally given me an image I am vaguely happy with:-

PIPP - convert lights and flats from CR2 to Tif at original frame size.

R5 - Create BMP flat from flat Tifs

R5 - Stack lights using BMP flat (both at original frame size which makes things a lot slower)

Use my normal wavelets / gimp pocess to finalise / false colour the image.

So here is my image from the 28th. First one is the original (cropped in PIPP) and second one processed using the above steps. Generally I am happy with it but at certain zoom levels on my machine I can see a faint grid pattern??

Grid pattern did not appear in the post preview so am hoping it will not appear in the final post. Appreciate anyone who can take the time to view, download etc and let me know what they see / think. Equally any pointer anywhere in this process greatly appreciated (I may be making a silly mistake somewhere and making this much more complex than it need be )

Thanks

[David Smith]

Colour versions below as these show the benefit of the flats process better than the mono. Again, original first flattened version second.

Thanks all

[Steve Ward]

No sign of a grid from this end squire , looks great ... 

The Flats have all but eliminated the DB at half past two so they obviously work , I just tend to "mis-align" the mount these days , let the disc drift around the chip and let PIPP centre everything for me , that and a cleanish sensor works wonders ... mind you I'm kinda just playing at it these days ... 

Couldn't find a more worthy recipient for my 8000th post ... 

[Davey-T]

Downloaded and zoomed, no grid here.

Solar flats give me more trouble than DSO ones for some reason, don't know why, probably me

Dave

[David Smith]

Thanks both

@Steve - I have tried the "let the Sun drift around the frame" technique but still get a bit of a shadow hence the decision to spend some time getting flats to work.

Congrats on 8000 posts, I'm honored

[sooot]

lovely work david

[Montana]

They look very fine images to me, no grid on the image I downloaded :)

Alexandra

[Steve Ward]

No grid on the image I downloaded :)

Alexandra

Makes a pleasant change eh ... 

[Ewan]

Suntastic images again David, I have to expand my vocab, all these nice,splendid, fantastic quotes really don't express the gratitude I award you with every one of my comments..........................Ah ha that lot should do it.

It actually pays to have a slight drift in the mount I find with solar.

Surely if the mount tracked 100% accurately say with a sun spot under a dust mite wouldn't the detail of the sunspot be 'blocked' by the dust & not be in the final image ?

As I just 'drag & drop' my mount (not really drop believe me) I can't PA so I just point North(ish) then set the HC up, my flats are just outward de focussed middle of the sun ones BUT I have found a few times now where there is NO where to get a good flat using the sun's surface, sometime's the de focussed image on screen is too bright in the middle with shadows either end.

I am looking into a newer quick method to get a more even flat.

All in all Dave your images always make me smile as the sun should do, keep it up mate.

[David Smith]

Thanks all, glad they look ok on here. Will upload to Flick / Astrobin and just see if that works ok.

@Ewan Your too kind.

Yes, my mount definitely isn't polar aligned. I have some marks in the ground so that it is roughly aligned each time but the Sun was drifting south as I shot today. Flats for my white lights are done by removing the baader film filter and just shooting a bland area of the sky either inward or outwards of focus point.

For H alpha I have the problem of the Suns disk not filling the frame, even with a barlow in place. I may have to invest in a 3x barlow just so I can get decent flats!

[michael.h.f.wilkinson]

Looks good. Have you tried LR deconvolution instead of wavelets?

[David Smith]

Working on that next MIchael. Struggled to achieve a good result so far but I'm pretty stubborn at times so I am sure I will get it sorted in the end