Solar White Light - first attempt!

[MjrTom]

Hello all.

This is my first attempt at a bit of white light solar imaging using an ED80 with a Baader Hyperion Zoom used afocally at 20mm focal length.

This is a single frame image recorded using a Canon DSLR.

Exposure set a 1/200 second using Baader visual solar film.

I am struggling due to the field curvature of the eyepiece in relation to the film plane meaning that the centre of the disk is sharp but the edge is not. I quite like it as a very first attempt at least.

Need to decide how to adjust the colour balance so this time I have done it the easy way and just set the temperature to 10,000 Kelvin in the EOS Utility software.

I also took a 5 second video using the DSLR again set at 640x480 @ 50fps. Just need to convert it into a format that Registax can use and will try stacking the frames to see if it improves on the seeing conditions.

Comments, critique and any suggestions always welcome

[Bizibilder]

Once you get your focussing sorted (its not far out!) you should be on your way to getting some very good results. Don't forget that at the moment the Sun is quite low in the sky and there is quite a bit of haze around so that may be having an effect on the sharpness of your image. This morning, for example, I took 100 frames and Registax only "accepted" 29 of them!

You may want to try stacking some images - the final result will be better than any single frame (unless you are extremely lucky). I take and stack JPEG's - usually 60-100 of them and get results that I'm quite pleased with .

I use "daylight" (the sun symbol) for my white balance - seems to work well with the Baader film. The other trick is to slightly under expose, its much easier to brighten things up in post-processing than to try and rescue an over exposed image. Hope this helps.

PS Your image is South at the top - try: http://www.solen.info/solar/ to help with orientation and spot numbers.

[MjrTom]

Thanks Bizbilder

I have uploaded a crop of the sunspots I focused on to show that the focusing is not too far off but the field curvature is quite pronounced....

I am struggling to stack the .mov file even when converted to AVI.

Are you saying I should try and stack just 60-100 photos as opposed to trying to use the video?

I shall try the different white balance setting as you suggest.

Viewing conditions are not great today with quite a bit of cloud mixed in with high cirrus cloud in between.

Trying to nail the technique so that when conditions allow I can get something worthwhile.

[Bizibilder]

I like the result from the video! It seems to be pretty much in focus all over.

Yes, I just take 60-100 single pictures and stack them - for full disc images (I see you've found my images from today!) - but I do use an SPC900 webcam and 2x barlow to get spot close-ups. The full disc images are cropped to 1024x1024 Px for the forum and thus lose quite a bit of detail. The spot close-ups are as they come off the camera (with a little edge crop to get rid of artifacts from Registax).

My scope is 1000mm focal length so you may want to try a Barlow on the ED80 to get a bigger image. That will eliminate problems with the eyepiece you are using - the cheap Skywatcher barlow is the one I prefer to use, even though I have a so called better one!

Are you using RAW for the still pictures? I also get the pinkish colour from using RAW and the Baader filter which is why I prefer JPEG - even with the losses due to image compression - overall I feel I get a better result with it.

[MjrTom]

Thanks again

I shall keep persevering and trying the suggestions you have given

I also have a 1000mm 4 inch achro which I have yet to make a solar filter holder for so that might be another option when I get round to doing that as well.

I was shooting in RAW then changing the white balance to try and give it an orange hue for aesthetic reasons but its not really worked very well. Will adjust the RGB channels in photoshop instead.

It was your images I saw this morning that gave me the inspiration to have a go at imaging what I was looking at through my eyepiece

I think North is at the top, looking at the link it looks like left and right are flipped. I was using a diagonal which should give the right orientation north and south but east and west are reversed.

But I maybe wrong lol

[spaceboy]

Looking good Mark. I had a try at the sun in July http://stargazerslounge.com/imaging-solar/150334-my-humble-attempt-todays-sun.html

[MjrTom]

Thanks Nick, Its not too shabby but loads of space for me to improve upon it with practice.

[Montana]

Lovely pictures, there is some excellent detail.

Alexandra

[MjrTom]

Thanks Alexandra

If the clouds ever clear I shall give this another try, maybe prime focus this time instead of eyepiece projection to correct the field curvature

[Cschur]

Hi Mark - Just some quick suggestions, First since you are shooting afocally, consider selecting a wide field eyepice with a flatter field such as a nagler or plossl. Youll save yourself a lot of heart ache later. Otherwise, you might shoot several shots with different parts of the field in focus and combine them in layers with the eraser tool to get the whole disk at once in focus. Crude, but it does work. Many full disk white light imagers use a yellow "photo filter" to color thier suns. try that in photoshop or whatever you have.

[RikM]

Love the close-up. The detail in the penumbra is great.

I also take single shots and stack them for my full disc images. My normal settings are ISO800 and 1/1250sec. I find I get better results (sharper images) taking 30-40 of these in RAW rather than lower ISO and longer exposures. Don't really know why, I think it freezes the seeing.