capturing mighty sun

[lostinsydney]

to all pros out there i need your opinion and advice on capturing sun. do i need a B+W 120 ND filter and pair of oakleys? anything else?

also any suggestion on technique and tips are welcome

ive got d200.

sorry if im asking a too obvious question.

thanks

[Killakoala]

Get yourself to a telescope shop and get a proper filter. An ND will not do the job sufficiently. You may have to get a larger filter than your lens will fit, so you may need to compromise a bit. An ND will just give you a big yellow ball. A proper sun filter ($~150) will allow you to see black spots and a very expensive (type/name escapes me) filter will allow you to see surface texture. But the latter filter costs a lot, in the thousands depending on the size.

Also factor what lens you are going to use. Ideally you should be aiming for about 1000mm focal length which will give you a not-too-small crop.

I use three lenses for sun photos depending how much time i want to spend setting up. A 500mm Mirror lens with a 2x teleconvertor, a 4.5 inch Newtonian telescope which gives me about 1250mm and an 8-inch Schmidt-Cassegrain telescope which gives about 2000mm.

The following images of the 'Transit of Venus' were taken with the 500mm and 2x TC as i needed to be very mobile due to cloud cover. (There were no large perceptable sun spots on this day)

This image shows a full-frame as you would expect from the 500mm and 2x TC. Also consider the crop factor of the D70 i used to shoot it with, which makes the focal length about 1500mm.
http://www.stevekilburn.com/photos/9612648-L.jpg

Four cropped images with the same setup.
http://www.stevekilburn.com/photos/9612649-L.jpg

Good luck.

[Gordon]

You need a proper reflective filter that stops most of the light before it reaches the lens, I use a Thousand Oaks
http://www.thousandoaksoptical.com/ full aperture for my 25cm Newtonian telescope and it works well. Its got a few pinholes in it these days, its over 20 years old, but still works fine. It gives a yellow/orange sun.
The cheap way out of it is to use a Mylar solar filter, if you dont mind a blue Sun. Either of these will let you see darker sunspots and some other markings on the face of the Sun.
http://science.nasa.gov/ssl/pad/solar/feature1.htm

Talk to the guys at Binocular and Telescope Shop in Sydney to find out what is suitable for your setup.
https://www.bintelshop.com.au/ search for solar filter... but you will still have to talk to Mike or other staff about your exact requirements. (tell him I sent you )

Hydrogen Alpha (H alpha) filters are the expensive filters Steve was thinking of, the narrowest of them (thousands of A$$$) give a bandpass only about 1 Angstrom wide and let you see all sorts of wonderful solar surface details, flares etc, and prominences reaching out into space beyond the limb of the Sun. Less expensive ones with a bit wider bandpass will let you see the same thing, but with a lot less contrast.

My Transit of Venus pics are at: http://members.ozemail.com.au/~loomberah/transit.htm
The animation pics are a bit dodgy, I had some light leaking in the back end of the scope and was in a rush to get the animation made, so didnt have time to burn all the light leak areas and blank areas from image rotation out of the images.


***DO NOT TRY AND USE AN ND FILTER BEHIND A FAST LENS!!!***

Gordon

http://science.nasa.gov/ssl/pad/solar/feature1.htm

[lostinsydney]

thanks a lot for the fantastic feedback. i’ll keep your suggestions in a safe place because i don’t have enough resources to do this in short-term but i’d love to try this. btw thanks for sharing the great photos!

for now maybe i could just settle for his weaker distant cousin, moon

thanks again
sumit