Finding Focus for Lunt 35mm

[Claire Wardlaw]

Hello, I am so totally new here in the world of solar imaging. I have become the new owner of a Lunt 35mm and have been trying to focus for imaging with variuos cameras. The main one is my DMK 21AU618. I have had suggestions that i need to get the camera closer , and further away and I'm really not understanding what to do. I first followed the advice to put the lens part of a x2 barlow into the nose piece of my DMK...bringing it closer. My focus was still way out. Do I need, where would I get a shorter nose piece ..a different barlow, a different focuser than the standard one on the back of the B600? I am sure this is all very basic .....sorry for the level of my knowledge... HELP !!!!! The view is lovely but I really want to image too.......

Claire

ps links to items I may need or pictures of what to do would be most useful too.

[Kitsunegari]

for starters you need a "c-mount to 1.25' nosepiece"  attached to the dmk camera.

https://www.amazon.com/1-25-nosepiece-mount-adapter-FAP201/dp/B01HQR5NUG

 

Secondly, you need to pull out the lunt b600 diagonal outward about 1cm and lock it there with the thumbscrew.

 

Thirdly adjust the camera height while watching the screen, you should see the solar image become sharper as you pull the camera out.     You will noticeably see the solar image getting larger and dimmer if you go out too far away from focus.

 

The image will get brighter as you get closer to the focus.     Make sure your exposure level is at about 5ms and the gain is set to 0( or at least below 3).    if you are using too much exposure time/gain, the image refresh rate will be too long, and the over saturated image will always be blurry.  It will look like a solid white blob if your exposure is too long.

 

I hope this helps,  you may not need the barlow,;  i am fairly confident you just pull out the blocking filter a bit.     (i do not recall the ls35 having a focuser on it and it relied on the thumbscrew only)

 

 

[Bobby1970]

4 hours ago, Kitsunegari said:

for starters you need a "c-mount to 1.25' nosepiece"  attached to the dmk camera.

https://www.amazon.com/1-25-nosepiece-mount-adapter-FAP201/dp/B01HQR5NUG

 

Secondly, you need to pull out the lunt b600 diagonal outward about 1cm and lock it there with the thumbscrew.

 

Thirdly adjust the camera height while watching the screen, you should see the solar image become sharper as you pull the camera out.     You will noticeably see the solar image getting larger and dimmer if you go out too far away from focus.

 

The image will get brighter as you get closer to the focus.     Make sure your exposure level is at about 5ms and the gain is set to 0( or at least below 3).    if you are using too much exposure time/gain, the image refresh rate will be too long, and the over saturated image will always be blurry.  It will look like a solid white blob if your exposure is too long.

 

I hope this helps,  you may not need the barlow,;  i am fairly confident you just pull out the blocking filter a bit.     (i do not recall the ls35 having a focuser on it and it relied on the thumbscrew only)

 

 

I seem to recall a Helical focusser when I had the LS35. It's also a rotating one. So it will rotate your camera also. 

The advice regarding pulling the blocking filter/diagonal out is consistent with my experience with this scope.