Pages: 1 [2]   Go Down

Author Topic: Focus-stacking - an idea.  (Read 8871 times)

jerome_m

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 670
Re: Focus-stacking - an idea.
« Reply #20 on: February 01, 2014, 07:54:05 am »

I would like to use the best lenses which is LF-lenses in electronical shutters and the best camera which is a high res digital back. With a normal Sinar P2-3 I can of course let the front be stationary which is good for stacking.
Just moving the back standard is no problem, but for macrowork the movement of the back standard is too unprecise. I would like to move more carefully and in exact same steps every time.

Now that I understand what you really want to do, I have a much simpler idea. This is actually what astronomers do to turn the focus knob of their telescopes for fine-focus and repeatability: use a clothespin. The idea is to put the clothespin on the fine focus knob and use it as a handle to be able to turn the knob at fixed angles. You'll need to plan your shoot so that you always focus in the same direction to avoid mechanical backlash in your focussing device.

It looks too simple to be true, and maybe it is in your case, but it is worth trying. On a telescope, it works surprisingly well.



(From: http://stargazerslounge.com/topic/170510-200p-eq5-first-use-tonight/

Here a setup with a self-made handle instead of the simple clothespin. Obviously, the precision is increased if the lever is made longer:



(From: http://www.cloudynights.com/ubbarchive/showflat.php/Cat/0/Number/1965312/page/17/view/collapsed/sb/7/o/all)

Another one here: http://www.weasner.com/etx/techtips/2004/focuser.html.

There are also electric focusers for telescopes. They can probably be attached to your Sinar.
« Last Edit: February 01, 2014, 08:02:16 am by jerome_m »
Logged

henrikfoto

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 899
Re: Focus-stacking - an idea.
« Reply #21 on: February 01, 2014, 09:49:18 am »

Thank you!
That is very simple and interresting!
I will test it.
Logged
Pages: 1 [2]   Go Up