Quote:
Originally Posted by glend
I am considering getting the Hyperstar lense for my Edge HD8 and i am looking for some feedback from those that might have done this before. The attractions of f2 imaging are significant. I would be purchasing a ASI non-cooled OSC camera to use with this setup, as cooling should not be required at f2, or is it?
Specific questions:
1. Can the 0,79x reducer corrector still be used or is this just overkill or wrong, at f2.
2. I assume guiding is not required at this speed, but on faint targets i could see a need but probably a simple guidescope would suffice?
3. Do camera cables crossing the front affect image quality, or induce diffraction spikes?
Any general advice?
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Any obstruction (including the central obstruction) will reduce contrast/cause scattering and
yes the cables, just like a spider
will cause some degree of diffraction (spikes), BUT, it should be possible to minimize these somewhat.
If there are seperate cables for power and data, try stacking them one behind the other. You could even go all out and un-sheath the cable by removing the
outer insulation and then make the multicore cable inside in to a one-behind-the-other configuration (like a flat cable) and minimize intersection with the light path by placing it on edge. Although it is a possible minor risk, as some cables (esp for data or higher frequencies) are designed to operate as twisted pair for low impedance and may not like this. You'd soon see based on any signal degradation.
Also you could experiment with how the wires cross the light path: One straight run, A pair in opposite directions, curved etc.... There are many simulations of this effect to help give some initial guidance, but for me I would try one straight run as it appears to scatter the least, with 2 "dashed line" diffraction spikes in simulations I've seen. The U shaped types are also a good contender. I will try to post one if I find it.
Best
JA
EDIT: Added link, but not the one I was thinking of/looking for....
http://www.astrosurf.com/viladrich/a...iffraction.htm