My OCD is showing again: I keep trying to improve my H-alpha imaging set-up. Every time I look at the ZWO 1.25" camera adapters they appear shiny inside. Though this rather depends on the angle of incidence and the light involved. Would a serious camera manufacturer really overlook this important detail?
The
internal surfaces are threaded and then [presumably] anodized. This
seems to reduce grazing incidence reflections, in white light, quite well.
Which is [arguably] what really matters in white light imaging. [Natural light
image from a window during overcast at Left. Flash close-up photo Right.]Note the close similarity between both left hand examples internally. At higher angles of incidence [flash photo on the right] the light must really bounce around. The light from a Neolux 'warm white' LED table lamp "domestic bulb" was brightly reflected at all angles of incidence but difficult to photograph successfully. So I found another, rather more manageable, light source:
The image at left is floodlit from just above by a Bosch [compact] 3 LED work light/headlamp unit. Note how completely different these adapters appear under different forms of illumination! This is about the same, internal reflectivity I see from sky light when the dome shutters are open. The exteriors appear blacker. More like the flash image at right, above.Does the colour of the incident light matter? Red is supposed to be more strongly reflected by anodizing. Could H-alpha [red light] contrast be improved by painting the interiors of these adapters matt black?
I really ought to remove the ZWO camera temporarily while I am imaging. Then take a picture of H-alpha red light passing through the adapter in a real life situation. Is there much scattering after the blocking filter unit? I have two. The original PST BF 5mm and the Lunt B1200S2 12mm to compare. It would be ice to know how they differ in practice. But first, I must remove the steady rain and heavy overcast! Grr!
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