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Today I captured some digiscoping images of the sun and the moon. I used the self timer at 2 seconds to avoid any shake. Ixus 117HS on the PS-100 is zoomed to max of 20mm. The telescope is not at full zoom.
The unprocessed image left is resized from 4000x3000 to 1000x750. Nothing else. The moon is overexposed and false colour is clearly visible on the limb of this colour image. [Visible edge.]
This could well be the fault of the Ixus camera lens and the digiscoping method rather than the Vortex Razor.
The image at right is exactly the same original as the one above left.
I have darkened it in image handling software to adjust the overexposure. A mere touch of sharpening in PhotoFiltre7 adds some crispness. The false colour is still there on the limb. A violet wash covers the whole lunar surface.
While just acceptable, I would not consider this a very sharp example of a lunar image.
The Manfrotto 500 head suffers from the same problem as every other when it mounts the weight well above the vertical axis. Which means that the balance changes with pointing altitude. [Or attitude if you prefer.]
Point very high or very low and the weight of the digiscoping telescope system wants to travel downards. Finding the right balance is a matter of sliding the dovetail plate back and forth in the head. Which would be fine if the standard 500PLONG plate wasn't so short. Just as short as the head itself. And why not for "normal" horizontal use?
So I have ordered a 20cm long plate. A 357PLONG will allow rapid adjustment of the balance when I tip it all up high to capture the moon or the [PROPERLY FILTERED] sun. Or even circling birds of prey, high overhead. A very common sight around here.
The Manfrotto head has a friction adjustment to compensate for imbalance but that makes it far more difficult to steer the telescope easily. An alternative would be to add counterweights on long arms to being the center of gravity down to the tipping axis of the head. But who wants to carry heavy counterweights to a lake? A spring or even elastic can provide a lightweight, dynamic balance system but needs constant adjustment depending on the tipping angle.
Point very high or very low and the weight of the digiscoping telescope system wants to travel downards. Finding the right balance is a matter of sliding the dovetail plate back and forth in the head. Which would be fine if the standard 500PLONG plate wasn't so short. Just as short as the head itself. And why not for "normal" horizontal use?
So I have ordered a 20cm long plate. A 357PLONG will allow rapid adjustment of the balance when I tip it all up high to capture the moon or the [PROPERLY FILTERED] sun. Or even circling birds of prey, high overhead. A very common sight around here.
The Manfrotto head has a friction adjustment to compensate for imbalance but that makes it far more difficult to steer the telescope easily. An alternative would be to add counterweights on long arms to being the center of gravity down to the tipping axis of the head. But who wants to carry heavy counterweights to a lake? A spring or even elastic can provide a lightweight, dynamic balance system but needs constant adjustment depending on the tipping angle.
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