Transmission measured by Philippe
Rousselle
The Schuler IR78 has a longer turn-on
wavelenght than the IR70. It gives a better difference from red
light, but is a bit difficult to use. It interest in comparison
with any shorter filter, such as 700 nm, is not completely
demonstrated...
INTEREST
- Infrared imaging of the planets
- Excellent image steadiness
PROBLEMS
- Relatively weak quantity of light
- Noticeable loss of resolution
Mars
18 november 2005 - Mewlon 210, Lumenera LU075M
Same details than with the IR70 with a lower resolution.
There is nonetheless a slight albedo differences on the
polar caps that are noticeably duller.
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Saturn
28 february 2005 - Mewlon 210, ATK-1HS
Because of the weak resolution, the filter doesn't look
interesting for Saturn. Use a 700 nm filter instead.
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Jupiter
13 may 2006 - Mewlon 210, Lumenera LU075M
Maybe more interesting on Jupiter - the typical aspect of
the planet is enforced in comparison with 700 nm filters.
The contrast looks increased also. However, the
difficulty of use makes those differences hard to detect
as the technical quality of the images is generally low.
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Venus
1st september 2004 - Mewlon 210, ATK-1HS
Venus does show details in near infrared, this has been
confirmed on many images taken since 2004. The contrast
of those features is however extremely low, so don't
hesitate using very deep IR filters. The 780 gives good
results but filters of 800, 850 or even 1000 nm are easy.
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