6 replies to this topic

[ToxMan]

Although Clear Dark Skies had seeing at 2 of 5, I needed to continue collimation and star tests after a week of clouds and several rain storms. The conditions were too poor for me to try fine adjustments using the focuser tilt ring, but secondary mirror adjustments were very close. Using Hasselah in Auriga, here are the at-focus airy disc, intra-focus and extra-focus test images.

 

 

And I captured Jupiter and Mars with 685nm IR Pass filter. Trying to get R-G-B filter data was futile for the seeing conditions. For Jupiter, the camera was set at 10ms, running video at 100fps, for 1 minute, stacked a third of the frames in AS4, and used the FFT denoise routine in WS, which is new for me.

 

 

For Mars, same filter except I wanted to confirm I could use a shorter shutter speed and faster frame rate without dropped frames. Camera was set at 4.8ms, running video at 205fps for 1 minute, AND no dropped frames. Similar processing as with Jupiter, adding de-rind.

 

 

I know it's late with Jupiter getting lower in the sky and Mars getting smaller. But this is good preparation for later. And this telescope still needs a little more adjustment. Thanks for looking

 

Paul

 

 

 

 

[ToxMan]

I thought of a question for the forum. Since WinJUPOS derotates image data, with a monochrome camera and capturing through filters, is there any reason not to capture Jupiter data for each filter for 60 to 90 seconds? That is short enough to not have rotational smearing, long enough for extra frames, and the software should align the individual R-G-B frames, right?

[Kokatha man]

I thought of a question for the forum. Since WinJUPOS derotates image data, with a monochrome camera and capturing through filters, is there any reason not to capture Jupiter data for each filter for 60 to 90 seconds? That is short enough to not have rotational smearing, long enough for extra frames, and the software should align the individual R-G-B frames, right?

...of course you can Paul!

[ToxMan]

Another question. Should a star test using a monochrome camera, be performed with no filter or a specific filter? 

[JMP]

I'd use red or IR pass for the best seeing. You can see you need a tweek in the star test you posted. I think metaquide recommends red or IR.

[ToxMan]

I used IR pass.  And, yes, it needs a little more adjustment. The secondary mirror screws are so tough to turn for a more fine result. Waiting for a little better seeing conditions. Thanks!

Edited by ToxMan, 17 March 2025 - 06:00 PM.

[ToxMan]

Another question...

 

Orion claimed in their literature that their quartz mirrors on the f12 Classical Cassegrain were good for transmission of IR, visible and UV wavelengths. But I am not finding data to back that up, nor a reason to doubt it.

 

So, in researching filters, for IR and UV filters, I have read Christophe Pellier's articles from "Planetary Astronomy," as well as many posts from John Boudreau. Lots of good information regarding filter selections for outside the visible spectrum for the subject planet.

 

Regarding visible light though, Astronomik and Baader seem to stand out for selecting LRGB filters for planets. Baader calls theirs, CMOS optimized. But there are other brands, obviously...Antila, Optolong, ZWO and others. My LRGB filter set was purchased from Orion over a decade ago. These could be a repackage product out of Asia.

 

Has there been some significant change in LRGB filters to consider? Are there real differences between brands? Lumicon, a California company, has filters...anyone use their filters for planetary imaging?

 

Thanks in advance.

 

Paul