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Lunt CaK B1800, inside visual inspection

Posted: Mon Mar 12, 2018 8:38 pm
by allhoest
Hi!
I just bough a one of these CaK; here is the first inspection.
CS
Alex


The filter, side and top views

Image
Image



The diagonal assembly.
The allen heads are metric (!).
The screws were not tight fasten; some were even lose. Why? For any mirror compression issues? The mirror is fixed by some material, glue-foam probably. It can freely move, expand.

Image



The diagonal itself is manufactured from a plain bloc.

Image



My fear was that the mirror would be somehow treated, for dimmer reflection, like the blocking filters of coronado.
I have no real mean to measure the reflected flux, but while pointing the mirror toward the sun, plenty of light is reflected.

Image



The front filter.
Sorry, I didn't feel the need to dismantle it…

Image



The front assembly can be simply unscrewed. No need to take out the allen screws. It is a T2 thread.

Image



The view to the intermediate filter shows some deposit on it. It looks terrible on the picture, because of the angle of view. But as we will see later, we can see something through it.
Finally, maybe I should dismantle these front assembly filters, for inspection.

Image



The connecting part of the front assembly has an aperture of about 18mm

Image



The rear assembly shows the 3rd filter, hidden behind the 1.25" adapter.
The thread is again the friendly T2

Image



The view through the front assembly shows a purple cast, in accordance with the curve of these filters, posted on this forum
The picture is "quickly" taken with a smart phone.

Image



The view through the rear assembly shows the famous yellow-green cast, in accordance with the description posted on this forum
The picture is "quickly" taken with a smart phone.

Image



For reference, here is a picture taken through a Baader K-Line
Strong prefiltrer, isn't it …

Image

Re: Lunt CaK B1800, inside visual inspection

Posted: Mon Mar 12, 2018 9:00 pm
by marktownley
Thanks for the inside view Alex

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat Mar 31, 2018 9:15 pm
by allhoest
So, I gave a try with this CaK filter. I used a NP101 for this first light.
First, with no barlow, but then I had only phantom reflections:
Image

Then I used a barlow. Results are here:
viewtopic.php?f=4&t=24259


CS
Alex

Re: Lunt CaK B1800, inside visual inspection

Posted: Fri Apr 06, 2018 8:48 pm
by Charon_X
The Lunt CaK module have a serial number ?

Re: Lunt CaK B1800, inside visual inspection

Posted: Sun Apr 08, 2018 3:18 pm
by allhoest
There is no serial number on mine.
But as we know that there are variations in filter making process, that would be a good thing.

CS
Alex

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 1:22 pm
by TheSkyBurner
Allhoest can you repost the images of your lunt module onto this server so they dont get removed?

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:03 pm
by allhoest
Indeed, the picture are gone.
Here, I repost every description, one by one.
CS
Alex


===========================
The filter, side and top views

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:03 pm
by allhoest
The diagonal assembly.
The allen heads are metric (!).
The screws were not tight fasten; some were even lose. Why? For any mirror compression issues? The mirror is fixed by some material, glue-foam probably. It can freely move, expand.

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:05 pm
by allhoest
The diagonal itself is manufactured from a plain bloc.


My fear was that the mirror would be somehow treated, for dimmer reflection, like the blocking filters of coronado.
I have no real mean to measure the reflected flux, but while pointing the mirror toward the sun, plenty of light is reflected.

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:06 pm
by allhoest
The front filter.
Sorry, I didn't feel the need to dismantle it…

The front assembly can be simply unscrewed. No need to take out the allen screws. It is a T2 thread.

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:08 pm
by allhoest
The view to the intermediate filter shows some deposit on it. It looks terrible on the picture, because of the angle of view. But as we will see later, we can see something through it.
Finally, maybe I should dismantle these front assembly filters, for inspection.



The connecting part of the front assembly has an aperture of about 18mm

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:09 pm
by allhoest
The rear assembly shows the 3rd filter, hidden behind the 1.25" adapter.
The thread is again the friendly T2

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:11 pm
by allhoest
For reference, here is a picture taken through a Baader K-Line
Strong prefiltrer, isn't it …

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:15 pm
by allhoest
The view through the rear assembly shows the famous yellow-green cast, in accordance with the description posted on this forum
The picture is "quickly" taken with a smart phone.

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:17 pm
by allhoest
2018May26 - Additional notes

I couldn't remove the adapter holding the 3rd filter.
Indeed, the parts connected to the diagonal look to be glued.

Image

CS
Alex

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:18 pm
by allhoest
The view through the front assembly shows a purple cast, in accordance with the curve of these filters, posted on this forum
The picture is "quickly" taken with a smart phone.

Re: Lunt CaK B1800, inside visual inspection

Posted: Sat May 26, 2018 7:25 pm
by TheSkyBurner
thank you for the repost! very useful information here