Hello,
I am looking for a Lumicon prominence solar filter.
Thanks !
Christian

Hello Ronnie,
We are still on track for next Christmass :-)
Best regards
Christian

I love these old plates. Well done !

Hello Bart,
I like your filter support system :-)
I have made no progress on my side since I was busy on other things. I've got to get into this in June.
BTW, did you observe any temperature issue with the filter ?
Best regards
Christian

So did you find a significant improvement ?

Thanks guys :-)

The F/35 gives a narrower effective bandpass. The effective bandpass of a 0.3 A filter is about 0.5A at F/27 and 0.4A at F/35 :

I have a test image comparing both F-ratio somewhere on my website.

Excellent indeed !

Beautifull images and processing !

Nice set of images ! You can probably remove the 0.7 reducer next time.

Well done Christophe !
It looks as if the large prominence on the limb has some connection with some of the filaments from the sunspot ?

Well done Bart !
Is it with the change of distance between the lenses ?

This s quite a good start. On top of that the rotation on the solar sphere is visible.
What is the parameter you didn't find ?

Very nice disk indeed. The processing is very good.
May I suggest an orientation with the North to the top ?

Nice set of images !

Hello, This morning the large passing cumulus kept respectfully at a distance of the Sun for at least 2 hours. This was quite unexpected since the forecast said it was going to rain. The current two sunspots are pretty small though the surrounding activity gave nice views. http://astrosurf.com/vilad...

Hi, The rationale is as follows : - Let's call F and D the focal length and diameter of the telescope. For your Mak F/D = 10. - Let's call d the diameter of the etalon and of the collimating lens. We will come back latter to the case where the diameters of etalon and lens are different. - Let's call...

There is no free lunch the saying goes :-)

I would say basically the same as Marty and Valery, A 100-150 mm refractor is very easy to set up and operate. This is no need to check collimation. Usually, the seeing is fine with this range of aperture. With a 200 mm and above, you will be more dependant on seeing condition, proper collimation, e...

This is quite good Stu ! I found the processing very well balanced. You just need now to keep the 250 RC ready as often as possible in order to be there for the good seeing episodes.
BTW, could you share a pic or two of the Lunt mounted on the 250 RC ?

You can try some drops of teflon oil. Wait one or two days after you drop the oil, then try again.

Thanks Bob, I'd completely forgot this one too !
It seems that one (or even both) of the ERF can be replaced with a EO394-10 nm in 50 mm diameter which much benefit.

There is definitely a problem there. It is worth asking TS guys.

Excellent first light !
A 10"ERF might be of use for this scope.

The processing of the second image is quite good.
We were lucky to have this nake eye sunspot.

Thanks to all !
The seeing conditions were rather good on that day.