Ah. Thanks Mark.

Hi

It will vignette the image badly moving it right behind the etalon.

If you move it put it before the CCD.

I have done a full PST Mod and I am thinking of taking the blocker I do not use out of the abandoned PST and placing it in front of a small CCD camera for prominences set up.

Andrew

Hi Oh I see. You place the etalon at the position for the F8 lens so 160mm and by placing the 1.25GP right in front of the etalon it changes the F8 beam to F10 without vignetting the objective. The 1.25x and the Collimating lens are then -160mm in effect. If you want less glass replace the -200 coll...

Hi Merlin

Should the circle be the Barlow aperture x the magnification factor, 2x for 2x barlow, 1.25x for 1.25 barlow?

The ED barlow looks like 100mm as it gives 4x 200mm plus a bit before focus.

Andrew

Hi Because of the -200mm backfocus requirement for the collimating lens the barlow can be giving more magnification because it is further in than the designed back foucus to give the stated magnification. So you will get some vignetting. I have been using the element out of a ED Barlow to try to get...

I am told it is. I am lucky then. Happy Xmas.

Hi,

A second hand Quark Chromosphere came up on a UK Facebook page and I decided to buy it.

It was reviewed in Astronomy Now I was told so is this a good sample?

https://astronomynow.com/reviews/daysta ... index.html

Cheers. Andrew.

Hi

The T2 nosepiece for the eyepiece / camera has an undercut and is in a brass compression ring so wobbles. Need to sort out a better fitting arrangement.

First image with todays nice prom. Less detail than visual.



Andrew

Hi Waiting for AstroRod to modify a diagonal to hold my Omega Bobs filter. As the blocker for the PST Bodging it in a Celestron Moon filter, loose or missed screwed in. Photo before found position. Panasonic GX80. Micro4/3. The background looks OK to me. Is it? P1090003.JPG Finally chanced on right ...

Hi I appreciate my use of an ED Barlow and at F30 with a PST Etalon was not optimum but I could see as much detail as in Pedros image with a tad more contrast. I am retired and cannot justify a 180mm+ DERF and a Baader Telecentric Barlow to just observe optimally a few days a year. People image at F...

Hi At F28 you can remove the collimating lens from the front of the PST as its near enough to F-Infinity, or F40 for a air spaced etalon. The re-focusing lens will just about preserve the back focus from the PST. On a 127mm F7.5 with 2x ED Barlow element before PST with Collimating lens at the front...

Thanks.

Hi

Whats the design back focal position of the Baader 1.25x Glasspath to give that magnification?

Rod tested 2x Barlows at -200mm and they actually gave 4x.

Have you measured the image size without and with the Glasspath?

Andrew.

Hi Merlin,

I had a good look but cant find it.

Transmissions from memory were in the range 60-40%.

Andrew

Hi I now can use some bits for a 12" dobsonian. I lent the mirror to someone and they cleaned it without asking and took half the aluminium off! 'Home' aluminised at my first club and some pre-cleaning artefact in the coating it looked like. So might as well take it all off. Whats the best narrow ba...

Hi Are you using a 2" red filter as an internal ERF? My friend used one and forgot to check after adding a Barlow and cracked a red filter. Still useable though as not at focus and seemed to have clear cover glass holding it together. There are various Solar discussions on CN. A review of front DERF...

Hi There was a test of front mounted DERFs in CN and they pass quiet a lot of light into the telescope. Roughly convert a 6" to a 4" in terms of thermal load. You are better masking in front of the objective to get the required F10 for the PST. Silver reflective front. This stops unwanted light heat...

Hi I had a brief try on Thursday. Achieved focus with the PST collimating lens moved forward. All my 2" extensions and a 2" nosepiece was enough. 2" Baader 35nm as ERF. Just had Bobs filter 1 of two held loosely in a Celestron/Skywatcher moon filter holder. Tuned in OK. Two nice large prominences. B...

Hi We had a nice sunny day yesterday. So I had the Vixen mod out. Last time I tried various options including polarisers to try to improve the images. As I was out over the day I had to move the diagonal round for a best field and there did seem to be some benefit from 'clocking' the PST etalon with...

Hi Graphed out the PST, assuming 18mm clear aperture AKA Daystar and 2mm round 10mm Sun for prominences. The Moon filter front which turned up from somewhere at 16mm was exactly right to go after Bobs Comb Filter so explains why it nicely darkened the field. Need my two Chinese cheap Moon filter bod...

Hi With the moved forward primary to reach focus even with the PST Collimating lens moved forward will result in some primary vignetting. The best case is for the Lunt 110mm DERF to be in a 100mm diameter aperture cell. Using Mel Bertles Newtonian secondary field illuminator calculator: Mirror 100mm...

Hi First time copied the first picture a few times, and perhaps twice the second or one 'in the system'. Had two days out in the sun with the PST 'Combat' etalon. Followed by the Re-focusing lens in a Celestron Moon filter in a BF 48mm to 28.5mm adapter infront of a diagonal. The diagonal contains o...

Hi

The first picture is duplicated somehow but they are all there with the captions displaced underneath.

Andrew

Hi I am confused by the image inclusion here. The baffle over the secondary: P1050426.JPG The baffle from the front. P1050427.JPG The baffle refitted with Sika sealant. P1050433.JPG A baffle for the primary baffle made out of a cheap Barlow nosepiece from Rods bits box. P1050438.JPG Mounted as far f...

Hi Well theory and practice may not differ so much. Many people run Telecentric Daystars at F16 to F20 for seeing when F30 is optimum for the telecentric. How did you measure the temperature? A thermometer in the beam? The Baader will reflect most of the energy outside of its 35nm passband, and let ...