16.10.20 AR2776 in dire seeing conditions.

[Rusted]

Glassy, wobbling, shaking, going in and out of focus.
I feel so shamed to share these.

16.10.20 11.00 BF1200 2.6x GPC bw 2.jpg (93.83 KiB) Viewed 629 times

16.10.20 11.12 BF1200 2.6x GPC bw 2.jpg (97.82 KiB) Viewed 629 times

BTW: With a 2.6x GPC on the '174 camera nose the etalon distance to focus was 23.5cm.

[ffellah]

These are actually very nice images, Rusted. Have you tried the in real time flat feature of Firecapture ? Mark T pointed it out to me and it dramatically improved my images.

Franco

[EGRAY_OBSERVATORY]

Well Rusted, under those weather conditions, you have actually produced some excellent close-up images.

Thanks for sharing
Terry

[dhkaiser]

Well done under those conditions. And we do have an interesting AR.

[Rusted]

Thank you all for the kind words.

I use SharpCap rather than FireCapture.
So "real time flats" are outside my range.
I have tried flats in SharpCap without making serious progress.

[MAURITS]

Well done Rusted!

[DeepSolar64]

I would be proud of these!!

[MapleRidge]

The images turned out well despite the conditions you mention

Brian

[marktownley]

Good capture Chris. Looks like something is tilted in your new configuration that is producing the offband in the opposite corners. With a 2.6x GP you should be right in the centre of the sweetspot with no offband in the fov. Have you tried rotating the whole module in the focuser to find the most even fov? Interesting to know the 23.5cm distance.

[Rusted]

Good capture Chris. Looks like something is tilted in your new configuration that is producing the offband in the opposite corners. With a 2.6x GP you should be right in the centre of the sweetspot with no offband in the fov. Have you tried rotating the whole module in the focuser to find the most even fov? Interesting to know the 23.5cm distance.

Thank you all for your support under trying conditions.

Thanks Mark,

I have been chopping and changing my complete set up recently.
Now added a "real" focuser. Double checked the 200mm etalon/focus spacing.
Noted the focuser scale position for repeatability.
I tried using the primary focuser for improved sharpness but it is probably best left alone.

Alexandra mentioned rotating system components. Not something I have tried yet.
I notice two images when I peer into the Lunt B1200S2.
So it might well be worth rotating the BF, relative to the camera and to the etalon.
Just to check if anything changes. Rotating the etalon alone could also be profitable.
Still searching for a short helical focuser.
I've tried replacing the detached pin on my TS short helical without success.

My Baader 160mm D-ERF badly needs a bath but I am terrified of damaging it!
Any advice on cleaning off months of crud? My bulb blower and hair drier won't touch it.

After a sunny morning, with poor seeing, it is now totally overcast.
I'll report back when I've had chance to do some rotation trials.
Thanks again.

[marktownley]

I tried using the primary focuser for improved sharpness but it is probably best left alone.

Alexandra mentioned rotating system components. Not something I have tried yet.
I notice two images when I peer into the Lunt B1200S2.
So it might well be worth rotating the BF, relative to the camera and to the etalon.
Just to check if anything changes. Rotating the etalon alone could also be profitable.
Still searching for a short helical focuser.
I've tried replacing the detached pin on my TS short helical without success.

My Baader 160mm D-ERF badly needs a bath but I am terrified of damaging it!
Any advice on cleaning off months of crud? My bulb blower and hair drier won't touch it.

Categorically leave the primary focuser at the -200mm position - do not alter it!!! Ever!!!

The 2 images will likely be the blocking filter, rotating it should shift the ghost off the view. It could be the DERF, try rotating that, worth exploring if the blocking filter option doesn't shift it.

Rotating the whole assembly in the back of the primary focuser is the way forward. Find the best position for even illumination (use the 2.6x gpc) then make index marks on the assembly / focuser tube so you can ensure repeatability if you remove it again. I'm assuming you've checked the collimation of your new focuser using a cheshire eyepiece and adjusted accordingly to ensure it is orthogonal with the optical axis?

What does Baader recommend to clean the DERF? Personally i'd just wash it, but that may fill you with unease

Mark

[Rusted]

Categorically leave the primary focuser at the -200mm position - do not alter it!!! Ever!!!

The 2 images will likely be the blocking filter, rotating it should shift the ghost off the view. It could be the DERF, try rotating that, worth exploring if the blocking filter option doesn't shift it.

Rotating the whole assembly in the back of the primary focuser is the way forward. Find the best position for even illumination (use the 2.6x gpc) then make index marks on the assembly / focuser tube so you can ensure repeatability if you remove it again. I'm assuming you've checked the collimation of your new focuser using a cheshire eyepiece and adjusted accordingly to ensure it is orthogonal with the optical axis?

What does Baader recommend to clean the DERF? Personally i'd just wash it, but that may fill you with unease

Mark

Thanks Mark. All good stuff!

Re:The new focuser: I have a leveling base plate to play with.
No need for sunshine with the Cheshire.

I shall be experimenting endlessly once I get a bit more sun.

I still haven't found cleaning instructions for the Baader D-ERF online.
The original Baader paperwork has been "mislaid."

[Montana]

I always use 100% ethanol (well 99.8%) for cleaning lenses etc. Worked a treat on the TEC140 objective too.

Alexandra

[DeepSolar64]

I always use 100% ethanol (well 99.8%) for cleaning lenses etc. Worked a treat on the TEC140 objective too.

Alexandra

Would high proof moonshine work!? 191 proof Everclear?

[Rusted]

Thanks. Not sure whether I can obtain 100% ethanol legally.

I may just hold the D-ERF under running water and finish off with a rinse with distilled water.

The nearest we get to moonshine, in Denmark, is cross-border, cheap, German beer smuggling.

I seriously doubt that a bath in Danish lager would improve the front surface of my grubby D-ERF.

[DeepSolar64]

Thanks. Not sure whether I can obtain 100% ethanol legally.

I may just hold the D-ERF under running water and finish off with a rinse with distilled water.

The nearest we get to moonshine, in Denmark, is cross-border, cheap, German beer smuggling.

I seriously doubt that a bath in Danish lager would improve the front surface of my grubby D-ERF.

And the Germans make really good beer!!

[Alto]

Nothing wrong with that second one Rusted....

p.s. I find whisky good for dire seeing....

[MapleRidge]

Hi Geoff...

I'll drink to that statement...a nice single malt scotch to savour when you can

Brian

[Montana]

I use this for optics at work and of course millions of other things too https://www.fishersci.co.uk/shop/produc ... 2/10437341

But as you can see from the price at £262 I actually buy it for £8.74 (cancer research is tax free). Incredible how much duty and tax is on ethanol
Alexandra