New Year -- New Setup? (My ideas) :D

[Macavity]

As fellow "Solarites" know... We never get (stay) Rich!
But once I get an IDEA, there is "no rest" until I try it? lol

HA Setup:

The "Prime Mover" in all this will remain my cherished
Lunt50 Tha + B600 blocking filter (probably forever)!
However, of all the things that impressed me last year
were tentative experiments my ST120 Frankenscope!

The above, effectively a D=86mm; f/600mm; f/7 "Lunt"!

I get good [IMO!] "closeup" images, but the above setup
"weighs half a ton" and there's a big risk of the whole thing 
falling apart! I couldn't cope financially or "emotionally"! 

Aside: My MAIN purpose of using the (large) ST120 was to
allow me lots of "wiggle room"! I do not have a "workshop"
so had to make stuff like (90mm) ERF Cells & OTA "bungs"
using "Wood (MDF) Technology" and various hole saws!

Personally, I have always LOVED Startravel Achromats!
But I still *wonder* about things like spherical abberation
at HA wavelengths! ST scopes seems to be *optimised*
for GREEN light (I sense) rather than RED H-Alpha light?  

A quality 90-100mm (semi) APO at £1000 is too expensive
(for me!) + wasted on my "random" experiments! But I am
seriously thinking about buying a SW 80ED Evostar Pro...
(Everyone loves 'em, right? I lose D=86 --> 80mm but!)

Quote

My MAIN PLAN is Buy an ED80... Use proper adapters
to Lunt Etalon (get some stuff made "professionally"!)
Hopefully ending up D=80mm f=600mm HA scope!

CAMERAS!

There remains the THORNY issue of my Cameras! Despite 
some success with a trustly DMK41 I have issues of "spots"
on the Chip and would like to "totally forget about" FLATS,
Newton's Rings (on CMOS sensors) -- If I possibly can!  

I have the idea that the SONY ICX445 CCD chip may be
what I need? For UK, e.g. Celestron Skyris is expensive!
But I find that http://www.clearviewimaging.co.uk/ are
UK distributors for (now  FLIR?!) "Chamelion" cameras?

A toss up between the USB 2.0 and USB 3.0 versions?
My notebooks are only USB 2.0! But at £269 & £200
these Cams worth a "punt"? I hope they don't mind my 
revealing their prices (Get an account!!). Ironically the
USB 3.0 is cheaper(?) but I wonder re. compatabilty.

Anyway, "That be me". I congratulate anyone who has
read all (any) of the above! I welcome ANY IDEAS!  

[Lowjiber]

I not only read the whole post, I wanted even more.   The use of "Wood (MDF) Technology"  would (no pun) never have occurred to me.

Thanks much for sharing your new rig.  Hopefully, the Cloud Gods will grant you some decent sky soon.

Clear Skies

 

[Macavity]

My (New year / whatever) Best Wishes, back at you, L-J! 
Recalling some great ideas (adopted by me) from you...

"If we knew what we were doing, it would be Research"?

[Peter Drew]

I have doubts that downsizing from 120mm to 80mm despite the upgrade in glass type will give you a noticeable improvement. Ha seems to be a little more forgiving with basic optical aberrations. All of the similar mods I have made have been based on achromats but being a PST modder they have all been operating at F10. Optical figuring quality is still important for Ha.  

[Macavity]

Hi Pete, Thanks for your interest! A good point... But I also fear my(!)
lack of clarity? In truth this particular Frankenscope project was always
limited by funds for the Baader ERF, which is of course a 90mm one!

So it's not a 120mm HA scope, but stopped down to 86mm to give the
requisite f/7 for the Lunt50 Etalon! I probably improve the performance
of the F/5 (f=600mm) Skywatcher objective by doing this as well? <G>
So I would only be reducing the aperture from 86mm to 80mm...

But I take what you say on board! There may not be much gain in going
to the better glass... AND I don't doubt you have looked through a LOT
more Achromats than I have! lol. Also I note that the WISE(R) probably
modify f/10 solar scopes -- like PST's not my choice of an f/7 Lunt 50! 

The other "upgrade" possibility would be to use the 90mm ERF as a
sub-aperture one in the "middle" of a bigger/better (genuine!) F/7
Achromat. But then I would also need to go from a B600 to a B1200
blocking filter. As we know they cost almost the same as a new Lunt! 
(I may try that when "older and richer", but perhaps not just yet! lol)

FOR WHAT it's worth, I did try to get some impression of the quality
of a stopped-down (86mm) ST120 Achromat by looking at "White
light" images and comparing images using a standard H-Alpha (Red!)
narrow-band with Baader Continuum (Green) narrow-band filter. The
fiirst thing one notices is significant differences in contrast. The green
image is a lot easier to focus than the Red one! Of course there is a
possibility of different resolutions at different wavelengths! Ironically,
I was able to make the two images look a LOT more alike by a bit of
post-processing! So I would not say "for definite" that performance
of a Chinese Achromat is definitely inferior in (refocussed) RED light! 

YOU KNOW what it is like trying to make "precision comparisons" of
systems in the UK. You start out with a nice Sunny Day and an hour
later the Clouds start to appear!  None of this is "Gospel" anyway!

As ever I thank SGL'ers for providing a great (erudite!) sounding
board for my "wacky ideas and random experiments" etc. etc. 
If this ever makes any real sense, I may "publish", as they say! lol

[DrRobin]

I used a DMK41 and then bought an ASI120MM, there was some Newton Rings.  Finally once an ASI174MM was bought there was none.  With a Barlow my DMK41 would show some NR patterns, but the ASI174MM is perfect, so if funds will stretch....  Firecapture is very good at applying flats in real time and gets rid of all of my NR issues.  A blower brush sorts out dust.  Actually that is another plus point for the ASI, they have an optical window, meaning dust is easier to deal with, unlike the DMK series, which I had to get clean and then fit an IR filter to prevent dust.

However, for my Lunt 60 DS, the pixel size on the ASI174MM is just too large and an ASI120MM is a better match.  My DKM41 is now consigned to be a guide scope camera on my night time rig, seems a bit of a waste, but it does give a nice field of view and seeing as my QHY5 doesn't seem to want to adjust any longer, some sort of driver issue, it was a quick fix.

As much as I like my Lunt 60 DS and I do very much it hardly gets used anymore, I prefer a Quark to allow for a larger aperture scope using with a WO Zenithstar 80mm (on holiday and at home) and a GT102 when I can be bothered to get two cases out of the study.

Best of luck whatever you end up with Chris and Happy New Year to all.

Robin

[Merlin66]

Robin,

My experience is different...

I use a ED80 + SM60 and a TS102 PST Mod as well as a Omega CaK filter stack.

I used the DMK41 and DMK51 for many years with no NR but recently "upgraded" to the ASI 174MM ( primarily for the fast frame rates needed on the spectroheliograph) and immediately ran into NR issues (worse when using the x2.5 Powermate). The answer was to fit a T2 tilter. NR gone!!!

(Note: the DMK51 doesn't play well with usb3 - frame rates halved.)

 

 

[DrRobin]

Merlin, that is strange, perhaps it has more to do with the interactions of the coatings of the various optical components/combinations than a specific model?

I confirm that if I use an ASI 120MM on. Lunt60, especially with a Barlow I see Newton Ring patterns.  If I use a DMK41 I only see these with a Barlow.  However, my ASI174 doesn't show any Newton Rings on my Lunt with or without a Barlow.  Neither does it show any Newton Rings on my Quark, which does show them very extensively with a ASI120MM and to a slightly lesser extent my DMK41.

I tried a tilt corrector on an ASI120MM and found that I had to introduce so much tilt, it leaked light (sorted out with some thick black tape) and one side was slightly out of focus, no easy solution, so went back to flats, using Firecapture.  Actually the field on my Quark is very uneven, I liken it to clouds, as that is what it looks like, but the contrast and detail is good, so put up with it and take flats every time.  

I still have the tilt corrector and gave it another try, but still couldn't get it to work without other problems like focus so consigned it to the good idea but didn't work for me bin.  I know I still have it, but not sure where it is now.

[Macavity]

Thanks for all the above interest/info! It can seem like there is not a lot of
consistency in individual experiences? For the moment, I think I will try the
USB2.0 Chamelion 1/3" with 3.75 micron pixels (assuming I can get one!)

I sense I was "unlucky" (though I know not unique!) in getting a DMK41
with some "slightly dodgy" (less responsive) pixels. And, as with many a
"scientific / artificial vision" Camera manufacturer they will "never quite"
understand the *extraordinary* requirements of Solar H-Alpha imaging.

FWIW, I did try tilting the ASI120MM but never felt "completely happy".
I have already spent quite a LOT of time "clocking" my Lunt 50 to get a
central and even "sweet spot" (or whatever)! Plus I am a bit "OCD" re.
introducing an obvious dog-leg into the optical path (That's just me)?  

I don't think I will make any dramatic changes re. Frankenscopes THIS
month. I know to my COST(!) the folly of changing many things at once?
It's quite a "war of attrition" to optimise a *personal* H-Alpha setup... 

[Macavity]

Enthusing re. "budget" ex-VAT Chamelion Cam price...
but forgot 20% VAT "shocker". Please ignore me! lol 

[DrRobin]

I tried to avoid flats, doing the same as you clocking my Lunt 60 and double stack to find the sweet spot,even then I had to restrict the chip area on a ASI174 to something nearly square.  Once I started using a Quark and after getting one that worked correctly I had to use flats but they are very easy in firecapture.

Just centre your scope and defocus until the Ha features blur to an even field.  Then set the peak magnitude to 70% and take a flat.  Once taken the flat is subtracted in real time.  I notice I have to set slightly longer exposures and on the screen there looks to be slightly less contrast, but a good flat lets you push the contrast in post processing so you easily get back what you loose.

if you change resolution or anything on your scope you need to redo the flat, otherwise gain, exposure and gamma are all okay to adjust.

Given the amount of activity, I think I would stick with the cameras you have and give flats a really good try, there isn't much to image at the moment.  Then perhaps get a new camera after the solar minimum.  There might also be a few coming up second hand, there isn't much solar and most of the planets are going to be low for the next year or so.

Robin

[Pete Presland]

I also do the flats in Firecapture and it works very well. I can not see me moving away from my DMK until the NR is resolved as also do not like the idea of introducing an obvious dog-leg into the optical path. I do wish I had better frame rates for my mosaics though. 

[Peter Drew]

"War of attrition to optimise a personal Ha solar setup" (Macavity)

It's taken me 10 years for me to reach my personal solar "Nirvana", a 150mm aperture, high resolution performance instrument that I can comfortably use with binoviewers. It's probably the end of the road for my own quest as I have no need for anything better, all experimentation now is focused on improvements I might be able to achieve making such things for others. 

[Macavity]

Heheh - Pete and ALL! Whatever... I have *rashly* "pushed the button" on the
Chameleon 1280x960 1/3" USB2 Camera -- And even got a REPLY from the UK
distributor! In the near / far future, I may add another "point on the graph"? 

Not in the "First bloom of youth", I cannot help but notice we are approaching a
Solar Minimum! Since I gained a modicum of practical expertise I cannot help but
note that the planets too seem to be hiding in the nether parts of the Zodiac! 

I suppose the moral of the story: Don't *procrastinate* doing the REAL stuff? 

[DrRobin]

I think like Peter, I have reached my final solar set up,

Lunt 60 double stack with ASI120MM;

William Optics GT102 with a Quark/Lunt CaK and ASI174 for use at home; and

William Optics Zenithstar 80mm with a Quark/Lunt CaK and ASI174 for travelling/taking to work.

I am of the opinion that the Zenithstar 80mm I bought second hand is the best little telescope I have ever owned and possible the best I have.  Therefore for solar I don't really want for anything else.  

However, Chris I fully understand your reasons for pushing the button on new kit, you might as well enjoy your hobby whilst you can, I am the same, don't bother waiting for tomorrow and just think how expert you will be when the next solar max comes along.

Robin

[Macavity]

On 1/4/2018 at 13:26, Macavity said:

Heheh - Pete and ALL! Whatever... I have *rashly* "pushed the button" on the
Chameleon 1280x960 1/3" USB2 Camera -- And even got a REPLY from the UK
distributor! In the near / far future, I may add another "point on the graph"?

I doubt anyone was literally hanging on the above, but it seems like the particular
favour of Chamelion Cam (USB2!) has an earliest date for delivery, END of April. I
decide the money was "better off" residing in my Bank account. But the UK agents
for Point Gray / FLIR: clearviewimaging.co.uk have been helpful/rapid in response. 

Not sure WHERE I am going with this project now. Was thinking about the Skyris
445 Camera (also based on Sony ICX445 CCD) but then worried about the various
issues of USB3/2 compatibility; lack of Gamma adjustment, (effective) ROI etc.   

Back to becoming "the next Jimi Hendrix" (whatever) after all? 

[Macavity]

Hold the front page! As I looked wistfully through pages of "awaiting delivery"
for (any) Point Grey / FLIR Cameras, I casually turned over  to the UK page of:
https://www.edmundoptics.com/
Suddenly: A USB3.0 Mono 1288x964 3.75 micron one in the Yorkshire branch!

So, I am now the proud (but poorer!) owner of the aforesaid! It only left their
Canada factory TEN days ago. So they are still in production (for information).

It is only my Desktop machine that has USB 3.0... under Win7! So I tried out
the (slightly cryptic) installation and it ALL works! Could it *possibly* work on
the 2002 version Win XP (SP3) on my "data acquistition" notebooks? After an
quick upgrade to .NET 4.0 and update to Windows Installer... It DOES!  Yay!!

Surprisingly, I get 30fps (960x960) even under USB2 (More at reduced ROI?)!
Of course the REAL test for me is image quality... Newton's Rings specifically...
But there is hope now! All I need (as ever) is for the SUN to come out finally.