solar mono cam

[xtreemchaos]

hi everybody, I need to pick your brains, I need a mono ccd to use with my Quark and ed80, 120mm f5 frac and AR127l f9.5 frac, it needs to be no morethan £200 " if I want to stand a chance at getting a tak for crimbo" and one what would give me the largest image possible, at the moment I'm using a asi120mc and when converting to mono its giving me lines and blocking.

if you look closely at this image you will see what I mean, ive posted this in the imaging sec because I think I could get more help here. thanks charl.

[Craney]

All things said about finer details,  it is still a spectacular image.  Those plumes between the spots have structure within them. Marvellous.

[xtreemchaos]

thanks Craney, I have added contrast boost to show the lines better, didn't notice until you said, yer mate the lines ant too bad but the image would be better without any ,deeper processing is impossible for me as it just brings more lines to the party.  clear skys mate, charl.

[johnfosteruk]

What about the ASI120mm Charl, you know the image scale and weight etc, assuming the issue is just because of the bayer matrix or some other quirk of the colour camera it'd fix your problem I'd bet.

[xtreemchaos]

thanks John, yer I have thought about the asi120mm but would like to get a larger image if possible, with me shooting from indoors the high mag I get with the Quarks built in barlow is a bit too much, I do use a 50% reducer to lessern the mag but id like to do without it as the less glass the better mate.  charl.

[johnfosteruk]

Then

9 minutes ago, xtreemchaos said:

the less glass the better mate.  charl.

Then I'll leave my 2 penneth at that mate and wait for someone else to share some wisdom

 

[michael.h.f.wilkinson]

It seems you need something with bigger pixels. There is the ASI174MM, but that is well beyond your budget. The ALccd-QHY 5- II has larger pixels too, and is within budget, but my experience with the ASI-130MM, which has the same chip, suggests it has a lot of pattern noise and requires darks and flats to correct for this.

[xtreemchaos]

thanks Michael, the QHY 5-2 looks quite like it fits the bill, I have the colour ver what I use for guiding wonder if its the same chip size if it is it would give me a look at the field of view, I will look into this . thanks for the link. charl.

[michael.h.f.wilkinson]

 

18 minutes ago, xtreemchaos said:

thanks Michael, the QHY 5-2 looks quite like it fits the bill, I have the colour ver what I use for guiding wonder if its the same chip size if it is it would give me a look at the field of view, I will look into this . thanks for the link. charl.

Personally, I would prefer the ASI120MM with reducer. The MT9M001 chip really has a lot of issues, which can be tamed with processing, but they are a pain. This is one of my better results with the ASI130MM and LS35THa. Not bad, perhaps, but still quite a lot of issues. I will try to dig out the raw files to show the issues in more detail

[xtreemchaos]

thanks Michael, I see what you mean mate, ive just been comparing chips in the 120mc and QHY5V what I own and the 120mc looks the bigger or the same or is there more to it than just compairing by eye heres a pic .

I'm tempted to sell a few bits and go for a cam what I can use for Deepsky work too, ive quite a while to think about it as wont beable the buy until the end of april, something 2/hand may pop up soon too, just doing the intel on which cam would be best..

[David Smith]

I use the QHY5-II Mono but do get newton rings when used with the PST for H Alpha. It seems to work reasonably well with the Evostar 120 which is similar in focal length to your AR127L. Not having a Quark though I cannot give you a direct comparison. One of these days I will upgrade to something like the ASI178 but for now the QHY will have to do.

[Merlin66]

I used the DMK 41/DMK51 for many years, but the low frame rates caused me grief when considering the spectroheliograph application.

I ended up "investing"(!!) in a new super fast computer with SSD drive and USB3 and the ASI 174MM. Seems to be capable of working at >400 fps with the SHG.

When used on the SM60 or the PST mod there are definitely newton ring issues with this camera. I've just ordered a Tilter adaptor to put them to bed.

Charl,

I'm sure you don't have to pull your cameras apart to verify the chip dimensions - all the data/ dimensions are readily available from the suppliers.

Use CCDCalc to verify the FOV and plate scale.

http://www.newastro.com/book_new/camera_app.html

[Macavity]

As a similar questioner on CN put it... "It's all a bit of a "Cr*p Shoot" isn't it"?  
Having recently conducted an exhaustive (exhausting!) "Google survey" I agree!
I found that the ASI 120MC (colour) is a fine (enough) thing... But, as you say,
we are only using 1/4 of the Pixels - RED ones, losing Sensitivity & Resolution?

I also bought an ASI 120MM and can *certainly* vouch for the fact it produces
Newton's Rings. LOL. You CAN indeed "Drift" them away... but (for me!) that is 
level of complexity to remember. (Insert semi-random numbers into Eqmod!).
With a periodic pattern, you need a significant drift, which may / may not get
rid of it? More importantly, with a Lunt 50Tha, I find there is a quite particular
position on a chip where the "sweet spot" is optimum? Plus I get fed up with
"rescuing" the Sun as it drifts out of field between exposures! 

Not overly enthuised by the idea of *Tilting* either. It just doesn't look right!
And I see SOME folk assert that "no matter how much you tilt" an ASI120 MM 
it  still wont rid you of Newton's Rings! Other chips may be more amenable?

I have just spent £500 on my presumed "Nirvana" (for Solar H-alpha anyway!)
the DMK41. The larger chip is great... I can cope with slower speed (USB 2.0). 
But whether I should be happy with visible "blackspot" on the chip is moot!  

Flats appear to work, but again add a layer of complexity to the whole thing.
I have yet to explore the possibility of *returning* the thing or "making do"!
To my mind anyway this is a "hardware problem" and arguably shouldn't be.

As a random speculation, I AM guided by the notion the "CCD" chips are far 
less likely to give Newton's Rings than CMOS! That, seems *mostly* true??? 
Imaging Source (as with many "Industrial" suppliers) have moved to CMOS.
I DO casually wonder whether buying a *designated* "Astronomy Camera"
increases buyer-confidence? Newer IS/Celestron Skyris are USB3.0 & "CCD"? 

But £400-700? I note your budget restrictions. On many levels, I empathise!

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