Getting back into astro after an 8 year hiatus... advice on gear developments etc

[Robert_T]

Hi all, I used to be a regular around here and have been in an out of Astronomy since I was a teenager in the 70's/early 80's... my last real Astro-post here though was in 2008 when I drifted away into photography more as a hobby and have been pursuing that ever since and haven't touched a scope in 8 years despite a lot of equipment lying around the house and in cupboards etc.

I have a whole bunch of questions I'm hoping you good folk could help out with.

For background, my main (almost sole) interest in Astro back in 2008 and years leading up was in planetary imaging using a C9.25 and a range of webcams the last of which I think is in my signature here... I used RGB filter wheels, temperature equalising wand thing, dew zapping hood etc (all of which I still have), and registax etc and managed to squeeze a fair bit of detail from that kit on Jupiter, Mars and Saturn... but reckon I've killed off all the brain cells that led to that.

Anyway, I just took the cap of the C9.25 and found some lovely coin sized patches of fungus growing on the corrector plate. I recall a few years back flooding upstairs actually leaked water into the tube and had to be drained out...so expect it's inside...the mirror by contrast looks pretty pristene... I'm wondering if it's salvageable... ?I don't feel like trying to clean the corrector myself (really had my time doing that stuff)... is there anyone in Australia that offers a professional cleaning service?

Has there been any changes in recent years on the best scopes for planetary imaging? I did have a Mewlon 210 at one point but found I got better from the C9.25... always a trade off between aperture and seeing... Ideally I'd prefer something more like the Mewlon config...compact but with long FL and no corrector plate for quicker tube cooling...then again I'm probably thinking with a 2008 mindset and have no idea if anything better has come along...? I'm all ears.

What about mounts? I have an EQ5 on a star spanner pier and an LX5 meade computerised mount on a heavy tripod...I never got the hang of this mount ... I was never happy with either and would like something a bit more refined.

On cameras what is the "go to" for planetary these days? and is registax still the software of choice? I have a range of Mirrorless Camera, Olympus EM1, EM5ii and the Sony A7rii, but expect their larger sensors would be wasted on planetary? Is the best approach still combining separate Red Green and Blue monochrome images or have colour cameras come along enough to get away from all that fuss?

Maybe there's a scope type (5-6in refractor?) that would suit both planetary and suburban deep sky stacking stuff and my mirrorless cameras could be put to deep sky purposes via multiple short exposure stacking to avoid light pollution impacts.... almost starting to remember stuff long since forgotten here.

Anyway, thanks for sticking with this ramble so far, and if you have any advice or suggestions I would love to hear them.

thanks,

Rob

[rustigsmed]

hi rob,

welcome back to the hobby.
the sony sensors are super clean. not too much else has changed i would suggest. the new skywatcher AZeq6 might be worth a look.

there are some good cooled planetary cams now check out the zwo range http://astronomy-imaging-camera.com/ even the 120mm is capable of superb results.

planetary software programs: registax 6, PIPP, autostakkert are probably the main ones as well as winjupos for planet derotation.

can't think of too much else at the moment, not sure on the funghi cleaning i'm afraid! maybe get some sunlight on it (remembering to remove any eyepieces). how about a 10" carbon fibre newt with a quality 5x powermate for a scope?

cheers

russ

[Robert_T]

thanks russ, appreciate the reply... the 120mm kit looks good and i will check outthe mount as well. i think my days with newtonians are over... in my early days i ground mirrors and made an F7 12inch... a purpose built observatory to house it and massive home made mount. these days the c9.25 would be about as big as i want as id be wrestling it out each time i wanted to use it. i might even fall back to a 4in ed refractor to start. i would like to get the fungus in thec9.25 sorted either way.. whether to use or sell. cheers rob

[Camelopardalis]

Rob, I've never done it myself but removing the corrector is supposed to be fairly easy, so long as you mark the position relative to the OTA and keep track of the spacer cork when taking apart. Failing that, give Bintel a call, I'm pretty sure they do SCT servicing.

The 120mm is a decent mono cam but the 174/185/224 are a step ahead now, but it's changing every year. There are some new sensors like the 290 out now that I've not heard any reports out but they have interesting specs.

The new cams can capture at pretty high frame rates. Can't imagine that with one of the new cams, your cleaned C9.25 and a night of decent seeing that you wouldn't get good results..

[raymo]

Dunk is right, it is easy. just as Dunk said, but additionally, just in case any cork spacers should fall off when removing the corrector, it is a good idea
to grab some feeler gauges and measure the gap top and bottom, left and right, before hand.
raymo

[Robert_T]

thanks dunk and raymo, its not so much the taking the plate off that worries me its how to clean off fungus without making an even bigger mess and how to stop it regrowing.... also not sure if the fungus would have stripped off the coatings...any ideas on how to deal with the fungus aspect? thanks for your help

[Camelopardalis]

Doubt it's done any damage IMO, just be careful, handle it like your finest china :) I clean my corrector with isopropyl alcohol (you can buy it in the chemists), not only is it a good solvent but it'll kill pretty much anything. IPA won't damage glass/metal/plastic unlike some other solvents. Start at the centre and wipe towards the edge and you should be fine, fungus and smear free!

[Robert_T]

thanks Dunk. I'll work myself up to give it a go. I think in the past when I've done this sort of thing I end with a liberal dousing with distilled water after the IPA clean?

[Camelopardalis]

Sounds like a good plan. With distilled water if you get any watermarks or staining, it's very unlikely to have any effect on image quality.

[Robert_T]

well I cleaned the corrector. read up a bit and found original formula "windex" to be one of the best things for dissolving fungus and killing spores. after marking location of the corrector and removing I dabbed windex on make-up pads onto the fungus and it dissolved it almost immediately. followed up with IPA and distilled water. All looks good as new now :-) Not sure when I'll get a chance to use it...need to re-learn how to collimate too!

[Camelopardalis]

Nice one Robert! Collimating might be the harder part ;)