Mars 27th Jan

[Sebbie (Sebastian)]

I got blessed with a brief period of very good seeing around 4:55 this morning, after that conditions deteriorated quickly.

Did not have to do much processing on this one as the scope seemed to have achieved ambient temperature well (no severe edge rind this time round).

I've also eased on wavelet sharpening which makes the image look more natural.

Rgds,
Sebastian

[Astro_Bot]

That's a nice one, Sebbie.

With these martian pics popping up daily, one could just about say, "A Mars a day helps you work rest and play".

[Maurice]

Excellent image Sebastian...well done.

'Seeing' is always the 'make or break' part of the imaging equation that we can't control
How do you cool your scope for imaging?

Regards
Maurice

[Sebbie (Sebastian)]

Thanks guys.

Originally Posted by Astro_Bot

"A Mars a day helps you work rest and play".

He he certainly helps you get up early and play Astro_Bot. Not sure about work and rest aspect of it... turning up to the office blurry eyed day after day can become a drag

Originally Posted by Maurice

How do you cool your scope for imaging?

I don't have a cooling system attached to the LX but would like to have one installed. Bit apprehensive about drilling holes into the OTA in order to mount a small fan though.. is there any other options? I usually leave the scope parked outside at least 9 hours before imaging under the cover of a blanket / fitted sheet.

Rgds,
Sebastian

[Astro_Bot]

Originally Posted by Sebbie

I don't have a cooling system attached to the LX but would like to have one installed. Bit apprehensive about drilling holes into the OTA in order to mount a small fan though.. is there any other options?

To cool without cutting/drilling any holes you could use a Lymax style cooler that sucks air through the rear baffle.

Here's the brand-name version:
Lymax SCT Cooler for 12" Meade
Paul Haese wrote a review of the Lymax in 2006:
Lymax SCT Cooler review
... and there's some discussion of SCT cooling here:
SCT Cooler discussion
Interestingly, Paul went on to use peltier cooling with holes cut through the rear of the OTA when he up-sized his OTA, or at least I think so, if I read correctly - you could ask him directly, I suppose.

There's a DIY version of a Lymax cooler that you could make:
DIY SCT Cooler

I saw someone had a flexible tube from a vacuum cleaner with a computer fan on the end of it to cool their OTA, albeit I think it was a reflector. Still, you could also try that.

I have a Meade 10" ACF that seems to cool adequately in about 2 hours (or less) under a clear sky, but then I'm not yet attempting the feats of astrophotography that you are! I have some reservations about blowing outside air through the middle of my OTA. If I were going to do that, I would really rather blow filtered/de-humidified air, to reduce the risk of mould or fungus spores getting a toehold.

[U.K.Cowboy (Stuart)]

Lovely image! Look forward to seeing your Mars captures around opposition, by the looks of this early effort they are going to be pretty special!

[John Hothersall]

Good detail, can't wait to have a go myself.

John.

[John K]

Very nice Seb!

[Sebbie (Sebastian)]

Originally Posted by Astro_Bot

To cool without cutting/drilling any holes you could use a Lymax style cooler that sucks air through the rear baffle..
I have some reservations about blowing outside air through the middle of my OTA. If I were going to do that, I would really rather blow filtered/de-humidified air, to reduce the risk of mould or fungus spores getting a toehold.

Thanks Astro_Bot. Had a look at the CosmicOne specs, interesting.. Quote: "The SCT Cooler has a filtered air intake and other design features which minimize the possibility of dust infiltration and direct the air flow away from the internal optical surfaces.. (it) draws outside air in through a high capacity fan."

Like you I am a bit uneasy about contaminating the inside of the tube in case of filter breakage.. sucking in pollen or small bugs is a bit of a worry at my location as I am surrounded by bottlebrushes and close to a local pond.. Will do more research re recommended maintenance cycle later.

Originally Posted by U.K.Cowboy

Look forward to seeing your Mars captures around opposition, by the looks of this early effort they are going to be pretty special!

Thanks Stuart, I still have my L plates well and truly on.

It's good to be able to benchmark one's effort against expert planetary photographers on this forum such as Stefan, Asimov, Quark and yourself! (to name a few).

Originally Posted by John Hothersall

Good detail, can't wait to have a go myself.

Originally Posted by John K

Very nice Seb!

Thanks guys, I'm beginning to understand why Mars holds a special place in the history of visual astronomy. The only other rocky planet with seasonal changes and Earth like polar regions.. very addictive to track and observe over time

[Astro_Bot]

Originally Posted by Sebbie

Quote: "The SCT Cooler has a filtered air intake and other design features which minimize the possibility of dust infiltration and direct the air flow away from the internal optical surfaces.. (it) draws outside air in through a high capacity fan."

Well, there's filtered and then there's filtered.

I've done some work in the middle east where ultra-fine red sand (so fine it can stay airborne for days in a true "sand storm") got right through some pretty good filtering systems and into electronic equipment enclosures. It also got through rotating joints into mechanical systems that were supposed to be weather proof! The sand was allegedly in the 1-10 micron range and I figure enough of it was close to 1 micron to get through the fine filters.

Typically, mold spores are in the 2 - 30 micron range (so I read - although opinions vary somewhat). I think I would want a ~1 micron filter (and a fan powerful enough to suck air through such a filter) before blowing it through my OTA. Basically, any true HEPA filter ought to do the trick.

Like you I am a bit uneasy about contaminating the inside of the tube in case of filter breakage.. sucking in pollen or small bugs is a bit of a worry at my location as I am surrounded by bottlebrushes and close to a local pond.. Will do more research re recommended maintenance cycle later.

Inadequate filtering would be more of a worry rather than filter breakage, at least IMHO. Most mold spores are released at night - around midnight to 2am - right when we're observing! In contrast, most pollen is released during the day.

Out in a field with your telescope would be perfect for catching those pesky mold spores, so, for me, good filtering is very important. Until then, my OTA stays as closed as possible.

[Quark (Trevor)]

Impressive effort Sebastian, nice job with your processing also.

Regards
Trevor

[Sebbie (Sebastian)]

Interesting observations Astro_Bot.

My corrector plate is already covered by fine layer of pollen and I've only had the scope out less than 20 times I'd say.

Blame it on springs in the bush capital

Originally Posted by Quark

Impressive effort Sebastian, nice job with your processing also.

Thanks for appreciation Trevor, I am definitely motivated for this opposition now

[Astro_Bot]

Pollen released during the day can stay airborne for hours on the wind, i.e. well into the night. I spent a decade living in Canberra with hay fever and know it only too well.

Whereas you can see most pollens, being much larger, you won't see the mold spores. Any filteration effective against mold spores will be even more effective against pollen. And whereas a viable mold spore can grow into mold (if it finds suitable conditions), pollen will never grow into a plant.