Mars and Jupiter from Melbourne 6th Jan UT

[MarkJ]

Hi all,

I imaged Mars and Jupiter in good seeing last Thursday morning.

Previously I had captured at 30 FPS with an EFL of about 11m but this time I shortened the EFL down to about 9.6m and ran at 60 FPS. I think the higher frame rate was worth it although it is always hard to tell. My DMK21AU618 camera has relatively large pixels at 5.6um so I probably shouldn't reduce the focal length anymore.

I stacked about 20% or 30% of the 3600 frames captured.

I run a cooling fan which stays on when capturing. It is supported by a rubber band (slice of a car inner tube) and I cannot see any signs of vibration.

Mars image from 6th-Jan-16 18:45UT
Jupiter image from 6th-Jan-16 18:27UT

Best regards,
Mark

[Cimitar (Evan)]

Wow! Very impressive . The detail on Jupiter is amazing

Am I reading that correctly when it says you're effective focal length is 9.6m? How do you achieve that, are you using a Powermate?

Cheers, Evan

[Quark (Trevor)]

Really nice images there Mark, very well done.

Cheers
Trevor

[ags_ (Phil)]

Excellent images Mark, I'm interested in the gear you used to achieve these.
Regards, Phil

[rustigsmed (Russell)]

wow they are really well done Mark, nice work!

[MarkJ]

Originally Posted by Cimitar

Wow! Very impressive . The detail on Jupiter is amazing

Am I reading that correctly when it says you're effective focal length is 9.6m? How do you achieve that, are you using a Powermate?

Cheers, Evan

Thanks Evan, Glad you like the images.

I use a x5 Powermate and the x5 is different than the other Powermates in that you can increase its power by moving the camera's image plane back from the top edge of the Powermate. See the TeleVue chart at:

http://www.televue.com/engine/TV3b_p...agCharthttp://

I have the camera sensor about 55mm back from the top edge of the x5 Powermate so from the graph this gives a magnification of about x6.5. My scope's focal length is 1.5m and with the Powermate at 6.5x I get an effective focal length of about 9.75m.

I hope this helps.
Mark

Originally Posted by Quark

Really nice images there Mark, very well done.

Cheers
Trevor

Thanks Trevor, Comment appreciated.
Mark

Originally Posted by ags_

Excellent images Mark, I'm interested in the gear you used to achieve these.
Regards, Phil

Thanks Phil,

My equipment is:

12" F5 Bintel Dob repurposed onto a Losmandy G11 for planetary. Mirror, secondary and focuser are stock however the mirror support has been reworked a little to more gently hold the mirror. It really is a crap mirror cell. Also, the springs have been turfed and I now rely on the push/pull screws to lock the mirror in place.

I use the original fan but now have it supported by a rubber band as previously mentioned. I use the scope in open air in my backyard and set the fan running as soon as the scope is set up some hours before observing. I have lined the inside of the tube with foam sheet a bit like how the old timers used to line their tubes with cork. Not sure if this does anything but I'm sticking to it.

Camera is a DKM21AU618. Filters are Edmund RGB and I run an Astronomic IR block. I use a TeleVue x5 PowerMate. I use an Orion manual five position filter wheel. I run an Orion motorised focuser controlled by a Shoestring FCUSB. I would like a motorised filter wheel as the 12" is really a bit much for the G11 and I need to be very careful when manually changing the filter.

I hope this is of some interest.
Happy to answer any other questions as best as I can.
Mark

Originally Posted by rustigsmed

wow they are really well done Mark, nice work!

Thanks Russel for your kind comments.
Mark

[John K]

Great work Mark - looks like the morning of the 7th was indeed great for seeing in Melbourne!

[Maurice]

Lovely images Mark.
Incredible Mars at 6"!

cheers
Maurice

[Rod771 (Rod)]

Very impressive results, Mark! Excellent detail.

[ags_ (Phil)]

Thanks Mark for the equipment update, I'm using a TV 5x as well now with binning to reduce the image size, they are excellent quality and low weight. You are doing very well indeed with a modest mirror. Seeing is 95%.
Regards, Phil

[bigjoe (JOSEPH)]

Great work Mark and nice tip with the 5x powermate!

What a focal length!!; these 12" gso's can be great -just those useless springs you would have thought they would have changed to something better by now.

Mars at 6" excellent!!

bigjoe.

[andyc (Andy)]

Both excellent images, thanks for sharing them