Mars highs and lows

[Jarvo]

Hi all,

First real opportunity to use the new scope on Mars this week. I've gone and got myself one of those Celestron  9.25 XLT thingys specifically for the Mars opposition.

The past 48 hours have been quite a challenge as the first night was a complete wash out (There is a shot below to compare). 

It was interesting to compare the 2 evenings work. This first night I used the scope with a 2.5x Powermate and an IR cut filter and the results were disastrous (I actually thought the scope was defective). Last night I used a 2 x Apochromatic Barlow and no IR cut filter.

Both nights seeing were, in my opinion, broadly similar  that is to say not ideal. Mars was maybe 25-30 degrees high.

I can only conclude that the 2.5x Powermate was simply too much power on the first night coupled with some back luck with the air currents. Removing the IR Cut filter and getting a better result was surprising however, wondering if anyone has a view on this?

Focussing is an issue with the SCT therefore I've bought a Bahtimov Mask and will be treating myself to an autofocusser shortly.

Camera used was a QHYCCD QHY5III 290c Planetary Camera (lovely little piece of kit), a 2 minute .ser file using Sharpcap and 1500/2000 stacked in Registax, tweaked in Gimp 2.0.

So another learning curve (when will it end?) but encouraged by last nights results.

Thanks for looking.

Steve

 

[CraigT82]

Plenty of detail there in the first image. That's interesting about the improvements without the IR cut filter, I wonder if the QHY 290c has an IR cut window already installed in front of the sensor? 

[Jarvo]

43 minutes ago, CraigT82 said:

Plenty of detail there in the first image. That's interesting about the improvements without the IR cut filter, I wonder if the QHY 290c has an IR cut window already installed in front of the sensor? 

You're bang on the money Brown Dwarf. Just been looking at the online manual and there is an IR cut coating on the front cover:

"....The optic window is the IR cut coating or AR coating. So you need to be careful when cleaning it. You can also use the DSLR clean tools or the lens paper. Don’t use big force to clean it. The coating is not so hard and it is easy to get scratch when you use big force on it...."

[des anderson]

I`ve got an 9.25sct similar to you, and its coupled up to a Zwo 224 camera, and if I got results like your first image I`d be really proud. Des