So first PST Image - need help

[johnb]

Hi

So i have my Coronado PST with a DMK 41 mono and a short nose piece, and im using IC Capture.as.2.2

So I'm able to focus but it seems washed out gain is 0 as is brightness, exposure is around 1/70

Fiirst image is attached, pointers really appreciated.

Regards

John B

[riklaunim]

Gamma/brightness should be left unchanged. The exposure should be very short + lowest gain and it will work. You should be able to go shorter than 1/70.

[David JM]

First off, are you sure you have achieved focus? Most CCDs/webcams have a lot shorter focal length than the eyepiece that is used, I focus on the limb first, then move onto the sunspots that are my usual target.

Assuming the focus is accurate have you tried the software in full auto? This may help a bit initially, then you can fine tune. With white light and a solar filter I can use as low as 1/2000 with half gain and half brightness with a NexImage and a 4SE. Trial and error may be the key.

[hunterknox]

As above - drop the exposure first. Also, a clothes peg on the focuser knob makes focusing much, much easier.

[johnb]

Thanks for the info. When I bought the kit I did get a short nose piece as advised so im sure I can achieve focus. I will try the exposure as suggested and see what happens.

Thanks

John B

[johnb]

Hmm becoming a pain, I have attached a screen shot in live image view with the settings help appreciated.

Regards

John B

[riklaunim]

Lower the exposure time and that's all to get a good image (+ focus)

[johnb]

im think its a focus issue, i have a short nose piece and even tried with out a nose piece but still nothing help ?, what would you imagine the exposure time should be ?

[Photosbykev]

With the dmk41, gain @ 260 and gamma @ 100 i.e. defaults. From memory prominence exposure will be around 1/15-1/30 and surface detail 1/200-1/320. Get the focus sharp on the edge first then tune the etalon to bring up the detail

[johnb]

Thanks for this, it was focus, I have unscrewed the lens from a 2 x barlow and then dropped it in the eye piece then inserted the DKM with a short nose piece and now I can focus.

I do have another issue. when really out of focus there are strange dots see the picture,

regards

John B

[Photosbykev]

I can't see the image on my phone but it is very likely to be dust bunnies on the sensor

[SteveT]

Yep, dreaded dust on the sensor.

Sent from my iPad

[johnb]

thanks - finished image is here - http://stargazerslounge.com/topic/152715-first-solar-image/ quite happy with it really.

Regards

John B