PST pics 28.08.08

[frogbmth]

Just some shots through my PST today using the DMK21 monochrome CCD. First two are using no barlow, just a low profile C-Mount. Second two are with a 1.6x magni-max

Andy

[robindurant]

Hi Andy

I have just purchase a PST and want to image with the same CCD as you. Can you help me with details of your timing and settings and possibly your method. I am sure others will like to know how you produced such great images.

Robin

[frogbmth]

Hi Robin

I am using the IC Capture application included in the DMK package, with the following settings

Device>Settings

Video Format Y800 (640x480)

Frame Rate 30.00003 FPS

Device > Properties (remove auto on these)

Brightness 19

Gain 273

Exposure 1/54 sec (to start with)

Gamma 89

Recording Settings

Container type AVI

Video compressor Uncompressed Y800

View > Toolbars

Enable Recording toolbar

Enable Exposure bar

I then find focus on the PST and adjust the exposure to suit the conditions in the toolbar. Higher for proms and lower for surface detail.

The C-Mount supplied with the DMK will not allow you to reach focus on the PST without using a barlow, but if you swap it for a low profile version from modern astronomy it reaches focus without a problem without any barlow. I place the camera in the eyepiece holder with the tripod mounting block facing up the telescope tube towards the objective. This way the disc appears on my laptop screen in the same orientation as in an eyepiece. I get so easily confused otherwise!

The laptop I use is an Asus eeePC with Windows XP installed and I save the files straight to a 4gb SDHC card. I have the processor overclocked for better frame rates from the camera. I house this in a 16" square popup black photographic tent so I can see the screen in the bright sunlight. I can do a pic if it helps.

Once I have the video files, I stack them in registax with some saved scheme presets (I can list these if you want them) and save the file to postprocess in Paint Shop Pro PhotoX2. I have some scripts saved in PSP for colourising etc. and again I can share these if you like.

I'm still very new to all this but I think I am going in the right direction. They will certainly get you started. The DMK is a great camera, I am delighted with mine.

Andy

[algol]

great those, all of these PST pics are a great advertisement for the scope.

[robindurant]

Many thanks Andy

[robindurant]

Another question Andy. Where did you get your pop up photographic tent. I can't find any on the net.

Robin

[frogbmth]

Hi Robin

I have sent you a link by PM. The little tent is manufactured by Lencarta Photo and comes in a pouch that it folds into, an 8" disc. Very handy!

Regards

Andy

[beamer3.6m]

Can I ask a stupid question.

Does the view through a PST look like your images or is it the same as the DSO images not being a true representation of the 'fuzzies' you see in the eyepiece.

If it actually looks like through the PST then the view must be stunning.

[frogbmth]

It's not a stupid question at all.

The view through any Ha scope is monochromatic red. This is because only one wavelength passes through the filter, these images have been coloured to taste. The real live view is more like this image, but more magnification brings out the prom detail quite nicely.

Andy

[beamer3.6m]

I prefer the image colour than the observing colour but still very impressive.

[frogbmth]

I agree, to be honest it is very hard to represent the eyepiece view in an image and that pic doesnt do it justice. It's awe inspiring and a world apart from the fuzzy view of DSO's that dissapoint so many. Once the solar minimum is out of the way, the view should be a showstopper.

Andy

[Solar B]

I think its fair to say that imaging with a PST is not easy at all...Andys images

are amazing and considering he,s only recently got one makes them even more

incredible. Brian

[beamer3.6m]

Why is it so hard to image with a PST?

[frogbmth]

Thanks for the thumbs up Brian! Very much appreciated.

There is a lot of talk about the PST being unsuitable for imaging. The main issue is the lack of focus travel - most webcams and CCD cameras don't come to focus from what I have read.

However there are some simple options. I simply used a low profile nose on my Imaging Source DMK which allows the CCD to sit closer to the eyepiece holder and it now reaches focus with plenty to spare. Some people use a barlow tip instead to extend the focus limit out so that there is enough focus travel to reach the CCD. I also found that the BCF Astro Engineering MagniMazx 1.6x screw on barlow allows focus to be reached easily.

Also, a monochrome cam is far more suitable for Ha work. There are some very good primers online for solar photography that describes the challenges very well. I took this advice and got the mono cam, although I hadn't expected to buy more than a cheap webcam! The DMK21 is just awesome for the price.

Some people are also getting nice results with afocal. I dont consider myself experienced or talented, and by no means any sort of expert. With some homework, patience and familiarity with image processing I think anybody can get good results from the PST - it's just not as straightforward as imaging other large objects like the moon.

Just a few weeks ago I looked at images like mine thinking it would be a very long time before I got these sort of results. I still see a whole lot of shortcomings in my solar images but trust me, imaging with the PST is very rewarding.

Andy