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Primitive PST Captures


samtheeagle

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Rather unusually I have been blessed with clear skies to go with my new telescope purchase. So first thing I was out with my PST :) Still learning the ropes, but I just can't resist trying to capture the things I see through the EP! So here are a few from early today... All captured using ShapCap with a Microsoft HD webcam, and stacked with Registax.

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I reduced these to B&W as I think it helps to bring out the surface detail.

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I did look at those cameras, but having just spent all of my back dated pay raise on the PST I needed to find a cheaper option... I decided to get Astronomiser to replace the CCD on a spare SPC880 webcam I had laying around, so for approximately £75 in total I have a lovely mono camera capable of 60 fps :hello2: It seems to be VERY sensitive, which is exactly what I'm after. By way of example here's a very exciting sample of the wires under my work desk! :hello2: The first image is ~100 frames stacked, the second is a single frame taken from the avi. On this evidence I'm hoping for great performance from this modded cam.

Photo Album - Imgur

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I did look at those cameras, but having just spent all of my back dated pay raise on the PST I needed to find a cheaper option... I decided to get Astronomiser to replace the CCD on a spare SPC880 webcam I had laying around, so for approximately £75 in total I have a lovely mono camera capable of 60 fps :hello2: It seems to be VERY sensitive, which is exactly what I'm after. By way of example here's a very exciting sample of the wires under my work desk! ;) The first image is ~100 frames stacked, the second is a single frame taken from the avi. On this evidence I'm hoping for great performance from this modded cam.

Photo Album - Imgur

My god that is impressive stuff!!

There you go again finding great mods to save money! :hello2:

Fantastic! :hello2:

Michael

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To continue my Neanderthal solar imaging efforts I attempted a mosaic when I got home from work today. Not ideal conditions, the Sun was getting low, and I was rushing before it dropped below the roof tops...

I'm very happy with my mono modded SPC900, which is why I was desperate to get some more captures... It's much more sensitive, and having been rehoused it happily come to focus without the aid of a barlow lens, which is nice :p So on to the image:

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Yeah. It's rough. I can't find any software that will do a good job of stitching together my images ;) I managed to get ICE to do some, but then had to bodge others in by hand with lots of layer moving a resizing. But it's a first, and hopefully the only way is up :( I also probably did this the hard way... One Mosaic for the disk detail, and one for the proms. Is that the standard approach, or should I be aiming get get both surface and limb details in one capture?

So all of the other full disk images I marvel at here, do people mosaic somehow? Or do they manage to get the whole disk on the sensor? If anyone has some nifty solar mosaicing tips I'm all ears! :D

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@Michael - I went for the cheaper £60 one, which I think is the ICX098BL. Going mono really has made a difference, the surface detail pops out much more on my netbook screen making it much easier to tweak the focus. And no, you certainly don't need the LX mod for the Sun! :D I leave it at 30fps and then play with the exposure and gain settings to bring out the bits of detail I'm interested in.

And for the both of you... Yes, I understand that the SPC900 wont come to focus if left in the original camera housing. The sensor is set too deep inside the body. I never even tried it, but I presume everyone else knew what they were on about. As I had a spare plastic enclosure hanging about it seemed like a good idea to try and rehouse the electronics with the CCD as far forward as possible. I'm afraid I don't have any pictures of the internals handy, so I'll try to describe what I did. This will only make sense if you've taken one of these cameras apart and know the bits I'm on about... Thinking about it the LX modification webpage has some great pictures of the internals: http://www.home.zonnet.nl/m.m.j.meijer/D_I_Y/spc900nc.htm

First, I removed all of the electronics from the original housing. On the front of the camera there is a black plastic enclosure that surrounds the CCD. It's square at the bottom, with a cylindrical part at the top where the lens/nosepiece screws in. I took the lid of my enclosure and made a hole in it so that the cylindrical part of the CCD enclosure could poke through it. This places the sensor only a few millimeters inside the new housing. I fixed the electronics in place with a few blobs of hot glue, not particularly elegant, but effective. Then I used a "regular" nosepiece, that is not one of the specific long variant ones that you usually need for the SPC900 cameras. This allows me to insert the camera all the way into the PST, so that the casing is tight against the EP holder.

Hope that makes sense?

Edit - I forgot the pic!

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You need different exposures for the surface and the proms, so at least two exposures. Mosaicing(?) is a dark art....using artificial "flats" can help to suppress the sweet spot effect but it's still a PITA, almost as bad as trying to do animations!!

Anyway, well done!

Onwards and upwards.

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Thanks Ken, good to know that I shouldn't be trying to get a middle ground for exposure. Hopefully I'll be getting some whitworth bolts in the post soon so that I can put the PST on my mount. Proper tracking on a rock solid mount will make capturing videos much easier than on my rather flimsy camera tripod.

Could you elaborate on artificial flats please?

Funny that you should mention animations, I was just musing about trying that yesterday :D

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When taking detailed surface images (I've not heard of it being used on a full disk image - but you never know....) find an area of the surface which is spot free and slightly de-tune the etalon - take an image...this can then be used as a "flat" to remove dust bunnies and some of the sweet spot or newton rings....

Not my original idea, I can't remember where I picked it up....

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Ahhhhh, I see. Very cunning and definitely worth a try. The sweetspot does making stitching images together a bit tricksy.

My mission for this weekend is to butcher a spare nosepiece I have, to make it as short as possible. Then maybe, just maybe I'll be able to get my 0.5x focal reducer to come to focus and get the whole disk in one shot. That'd be nice. I wont get large final images, but I also wont get the mosaic nightmare :D

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Very true... Once I have the PST mounted on the HEQ5 (overkill? :p) I might see about knocking up some kind of mosaic helper app for ASCOM mounts. I know that the EQMOD project has a similar facility, but my mount is of the basic variety (with hand controller mod). I'll do some googling before I hit the code tho :D

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