Sunday, June 2, 2013

Full disk solar images...again..and the DMK41 adapter debacle...

The PST is a great scope for the money, but damn...imaging was the last thing on their minds when they designed it. There are only two ways to obtain focus when imaging through a PST: Barlow, and short, shoulderless nosepiece about 25mm in length. I had got my my raise backpay at work and as luck would have it, it allowed for the purchase of a DMK41 from The Imaging Source. I was hoping to do some full disk shots.

I ordered a shoulderless c-mount nosepiece from OPT and had it in my head that in order to facilitate the new nosepiece that I would have to remove the c/cs adapter ring from the camera housing. Apparently in the past, these little guys just unscrewed from the housing, but modern incarnations have two set screws holding the adapter ring in place. This is important because while researching this I found tons of posts saying that you had to remove the adapter, but none mentioned anything about the setscrews. Users at the Solarchat forum got me squared away on the info and one screw came out without issue. The other woudn't bite (it was a regular type screw needing a tiny blade type screwdriver, but half the head was missing and the blade tip couldnt bite). I tried drilling it out to no avail. I attempted to remove the ring with pliers, but I only got it about three revolutions before irreversibly locking. After much stress and heartache, I accepted that the adapter ring would never be removed. As it turned out, the new nosepiece came in and it threaded right into the small thread. Guess it didn't need to come out after all, which is a good thing.

I didn't have a vice at the house, and let me tell you that trimming the nosepiece with a hacksaw was a short. I got it done though, and despite the fact that it is ugly as hell, it does work nicely.

Here are today's results: Setup is DMK41 and stock PST on a SmartEQ mount. 1539UT / composite for proms and disk detail..





As you can imagine, I am very happy. The DMK41 performed as expected, nothing to note against the past performance of my old DMK21. Barlowed images do have the occasional newton rings, but usually they can be dealt with. Not bad despite the PST being one of the most difficult scopes to image with.

6 comments:

  1. Awesome pics Andrew, I definitely have a DMK41 on the list for next year's b-day present. I think I took my pics at almost the same time as you yesterday. I used a "redneck cam" I kludged together from an old webcam. My pics are at

    http://tinyurl.com/h-alpha-solar

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  2. Those were some sweet pics for afocal! You can't beat the lunt 60, I had the tilt tune model. Regret ever trading it. The pst is good visually, but it is a nightmare to image with. I gotta say I love your mount :) I have the non-pro version and love it.

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  3. Super pics Andy, really love the color choices. I have the DMK21 with a Coronado 60, but can't quite get full disk either, so hopefully one day an upgrade to the 41 will come. Btw, the DMK21 makes a decent live view camera too, I'm very surprised at the versatility of that cam. Both the PST and any of the Coronado's have their challenges when it comes to imaging, but once you get the hang of it, Ha is so addictive no matter what instrument you use.

    Thanks for sharing.

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  4. Awesome disk solar images from dmkm 41. get your online horoscope from viswanatha saraswathi guru. He has got something great to explain about planetary positions.

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