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About DavidDench

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  1. Thanks all. Just grabbed an image from today - poor seeing, very wobbly. A quick process ( a bit heavy handed ).... Tal/PST mod, PGR Grasshopper3, 20 frames stacked
  2. Dear All, just got round to processing this from yesterday. SM40 unit on front of 80mm F6 frac. PGR Grasshopper3 camera, 30 frames stacked. Please see full size image. Best wishes, David
  3. I don't post very often, but got a half decent image after lunch ( about 2.00pm )today. Tal/PST mod, native FL, PGR Grasshopper3 20 frames stacked. Best wishes, David
  4. I do not think it is a cooling problem as the scope is permamently mounted in an outside obsy at ambient temperature. I have also imaged at all times of day as a test and in all seeing conditions. turbulence over the intervening fields is an issue but is also be an issue with the 8" f/8 newt that does not exhibit the same visual/imaging discrepancy. As I have already pointed out I have tried using sunlight reflections off distant shiny objects as stand in star tests. I am not sure what actual star tests would show over a well illuminated scene with decent contrast targets and very short exposu
  5. Just to give a non-scientific illustration of what I am talking about, I have posted some example images. Here is a full frame ( 2x2 bin ) with a bit of noise reduction to reduce file size from the 8" F/4 Slevogt using the Canon 550D. http://myweb.tiscali.co.uk/daviddench/temp/slevogtbin2fullframe_filtered.jpg Here is a 100% crop from that original image ( again no processing other than noise reduction to reduce file size ) http://myweb.tiscali.co.uk/daviddench/temp/slevogtcrop100pc_filtered.jpg And just for comparison, a crop from an image using an 8" F/8 newtonian using the same camera on a
  6. Thanks for the replies. Focusing with the camera is not a problem. More than enough focus travel to get inside and outside of focus point. I have video'd a distant daytime bright spot through focus and examined the patterns ( a handy facility of the Canon 550D ). The scope seems plenty well collimated enough to produce a decent visual image. Focus point is pretty critical but achievable with the focuser and using 10x liveview on the camera. I feel that I am missing something in terms of the camera/scope combination as I can see a very detailed image but just cannot image anything like that qua
  7. Dear All, Sorry about this cross posting but need a few experts to ofer suggestions. I am trying to resurrect one of my old scopes but have hit a bit of a brick wall with my knowledge. I am hoping that one of the experts here can give me a push forward ( bad mixed metaphor there ;-) ) I have an 8" F/4 Slevogt that was designed to give star images less than 25 microns in diameter across a 60mm diameter field. Sadly all my old photographic gear has gone so I can't exploit that facility now. I am just testing out the optics using a liveview canon 550D across a reduced field ( approx 4.5 micron pi
  8. This is a bit of a dim question. I have done a search but can't find a proprietary solution ( might have missed one ), hoping someone here will put me straight. I have a nice WO SCT focuser that I want to use ona Newt ( with a flat focuser mount surface ). What I need is a flat plate with a male SCT thread. Anyone know of a source for one of these, or a way to cobble one together from disparate parts ? Many thanks, David
  9. Break in at the Astronomy Centre Todmorden There has been a break in at the Astronomy Centre Todmorden, Unfortunately a lot of kit has been stolen. A full inventory will follow. This is a public outreach facility and is Peter Drew's life work. This is a big blow for the club. The Astronomy Centre Please be on the look out for new adds for Coronado scopes and Solar scopes that have been modified. Large refracting binoculars and large reflecting binoculars in particular. Please pass the word and inform the police and the Astronomy Centre if you have your suspicions. If you can help by p
  10. Here is a a quick effort using the wavelets in ImagesPlus nov 27th 11-09pm raw stackDJD.tif
  11. Can someone give some quick guidance ( sorry if it has been asked before but I have searched, honestly ). I have a virgin Vista desktop that I am going to install SharpCap on to. I am about to modify a Lifecam Cinema. What ( apart from SharpCap ) do I have to install onto the desktop to drive the lifecam to its full fps capabilities ? Thanks, David
  12. Dear All, I am thinking of turning my solid tubed 12" F/6 Newt into a truss tube Dob. There are some lovely components available abroad, but are there any ready sources here in the UK. In particular, truss tube mounting assemblies ? A search here and usual places didn't turn anything useful up. Anyone have any spares ? Thanks
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