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Uranium235

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Posts posted by Uranium235


  1. 19 hours ago, Knight of Clear Skies said:

    Excellent thanks, added to basket. Always good to have a recommendation rather than taking a punt.

    When it turns up, you will notice it has a grid pattern on the illuminated side. That will disappear once you put a few sheets of A4 on it - you probably need about 3 or 4 sheets to dim it sufficiently enough for lum flats on its lowest setting. For narrowband just hit the power key once or twice to increase the brightness (you have three levels). It runs fine for ages from a small powerbank

    • Like 1

  2. FYI, the lightbox I used was this - 14 quid from amazon:

    6174ZcRYlAL._AC_SY450_.jpg

    I then created a protective cover and OTA attachment using the box it came in, and a bit of foam :) oh, plus 3 sheets of A4 to further dim and diffuse the light. The pic shown is with it on max brighness, I've only used the lowest setting so far on lum data. NB will probably require it to be kicked up a notch or two in brightness. Its amazing what you can do with a bit of glue and tape :D:D 

    20200421_085840.thumb.jpg.ba1e7b836727bbbe1838ba005138d3b4.jpg

    Probably needs a bit more tape around the edges, just to make it star party friendly.

     

    • Like 3

  3. Testing the new lightbox I built tonight, it seems to produce much better flats than a monitor - runs off usb power with variable brightness, which is great  :)

    Just applied it to some M106 data I took a last week, which I didnt post here because the background was a bit blotchy. Flats from a different source seem to have cleared this up somewhat.

    M106-improved_80.thumb.jpg.990eb212d5febfe18860b03f78f89e41.jpg

    • Like 8

  4. Quick update on my quest to collimate via a camera.

    Given up on the pinhole concept for now, as I spotted a super cheap 8mm CCTV lens (cs mount) that will work with either my QHY5 or 178mm camera. I can just pop that on and collimate / tinker until im blue in the face :D


  5. 7 minutes ago, Davey-T said:

    No idea, seem to recall from distant school days that pinhole cameras were something like f/50 ?

    Long time ago so could be talking rubbish, and not for the first time 😂

    Dave

    Yeah, just looking ar a few examples done with a dslr. Its possible but to improve the sharpness I need to make the hole smaller. 

    I will do a few experiments when I have a spare evening this week 

    • Like 1

  6. Just putting my thinking cap on about something  - namely how to collimate this (and other newts) with the imaging camera in place.

    Previous thoughts about this always involved putting a short focal length lens where the filter would be... however... today I had another idea.

    Astro cameras are very sensitive things and can easily cope with a high f ratio. So, what about doing away with the lens concept and using a pinhole instead? 

    It's cheap, anyone can make it, and with a few careful calculations should deliver the right focal length required for taking images of the secondary mirror.

    Daft idea? Maybe... maybe not 😄


  7. 8 minutes ago, mAnKiNd said:

    Impressive that you built one. Yeah, no rotation is a bummer, but I suppose I've learnt to live with it.

    I took off (and lost) the rotation ring on the FUFmpcc because it compromised stability, which was my whole purpose for using these adapters.

    I was pretty lucky in that mine rotated to portrait (with respect to the focuser) right at the point where the threads started to really tighten up. If it was to far before that I'd either have to come up with a different configuration - or take a chance and tighten it up as much as poss until the right camera rotation is achieved.... but the big danger with that is a cold-welded thread (never much fun to try and undo). Thats why I apply boot polish to my threads to reduce or prevent binding when doing things up fairly tight.

    • Like 1

  8. Many apologies for the late(ish) setup for this, but (yay!) its now time for the 2019 imaging showcase!! :)

    Please use this thread to showcase your best images captured during 2019. Just one post per member but you can include up to 5 images if you want.

    The thread is for all imagers, both novices and advanced.

    Please keep details to a minimum - scope and camera possibly along with a few comments.

    The thread needs to be packed with images so please don't respond to the postings. The previous years showcase thread(s) can be found here:

    https://stargazerslounge.com/forum/203-imaging-showcase-threads/

    • Like 4

  9. 5 minutes ago, Davey-T said:

    And 14mm f2.8.

    Dave

     

    That looks almost identical! :) You will notice that the three screws are not quite 120 degrees apart - one of them is offset by about 10deg, same as the 135mm.

    What it looks like is that the rear end of all the MF canon fit lenses are the same construction, just with different optics upfront (makes sense to keep production costs down).


  10. More on spacing... You can see the M48-T2 adaptor (plus delrin spacer) im using is roughly 8.5mm, and the distance from the camera T2 plate to the sensor is a whopping 35.5mm.

    20200114_220032.thumb.jpg.8b8312f52d633d9a72d4b606fd6a4e96.jpg

     

    Both add up to the magic number of 44mm, when setting up your spacings, dont forget to add distance when using filters.

    Example:

    Astronomk: +0.33mm (may not need to bother)

    Badder: +0.66

    Astrodon: +1mm

    It might not seems much, but 1mm can put you well short of infinity focus. The camera im using has a mixture of Astrodon and Baader filters - slighly more complicated :D


  11. Okey doke, back in front of a proper keyboard now: :)

    As for the question of other lenses in the Samyang range, I have to stress that this mod is for manual lenses only - as the electronics invoved with an AF lens would simply get in the way.

    Now, looking a the bayonet for the 85mm Sammy - it looks like the mounting is suspiciously similar to the 135

    21%2001%202015142186029085mm%20Cine%20Mk

    I suspect the 50 and 35mm manual lenses would follow suit. So if you already have one of those in your box then there may be a good chance it would work.


  12. 6 hours ago, Adam J said:

    I asked Uranium about this several months back and he said it was in the pipeline so glad to see this. The samyang 135mm is one possibility for my coming mobile setup. 

    I wonder if there is room for a filter draw and a filter adaptor...

    Great Idea. 

    More than enough room, you can use a standard thickness filter wheel which is usually about 21mm and still have room left for whatever adaptor and extension rings you need.

    Always better to space it just short to start, then add a delrin spacer or two in order to get it focusing as close to infinity as possible.

    I'm chuffed that one of my ideas actually turned out to be useful 😄

    I'm out working at the mo, but I'll fill in with more info when I get home. 

    • Like 1
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