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Uranium235

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Everything posted by Uranium235

  1. Samyang mod now available from FLO https://www.firstlightoptics.com/adapters/astro-essentials-samyang-lens-to-m48-adapter.html Product discussion thread here: From what it seems after discussion, is that there is a good chance it will also work with the manual 85, 50, 35 and 14mm lenses (canon fit). Hopfully someone can verify this over time.
  2. 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).
  3. 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. 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
  4. 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 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.
  5. 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.
  6. Quick update chaps, the Samyang mod will be available from FLO shortly.... watch this space
  7. Thanks Its the QSI683ws camera (KAF8300), and the lens was stopped down to f4.
  8. Its been a while, what with work, Christmas, and endless cloud getting in the way of things. But I've gotten a few images out of the modified lens now The only downside, this particular lens is not quite on par with the two Ive had previously - so Ive had to stop it down a bit. The following images are all fairly short runs, just over an hour for each, and absolutely no calibration:
  9. You very seldom get a flat field with a zoom lens, questionable levels of CA too. Fixed, prime lenses are always better.
  10. This is the one I used: https://www.teleskop-express.de/shop/product_info.php/info/p2742_TS-Optics-short-Adapter-from-2--to-T2-thread---Rotation-System.html
  11. Example of a dovetail adaptor: (attached to the CC via M48)
  12. Compression rings are a waste of time/money, and the clicklock eats up far too much backspace for it to be of any use to the imager. Two best ways are either screw fit, or three screws with a dovetailed 2"-T2 adaptor.
  13. Vignetting is pretty much unavoidable with the 130 (or pretty much every other telescope to some degree), depending on the size of the sensor. Same goes for coma.... BUT .... that is what flats and coma correctors are for I got the KAF8300 sensor working with the 130, but only after a few modifications to the telescope. But if youre talking about full frame as in 35mm....lol.. no chance. There are very few astrographs that can cope with that (and the ones that do cost a mint).
  14. Its not quite in true focus Dave, so there may be more to come the filters are now clean, but I didnt get a look at the sensor since the shutter was closed.
  15. Taken some test flats to see what the illimination might be with this camera, some darkening in the corners but I reckon the flats will sort that out on real data: Taken @f2
  16. Oh, and ive just checked the technical drawings for the 683 camera... it appears the filter is ~20mm away from the sensor surface. Hmmm.... it might work, worst case scenario would be that I have to take it down a few stops to correct any vignetting from the filters.
  17. Only the first couple of minutes are relevant for this, but even getting the bayonet off seems like a bit of a pain.
  18. Ive just looked at what it takes to disassemble a typical canon (200mm) lens - its much more complicated, but not impossible. Like I previously thought, the engineering involved would have to be bang-on for it to all go back together as it should:
  19. Things just got serious: Not sure how its going to cope @f2 as the QSI has 1.25" filters, wont know until I try it I guess.... but I've found the camera has a photo screw hole on the case, so ive just bolted it directly to the dovetail bar. The lens mod takes care of everything else, no need for further support EDIT: Actually, I can test the illumination/vignetting later tonight - I'll just set the lens to infinity and take a few flats, that should tell me roughly whats what.
  20. The canon 200mm bayonet seems to be held by 4 screws. But whether all the electronics come out with its removal is unknown. With that in mind, the engineering would have to be precise. I need to see one in bits tbh.... but I dont think anyone is that brave...lol.
  21. Yeah, the lens mod at the moment is only suitable for manual Samsung lenses. Canon autofocus lenses have electronics in the way, which might make disassembly and modification difficult (the Samsung can be modded by a monkey it's that easy). I'd have to get my hands on one and take a closer look to see if its possible.
  22. Im just waiting for the dust to settle being as the SGL star party was cancelled. Then I'll ask FLO about getting a small production run sorted., maybe just kick off with 10 and see how we get on.
  23. Oh ... no... I was hoping that this would be my only break in the run up to xmas gutted.... Oh well, cant be helped I suppose! Safety first, even if it was open I suspect a number of the roads will be impassable as well - Ive already had a couple of dodgy moments on country roads here in Worcestershire, I waited for someone else to try and drive through the flooded bits first before trying (very carefully) with my little car
  24. Clear tonight, so time for more testing.... 46x240 on Andromeda:
  25. Hmmm interesting reading! I guess this could (in theory) apply to mounted filters since it takes little effort to remove one from its cell and flip it over. Might be something worth trying if you are getting large halos on your particular setup - I wonder if this applies to narrowband filters? (probably not, but its worth asking)
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