Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_beauty_night_skies.thumb.jpg.2711ade15e31d01524e7dc52d15c4217.jpg

Uranium235

Moderators
  • Content Count

    6,985
  • Joined

  • Last visited

  • Days Won

    25

Posts posted by Uranium235


  1. 12 minutes ago, Alien 13 said:

    Sounds good, as to price a similar Canon version would be 6K+ so its a bargain......

    Alan

    Hmmmm.    that PL thingy has got me thinking a bit. It would be so nuch better if there was a custom adaptor that did away with the whole bayonet business  for standard photo lenses, it would hex bolt to the lens (using compression) and be ultra short....lol... I know might be dffiicult to envisage, but given some time and perhaps a test 3d print (before moving on to aluminium), it might be possible.

    lol... I wish Samywang made an M48 or T2 fit version... that would be fantastic :D


  2. I was looking around for a cheap used 135mm sammy, but came across something very interesting this evening. Samyang have released a 135mm cine lens, rated at T2.2 (transmission value, rather than F ratio). Its expensive, but I found that you can get a variant with a fitting  called "Positive Lock". Which gives a much more secure fit than the standard EF springs found on your typical camera mount (as cine lenses are heavy beasts).

    A little more digging found that there is a PL - T2 adaptor available, and the flange-chip distance of the lens is a generous 52mm.

    Would be nice to see someone with deep pockets give that a go for astro :) but as always, best to keep your powder dry until someone else makes the leap. Its only been released this month, so its yet to get any attention. If its anything like the standard 135, it would be quite special - especially given the secure nature of its mountings.

    The price? £1544 .... hahahaha yea right (if I won the lotto) :D:D:D 

    Weight? 1.4kg .... lol...

    Thats a lot of dough for 135mm (though probably cheap in the world of cine)

    https://rokinon.com/xeen/xeen-cine-system/135mm-t22

     


  3. It is entirely possible to get rho ophiuchi from the UK 😊 you just need a dark, unobstructed location, and pick your nights well (no fuzzy skies). 

    Now is a good time for it.  But you have to stay up well late for it...lol 

    Actually, I'm thinking of getting yet another of these lenses since my new home has such a limited window of opportunity I would need to cram in as much data as possible in just 3 hours... and the only way to do that is to go superfast.


  4. On 20/06/2019 at 16:53, Kaydubbed said:

    At F2 would you get phase shifting issues using normal narrowband filters?

    It also depends on the bandwidth of the filter.  A standard Baader 7nm filter is fine in my experience, however a 3nm Astrodon would be more inefficient. A 12nm Astronomik on the other hand would fare better.

    But hey, youre at f2!! :)  so a slight loss in transmission is no big deal at that speed.

    • Like 1

  5. On 13/05/2019 at 08:03, JohnSadlerAstro said:

    Hi,

    It's something I definitely wasn't expecting! The jet is in the correct direction though, and is in the opposite direction to the coma. It's also strongly luminous in the blue.

    I would suggest disregarding the standard method of taking short (<1min) subs, my ones were 120 and 200 sec, at iso800, I believe. It's quite possible to get the galaxy core + jet without too much clipping. 

    Good luck!

    John

    Just working on it now mate (its been a while since I last got out).

    But.... ive just checked the first sub (240s) and bingo... its there!! :) my first (intentional) jet!

    I'll leave the camera running for an hour or two - just for the sake of nose reduction - and hoovering up some background fuzzies. Im getting a few unexpected bumps in RA guiding though, no idea why becuase there is absolutely no wind our there tonight.

    • Like 1

  6. On 17/05/2019 at 16:39, Adam J said:

    Rob I have looked at this a couple of times over the last year and I always wonder how you control camera rotation with this setup. Also how do you colimate?

    You have some degree of control over the rotation (prior to attaching camera) by simply taking out the screws on the tilt adjuster and rotating it in portions of 120deg, if you get it close, the rest of the camera orientation is finished by tweaking up the tightness of the extention rings (not too tight though... dont want to bind them). Its kinda arbitrary, but Ive never failed to get the camera landsacpe or portrait with it (in repect to the focuser).

    Collimation is done simply by removing the corrector (it screws out). Or... if you have a short cheshire in your box you can just leave the CC in, attach an EP holder to the M48 thread and off you go... but I do stress that it needs to be a short cheshire - otherwise you will hear the glorious sound of metal on glass... not good! :D


  7. On 30/04/2019 at 20:49, JohnSadlerAstro said:

    ZoomedJet.jpg.51ec627bbccd0f7894c477104fba6cf5.jpg

     

    Have you checked if the jet correct? If it is - im impressed! Jets are something i've been trying to capture for years...lol. I dont think I have a close up of that galaxy in my archive, so I'll have to get some fresh data while i still can.

    It might be worth me getting the 178 on that for some close-up action... and possibly enhance the jet slightly with some creative layer masking in Ps.


  8. 30 minutes ago, al-alami said:

    Apparently the night we were hit with winds gusting at around 45 or 50km per hour. 

    I tried rebuilding but the focuser is too messed up, and the metal under the focuser got really bent. So, collimation of the focuser is next to impossible. ?

    Just had a bit of a brainwave..... in future get a couple of dumbell weights and hang (or place) them on the accessory try/leg spreader, that would provide a bit more protection.  Or maybe a way to anchor the tripod?


  9. On 19/04/2019 at 00:10, al-alami said:

    I am sad to say that my 130pds has seen the last of it's imaging days.  I very strong gust of wind blew it and my mount (HEQ5 Pro) over.  The tube has got good selections of bends in it, and the focuser is a mess. ?

    I took everything apart and rebuilt it, but it seems the metal under the focuser is so bent out of shape that the focuser doesn't sit right anymore. I won't even talk about the focuser needing a helping hand to focus properly, so focusing is a 2 handed process.

    So basically it's easier and cheaper to buy a new one than to fix it. ? 

    Unless someone has a used one they don't want any more! :p 

    Sounds awful mate.... that must have been some gust of wind! Ive never heard of an NEQ5 being blown over before.

    To look on the bright side, the 130 isnt an expensive bit of kit to replace and your camera was not damaged. Just think what it would be like to have a nice APO and CCD camera hit the floor!... ouch! :) 


  10. On 16/04/2019 at 17:23, Adam J said:

     The 178 will be better for small galaxies due to the 14bit A/D and the ASI1600mm pro or a KAF8300mono camera will be better for nebula work, I would not discard something like a 460EX either.  

     

    Exactly what I would have said :)

    The 1600mm and KAF8300 have roughly the same sized sensors, so it should work (with a little tweaking to get the flattest field possible). The 1600 is cheaper, so that will allow extra headroom for a couple of filters etc if the budget is around 1k ish. Get a Ha filter first, that will do the most for you (well... in about 2 months when the MW swings back around). Even so, the resolution with the 1600 is 1.2" p/p - which is still pretty damn high, but not so high as to exceed the resolving power of the telescope aperture (~0.9").

    The 178 is best used either as a galaxy buster on the 130, or if you want a larger FOV - mount it on something like a Samyang 135mm f2 or the 200mm Canon EF lens.

     

    The 178 with a 135mm lens:

    31991945237_5294ee1b16_o.jpg

     

    And the 178 with a 130pds:

    41872415692_445752a6f7_o.jpg

    Massively different FOV sizes there.

     

     

    • Like 5

  11. 23 hours ago, JP50515 said:

    Uranium it's good to so you're still here in this thread after all these years. Honestly mate I chuckle at one of your earliest comments regarding Skywatcher paying this thread commission for uptick in 130PDS sales...more like paying you commission! I think your images are the reason that a large number of us landed on this scope, and to this day I am beside myself to understand how you pull such amazing data off a cheap imaging newt mounted to an EQ6. 

     

    21 hours ago, matt_baker said:

    I can agree with this for sure. 

    One of the reasons I got a 130P-DS was seeing a few of Uranium's images and thought there's no way such a cheap scope could grab stuff like that.

     

    Thanks guys :)

    But we have to take a number of things into consideration if you want to get the best out of it.

    Starting off with the mount, the 130 is quite light so it never bothers an NEQ6 (not even close...lol).

    Secondly there is the camera, that is were the magic happens - which as we all know can only be achieved with a mono (yes... there, i said the M word :D ) CCD or the one of the recent crop of cooled CMOS cameras because you need very low noise to get good data. This point would need a lot of consideration in regard to sensor size and/or pixel size, and what you want to image.

    Then, its the 130pds - probably the simplest way to deliver photons to the sensor..... no fancy-dan glass required  (barring the coma corrector) - just a couple of small mirrors... its as uncomplicated as it can be :)

    Lastly, its guiding, choice of target, framing and mosaic planning and total integration time.

    But at the moment, its my only telescope - so its going to get used a lot, especially now I've got it bagging galaxies with some decent detail. With the ASI178 though, ive found it takes a 100+ short(ish) subs to get a very clean image.


  12. 1 minute ago, Startinez said:

    Crikey, I think I've got my next scope sorted... I currently have a 90mm f/10 refractor so I think the two would make a good pairing.

     

    Out of curiosity, if I can afford the 200PDS should I go for that over the 130 or are there other things to consider than how much light will be collected? Same focal ratio. I guess one thing to consider is that when adding a coma corrector into the mix you're throwing another £100 on top of the scope price.

    The 200pds? Hmmm nope :) 

    It's the weight and bulk you have to consider (its heavy when loaded up), and it will catch the wind like a sail. It's easier to just get more out of shorter focal length by using a camera with smaller pixels (as long as you don't over sample the resloving power of the optics).

    • Like 1

  13. 2 hours ago, RolandKol said:

     

    By the way, while adjusting the lens holding bolts, - how do you know you do not introduce any tilt?

    I did mine very, very carefully ;)

    What I did was to sit the whole thing vertically, so the back of the camera is on a flat surface and the lens is pointing upwards. Then tighten up the bolts one by one until the barely make contact... just until you feel the smallest amount of resistance. They neednt be done up tight - the guidescope ring is just there to stop the lens flopping about under its own weight and compressing the bayonet adaptor (even though any movement is tiny, its enough to upset an f2 field).

    The 3d printed bracket looks like a good solution to that (I would probably add felt to the rings), but I would also want the camera braced.

    • Like 1

  14. 11 hours ago, Space Oddities said:

    According to their website, it's the QSI 583 WSG-5 with a Nikon adapter :) 

    Just noticed the camera in those pics... see the reinforcement/support added to the camera itself? That is exactly what I did with the Atik 383L+ so both lens and camera are supported - when operating at f2 any compression of the bayonet adaptor will cause tilt in the field, so its best to take all potential strain out of that weak spot. Getting all four corners perfect is the first essential step if youre thinking about putting a mosaic together.

    Probably not an issue with a light DSLR, but if youre sicking a big CCD or FW on it - then support will be required.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.