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jefrs

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Everything posted by jefrs

  1. jefrs

    P1130754

    From the album: jefrs' album

    By Jupiter I think I've got it! with moons too. Panasonic GH4 1 second at ISO3200 sooc jpeg with Samyang reflex 500mm f/6.3 from Newbury England on 07/01/2015 about 03:00 UTC

    © Copyright 2015 Jeff Slade

  2. jefrs

    jefrs' album

    astro photos
  3. This is a long thread which I admit I have not read all through. The OP started out by polishing a layer off with Meguiars ScratchX. I may have come across something better with Britemax Black Max http://britemax.co.uk/acatalog/Black_Max.html Obviously it's for car paint but it really is ultra fine and can remove 4000 grit marks. It will polish metals and I have used it for optically polishing lenses (kill or cure). Despite being ultra fine it is rather fast cutting: use with due care.
  4. jefrs

    P1140045cropt

    From the album: jefrs' album

    The Mouse On Orion's Sword ( weird tripod vibration ;-) Newbury, England, 16/01/2015 01:16 UTC Star Adventurer EQ Panasonic GH4 Samyang Reflex 500/F6.3
  5. My spelling is pretty good. My professional work often involved writing reports as technical author but you get a proof-reader with that. I'm also married to an english teacher. Problem is my fingerts are dyslexic now, I can barely type: osteoarthritis in every single joint and spondylitis in the bits that aren't joints. Strangely, a good work out on the guitar improves things. I use Firefox and have a spelling checker running but I probably have twice the vocabulary of its lexicon. Bless Noah Webster for he was truly dyslexic. I too will hit post and then realise I've made a pig's breakfast of it: I can easily type numbers in reverse, or say "can" when I meant "cannot" (rather significant). Ho-hum, until we get accepted as grown-ups I guess I'll just have to make another post and another post to correct stuff as corrigenda.
  6. For adaptor rings I would Google up one of our telescope specialist companies and then phone them to make sure you get the right thing. Imo it's not the usual Ebay T2 to M43 adaptor ring we want. The "T" is for Tamron, not Telescope and it's a M42x0.75 metric thread (as opposed to the Praktica M42x1.0 lens mount), but "M43" is "micro four thirds" naming a lens mount system that uses a "four thirds" (4/3) size sensor. I now have several adaptors. The normal length when mounting a legacy lens e.g. Pentax-K is about 35mm from sensor with a M43-PK adaptor. T2/M43 adaptors can come as 35mm length from sensor for reflex lenses or without the 2cm extension tube, some have a tube that usefully unscrews. There is about 15mm from mount to sensor and OEM M43 lenses are designed to focus the image at that range.
  7. It's a nice pocket camera but you might also look at the Panasonic G6 which will give you the much needed remote shutter release: should also be cheapish - under £400 w.lens, less than £270 used i.e. similar prices to E-PL5 but the E-PL7 is only a little more (and big upgrade over the E-PL5). My G5 cannot do time lapse but apparently the G6 can. Having said that the G5 has a remote socket so I can use the time lapse feed from the motorised EQ mount. The E-PL7 is an updated E-M10 without the EVF but having both flavours I can baldly state that the Pannies are better built: I had a switch knob fall off an E-M1 and the shoddy plastic hot shoe cover for the E-PL7 self destructed. Unlike entry-level DSLR the kit lenses on M43 are pretty good glass, although the 14-42EZ does have reports of jamming and which is why I use the PZ14-42 on the E-PL7. My E-PL7 does suffer from a hot sensor when shooting video, burst shots and long exposures, wrong camera for job. My Pannies (except wife's GX7) have the sensor firmly mounted on a heat sink, they do not get hot. Keeping the sensor cool can be important for astro work.
  8. I re-read the OP's post. Rob is considering the E-PL5 which is probably discontinued hence should be even cheaper than the E-PL7 which has many better features than the E-PL5/6. The E-PL6 was a cosmetic upgrade but the E-PL7 is a big step, I think they are trying out some stuff for the new E-M5 mk.2 One advantage of Panasonic over Olympus for this work is the sensor is mounted on a heat sink, hence less noise from long exposures which do heat the sensor up: the sensor is right behind the monitor screen and the back does get warm to the touch, which produces "hot pixels". The G5 has an allow body frame and the GH4 chassis is designed as an effective heat sink; they stay cold. I have never used the G6 but it has more features than the G5 and could be ideal.
  9. Sorry, they do not understand "compact system camera" :- The Olympus Pen Lite E-PL7 has interchangeable lenses. The E-PL7 is not a "compact" camera. It is an updated E-M10 without the EVF. The E-PL7 is a mirrorless micro four thirds system camera: I have one and it is compact, it is my "pocket" camera, it's fun to have a tiny 16Mp camera that takes top quality pics. The sensor on M43 cameras is some 2cm closer to the mount than a typical DSLR e.g. Canon, because it has no mirror. Yes it can mount with adaptor on the telescope focus mechanism with the correct adaptor(s) The E-PL7 has no remote cable shutter release but I suppose we can use WiFi control. The E-PL7 tilt screen is at all the wrong angles on a telescope, so is wife's GX7. The 130SLT is actually my wife's telescope, as I'm a physicist-engineer (radiological metrologist) I get to be the tech support. Hence I prefer one of my Panasonic M43 with their fully articulated screens. My G5 cannot do time lapse, my GH4 costs an arm and a leg. Mirrorless cameras do have the sensor exposed when the lens is removed (permanent live view). I got some black smuts on the sensor changing the lens in the dark (I can clean sensors but prefer not to) Be careful. Hence I recommend always fitting a Barlow and/or eyepiece in a clean room to seal the sensor housing up: black smut problem solved. Due to the short sensor to mount distance I am getting some issues with back focus. I find something like a thin adaptor ring onto a 2X Barlow w/o eyepiece or a 2cm M43/T2 adaptor onto a "short nose" is giving best results so far as other configurations with an eyepiece inserted seem to want the camera closer to the secondary mirror than the focus mechanism will permit. Either that or I get very severe vignetting. If an eyepiece will fit inside the T-adaptor i.e. 37mm long, then an eyepiece can just about be used; most are longer or too wide. I have not solved this yet, in fact I came on the forum just now to see if I could find out how others are mounting cameras to reflectors. My alternative is to put the camera on the Star Adventurer EQ mount with a 500mm or 800mm reflex lens i.e. a telescope lens, but that lacks the Goto of the Celestron. I am old enough to remember clockwork EQ mounts Alignment can be fun because you have to see Polaris and it doesn't always cooperate.
  10. Thank you for rplying. I'm sad that you had those problems in the past but its seems the current inhabitants are perfectly polite. Imo is it now a silly rule.
  11. It is raining now but the worst of it is that it is completly overcast. On astronomy reading matter I have to reccomend anything and evrything by Sir Patrick Moore. Not only extremely knowlegable but also a very good writer. Currently delving through Patrick Moore and Pete Lawrence "The 21st Centurey Astronomer" ISBN 978 1 78177 125 9 sub titled "The Practical Guide To Observing And Photographing The Moon, Sun, Planets and Stars In The Digital Age" basically everything you never wanted to know here and it's bang up to date. Sadly I only got to meet him the once.
  12. I have only been here a short while and I have arthritits, I typo frequently and need to edit posts regularly. Why on earth do you force newbies to post 250 times before they =cam edit? No other forum does that and th einhabitants here seem reasonably intelligent and well mannered enough that editing a post would not be a problem. Daft rule.
  13. From the album: jefrs' album

    Orion Nebula 13/12/2014 22:30 GMT/UTC Newbury England 51.4N 1.34W Panasonic GH4 Lumix G Vario 100-300/F4.0-5.6 at 234mm f/5.6 1second ISO3200

    © Copyright © Jeff Slade 2014 All Rights Reserved

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