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johninderby

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Posts posted by johninderby

  1. If I was asked to recommend a pair of Astro binoculars it would be the Penatx 20x60 PCF as they aren't too heavy, have built in field flatteners, and are capable of showing Saturns moons. Super sharp and clear images.

    My second favourite was a pair of Swift Ultralite 8x42s. Very small, light and compact but gave great views but have been discontinued. Can't believe I was stupid enough to sell them.

    John

  2. One thing to note is that according to the post on Cloudy Nights the hand controller being used has firmware V3.06 and the latest version available on the Skywatcher website for download is V3.05. However the NZ dealer said just to download the latest firmware available on the site.

    Don't know if V3.06 is essential to make the GOTO work, but waiting to see how Steve gets on with the test.

    John

  3. Thanks to Robert at New Zealand Telescopes for the following info.

    "We use a standard Synscan controller, it uses special firmware that is used for the AZ mount gotos such as the Mak127 from skywatcher. Also requires a special cable.

    If you can find someone that sells the Skywatcher Mak 127 on AZ mount, you should be able to obtain the bits you need, controller, interface cable, than download the firmware from Skywatcher .net website.

    New Zealand is the first place in the world to offer the goto with the Dobs."

    Steve, price for the dob GOTO kit please.

    John

  4. This thread is now in danger of deteriorating into vendor bashing and that sort of thing doesn't belong on SGL. There are other forums that good at that anyway.

    Yes OO was wrong in assumng that the customer would know that some defects on such a badly worn mirror wouln't be cured by recoating, but they did offer to recoat the mirror again if the customer wasn't satisfied. So I'm waiting to hear how it performs when actually used in a scope.

    John

  5. It would all depend how deep the defects run. Shallow ones should polish out with perhaps a few small ones left. I hear that the Hilux coatings should last about 25 years.

    When I spoke to OO about having a Lightbridge 16" mirror redone last year they quoted about £500.00 for polishing, recoating and Hilux. And while it would improve the performance of the LB mirror a lot there would probably be a few small defects left. I ended up selling the LB and getting a 14" OO dob 1/10PV 99 Strehl and have never regretted it.

    It would be intersting to see how the mirror does perform though even with the defects. I suspect it will be much better than you expect.

    Anyway here's a photo of my OO 14"mirror.

    John

  6. I see that the mirror in question was only recoated and was not polished, so any existing surface defects would still be there.

    I think that there's a lesson here for anyone thinking of having a mirror recoated by any company. Ask for a condition report on the mirror's surface after the old coating has been removed to see if it needs repolishing or if just recoating will be sufficient.

    John

  7. I used some M5 countersunk head bolts through the dovetail with nuts on the inside of the OTA. I painted the nuts black before putting them on and then touched them up with more black afterwards.

    I think you might want to countersink the boltholes in the dovetail so that the bolt heads are out of the way.

    You can get the bolts cheap on eBay, just look for M5 countersunk bolts.

    John

  8. Hi

    I agree with the previous posts. FeatherTouch is the best for build quality, but MoonLite are very good as well. The Baader Steeltrack handles weight just as well as the Moonlite and is equal in feel and precision.

    The Skywatcher is a nice focuser for the money, but not as smooth as the ones previously mentioned and doesn't handle heavy eyepieces as well. The dual speed crayford sold by ScopesnSkies now comes with two bases and is a bolt on replacement for a Skywatcher.

    One thing to consider though is that cheaper crayfords such as the Skywatcher are designed to fit 8" and up tubes so they flatten a 6" tube a bit when they are bolted down but still work OK.

    I've got a FeatherTouch and a Baader Steeltrack and had a MoonLite.

    John

  9. Hi

    Taking off the corrector cell is no problem, just mark it so you put it back in the same place. When I did it on a 127 that I used to own there was no effect on the collimation.

    However unscrewing the rear cell from the tube is a bit more of a problem as there is a thin rubber O ring between the cell and the tube which invariably breaks when you unscrew the cell. Also the cell may be very reluctant to start turning. Better to cover the mirror while drilling. I used cling film.

    I took it apart to fit a dovetail and a carry handle.

    John

  10. Hi Steve

    It depends on what the seeing is like. On a good night I start with the 17mm Ethos, but if seeing isn't that good I prefer the 26mm Nagler. It copes better with poorer seeing conditions. If it's going to be lunar/planetary I start with the 6mm Ethos.

    Actually I haven't really had that much observing time with all the eyepieces :):) as I've only just completed the collection, but I can't wait for the darker nights to really put them to good use!

    John

  11. Dream Eyepiece Collection - At Last !

    It's taken awhile but I've finally managed to put together my dream eyepiece collection.

    • Televue 3-6 Nagler Zoom
    • Televue 6mm Ethos
    • Televue 10mm Ethos
    • Televue 17mm Ethos
    • Televue 26mm T5 Nagler
    • Baader MPCC
    • 1.25" Supreme APO barlow element
    • B&W Outdoor Case - Type 30

    I've gone through quite a few eyepieces over the last few years, but after finding out just what focal lengths I used most often I distilled it down to something that could be achieved with just 5 eyepieces and suits everything from my 4" APO refractor to my 14" dob. Thanks to a sizeable contribution from the family (birthday present) towards the 26mm Nagler and the proceeds of selling some astro gear I was able to finish off the collection sooner than expected.

    The Nagler 3-6 zoom is a great high power lunar/planetary eyepiece with the flexibility of a zoom, but still as good as any other Nagler. The APO barlow element can be added to make it into a 2-4 zoom without any degradation in performance at all.

    The 6mm Ethos is also used for lunar/planetary in the 4" APO and the dob, and is one of the sharpest eyepieces with the best contrast I've ever used for planetary observing. The only other eyepiece that I've used that compares to it in performance is a TMB 5mm Supermono that I used to have. Yes it's got that 100 degree FOV but it's the optical performance that stands out the most to me. The APO barlow element also works well with this eyepiece as well.

    The 10mm Ethos performs just as well as the 6mm when used as a high power eyepiece in my Mak or as a medium to higher power eyepiece in my APO or dob.

    The 17mm Ethos is my medium power eyepiece and there's nothing more that I can add that hasn't already been said in various reviews, fantastic eyepiece.

    The 26mm Nagler T5 is a great low power eyepiece. I chose it over the 31mm Nagler (they were about the same price) as it will be mainly be used in a fairly light polluted urban environment. The 31mm would have some advantages under really dark skies but that's not where it would be used very often. Also the 26mm is smaller and lighter than the 31mm and as it's about the same weight as the 17mm Ethos the two can be swapped around without rebalancing the scope.

    B&W Outdoor Case - Type 30. Not cheap, but worth every penny when you consider the value of the eyepieces inside. "B&W protective cases that offer total protection for your equipment. Unbreakable (withstands a 3m fall onto concrete), watertight down to 5m, airtight, dustproof, chemical resistant and corrosion proof".

    John

    PS

    Yes I'm the one responsible for the cloudy and rainy weather forecast for the month of August.

  12. They're a good quality zoom. While they're made in the same factory and have the same optics as the Televue zoom, Televue does their own additional quality control checks. Also the Televue has a clickstop arangement.

    They're also the same as the original Celestron 8-24 zoom. Unfortuately a few years ago Celestron replaced the Vixen made one with another and much inferior one.

    Overall not as good as the Hyperion zoom, but if you can get it at a good price (£50.00 - £60.00 or less) I'd still recommend it.

    John

  13. Better quality green lasers have an output regulator that the keeps the laser at a constant brightness as the battery drains and also compensates for cold temperatures.

    Of course you're not likely to find this in the cheaper £25.00 to £30.00 5mw green lasers typically sold by astro shops.

    John

  14. You'll find that the dob is easier and smoother to move than a photo tripod. It takes a little practice, but you'll soon get the hang of just nudging the scope enough to keep the target in the field of view.

    The one thing though is to keep the tube balanced so that when it's about at a 60 degree angle and with the tension knob loose the tube stays where you put it or just very slowly moves. If the tube is out of balance you may find that it doesn't move very smoothly in the ALT axis.

    And BTW I consider the 8" dob to be the perfect beginners telescope. It's what I'd recommend if someone asked me.

    As to sneaking it into the house..........you're on your own there.

    John

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