(Slightly delayed) First Light report on 14 Inch Dob

The American humourist Will Rogers once observed that there are 3 kinds of men: Those who learn by reading, the few who learn by observation and the rest who have to pee on the electric fence for themselves. I’m joining the third category, as, against the advice of just about everyone I’ve discussed it with I’ve decided to get myself a large(ish) Dob.

Although in the last nine months or so, I’ve become interested in Astrophotography I also really enjoy visual observing, and especially hunting for objects. When I saw a 14 inch’er on Astrobuysell that was relatively portable there was only so long I could avoid temptation. Gotta have something to do whilst taking subs…

I’ve managed one short session between the clouds last week, which was a good reminder of the tribulations of getting to know a new scope but also a promise of fun to come. I could not find anywhere convenient to mount my Quickfinder- I put it too close to the eyepiece and managed at one point to head-butt it clean onto the grass. I also found that the 35mm Eyepiece that came with the scope gives truly horrible views (it may have a future career as a paperweight) and that the Azimuth adjustment is pretty sticky- especially near the zenith. All of these things are going to need some sorting. Attempts to observe M42 and M31 were both scuppered by banks of cloud rolling it at the wrong moment, but just as the frustration levels were rising I got M81 in the eyepiece and saw for the first time with my own eyes detail beyond the galaxy core. Next up was M51 and here I could see both cores quite clearly and some of the material that joins them. In five minutes I had swung from irritation to elation and with the clouds now rolling in I went for the Leo triplet, something I just haven’t been able to see from my location before. Just in time I found them- no detail, but the shapes quite easy to see even without averted vision. That was pretty much it, as the clouds rolled over and haven’t really parted since, but enough that I’m very excited about the next clear night…

PS- I’d like to apologise to everyone for invoking “The Curse of the New Scope” and ruining the weather for a few weeks.

8 Responses

  1. Rob,
    Has it got a spot in the centre of the mirror? That also helps a lot. If not and you can get the mirror out, worth considering adding one. (with a felt-tip pen)

    1. Thanks Roger- yes it has a ring in the centre of the mirror and I’ve got a laser collimator. After Lee’s masterclass last year I’m pretty confident with collimation- the 26mm worked well in it, it was just the wider ep that looked awful. I’m looking forward to having another go- just wish these flippin’ clouds would get it of the way!

      1. Hi Andy- it’s an Orion USA intelliscope. The previous owner was an amateur telescope maker who had bought it for the electronics and sold it on as a manual telescope. The focal ratio is 4.6.

  2. Don’t be so negative on your 14 inch scope! I am sure it will deliver superb views and, in any case, most of the negatives associated with large scopes are rather about trade-offs and then it is a matter of personal taste. Many people will say bigger is better regardless of sky quality and if you have that desire for a large scope than can only be sorted by getting one, as o did, then you must get one!
    Now also do not write off the 35mm eyepiece. Let Lee or myself take a look first. The most likely problem is coma and this is the plague of large dobs. Both Damian and I purchased Televue Paracorr coma correctors and we would swear by them. Basically a large dog is like the uncorrected Hubble Space Telescope when it was first launched. It needs the correcting optics to function properly and once you have them then……wow! When we bought the Paracorr at that time Televue were the only people producing coma correctors for dobs but now there are multiple firms doing them and some are a lot cheaper but do some research before buying as not all will focus on your dob. This is because a coma corrector requires extra in focus which is usually not available on dobs or Newtonian telescopes. The Paracorr overcomes this by incorporating a 15% Barlow into the design which sends the focus point back out again. Once you sort that out your 35mm may perform well – in general 35mm is a brilliant compliment to a large dob together with something around 13-17mm and another around 7mm. Second hand dobs always have things to sort out but usually deliver once sorted and life would not be fun without a bit of a project!
    Andy

    1. Thanks for the encouragement Andy- reading the report back it may sound a little more negative than I’d intended- certainly by the end of the session my frustration was more with the conditions than the scope and I can’t wait for clear skies and a chance to spend some proper time with the scope.

      Thanks also for the offer to have a look at the EP for me- I’ll bring the setup along to the next club meeting when we have a clear night. The issue with the view was strange- there was a lot of Coma, which I’d half expected, but I also couldn’t focus on objects in the centre of the field. As I moved through the point of focus the stars in the centre would not resolve into a sharp point. I wondered about collimation, but I put a 26mm EP in, and it was sharp as a tack. Ken Crichton has lent me what seems a much higher quality wide EP so it’ll be interesting to have a play with that!

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