John

I have owned 2 of these but at least 10 years apart !

I picked up the latest one a couple of months ago. It is the 200P Classic model pretty much unused.

I was expecting some stickyness (for want of a better term) on the azimuth axis and when I first lighted the scope, it was there. The scope was useable but frustrating at high power because it was all to easy to apply too much push in azimuth to get it moving, overshoot the target, then do the same coming back the other way !

I tried different tensions on the central nut and bolt but that didn't really help. I then reminded myself of the old "milk carton washer" modification that I had used all those years back with my other 200P dob. 

For this new scope I found that adding a single large washer (about 100mm in diameter and with a 12mm hole in the centre for the bolt) made a noticeable difference in reducing the "sticktion" to a low and acceptable (for me) level while retaining stability in the mount base. I put my milk carton washer between the bottom board and the stock white teflon washer. I then bolted the mount base back together and applied enough torque to the central locking nut to hold things together in a stable manner. 

I think the way this works is that the additional thickness of the DIY washer takes a little of the weight off the 3 teflon pads that are used as the azimuth bearing. Some people find more than one DIY washer is needed but in my case one did the trick. 

I realise that other people use lazy susan type bearings and other approaches and those undoubtedly work for them. Different people have different preferences for ease of movement etc so this is why there is not 100% agreement on the best approach. People find what works for them 🙂

I have found the milk carton washer modification has worked for me 3 times now - I also owned a 10 inch Skywatcher dob a few years back and did the same thing on that - 2 washers needed with that one I recall.  

I have also owned dobs with lazy susan type bearings as standard and those needed some friction adding to the motion to get it to suit my tastes. 

1 hour ago, Bugdozer said:

That’s not necessarily true, though, is it? If an object is very low contrast and dim, we can often see it's there, but not necessarily make out many small details - they may look smudgy and ill defined. Many galaxies are a good example of this. Given that IC434 is relatively large and linear, more cells in your eye picking it up will theoretically make it more detectable than a smaller object of the same surface brightness. 

 

I found seeing IC 434 very, very difficult. I've looked for it lots of times when the sky has been good and I've been using my 12 inch dob, a suitable eyepiece and a good H-beta filter. On the 2 occasions that I have seen it, seeing the darker "bite" out of it that demarks Barnard 33 (the Horsehead) was quite possible. The Horsehead itself is not small.

Even seeing the Flame Nebula can be quite challenging under a less than very dark and transparent sky and you really need to be able to see that quite obviously to have a chance of the more subtle IC 434.

9 minutes ago, IB20 said:

They’ve both been purchased… phew!!

Thank goodness for that !

I was starting to make a case to myself that I really need something that fits in between my 120mm and 130mm refractors ....... 🙄

Here is my report of sighting the Horsehead Nebula from my back yard a few years back. I've done it once since then, again with the 12 inch.

Here is the Sky at Night magazine guidance on seeing this target:

How to see the Horsehead Nebula - BBC Sky at Night Magazine

IC 434, the nebulosity that the Horsehead lies in front of is itself a very challenging visual target. It is described as "a bright strip" quite often but my experience is that it is anything but bright, at least under the conditions that I normally observe under (nornally around bortle 5-ish).

It is possible to see the Horsehead with a small aperture scope - there is at least one member of SGL who has seen it, or perhaps detected it is a better term, with a 100mm refractor.

For me, it is probably the hardest visual target that I have managed to see in my years of observing. 

I love Jeremy Perez's description of this one:

"Really, it's like trying to see a little bit of nothing with a little bit of less than nothing resting over it" 🙂

I've owned my Vixen ED 102mm F/6.5 refractor for longer than I've owned any other scope (16 years) because it is such a useful scope. Such an instrument can deliver really low power views of over 4 degrees in true extent one moment and then 250x high resolution views the next. It's really great for solar observing as well (suitably filtered of course).

Very portable, quick to cool down, easy to mount, compact to store. It's just "win-win-win-win" with such scopes which is why they are so popular. The Vixen F/6.5's are long out of production now but there are a number of other fine alternatives available today, a number of which have already been mentioned in this thread 🙂

6 minutes ago, Franklin said:

..... You could try this on a centered star if your mount tracks.

Polaris is useful if your mount does not track.

My preferred approach is on the right of this pic 🙂

I still use the Baader zoom, just not with a barlow. The Svbony 3-8 zoom cost only a few £'s more than the zoom barlow.

6 minutes ago, Bugdozer said:

So if it has, would I expect to see the usual collimation errors the same as if my mirror was collimated incorrectly? And if it has been knocked wonky, what can I do about it? 

Yes, it will look like the scope is out of collimation. It may well be OK though, if it didn't land on or hit anything too hard. 

Lucky there was a plant pot down there !

Hope all is well with the diagonal.

My lovely Vixen ED102 refractor fell of the mount onto concrete a few years back !

Luckily the damage was restricted to the diagonal and dew shield both of which were fixed. Scopes hitting hard surfaces make a horrible noise though, as do their owners a few seconds later 😬

Nice to see the pics and reports on this.

I ended up going out for family a meal and then to the cinema so I've only just been able to get a scope out. Just 2 moons in a line now with Io having gone into hiding 🙄

Nice details in the NEB though.

9 hours ago, Mr Spock said:

Ordered an FTF2025BCR focuser .....

I have one of those on my 130 TMB/LZOS F/9.2. Lovely focuser 👍

Having looked at the new listing I can't believe the price they have reached though 😬

It might be clearish here if the forecasts are correct.

Thanks for the heads up - I'll take a look later 🙂

41 minutes ago, Franklin said:

The best and cheapest way of filtering out the excessive glare of Venus, to help increase the contrast of subtle features, is to observe the planet in a daytime sky. In an evening sky be very careful if the Sun is above the horizon when searching for Venus, morning apparitions are easiest as you can set your scope tracking the planet whilst still dark and then wait for the Sun to rise. 

Similarly, some of my best views of Jupiter have come when observing it against a sky with plenty of light left in it.

Do you get double images of stars as well ?

Is the effect showing at high and lower magnifications, or just high ?

The fact that they rotate one way and then the other as you travel through focus and back again must be a clue I guess ?

Sorry that you have not had a response in 48 hours - it's not an issue that I have encountered with my dobs to be honest with you.

Another thumbs up for the quality 4 inch refractor from me. I seem to have collected a couple of them over the years and both get well used. 

I've had a nice 45 minute session watching the Great Red Spot traverse Jupiter's meridian. Lovely details around the spot and within the N and S equatorial belts. The GRS hollow in the SEB seemed to have a dark "eyebrow" type feature framing the leading side of the spot in the direction it was traversing the jovian disk. Just to the south of the GRS was a truncated portion of the South Temperate Belt. The STB gave the appearance of being "towed" across the disk by the GRS. An illusion of course but nice anyway 🙂

Lots of cloud about so views were grabbed as they popped through gaps in the cloud layers.

The scope used was my Tak FC100 and 150x seemed to do the trick, magnification-wise.

I don't find filters help much with planetary observing. I have tried quite a few and still do now and then but I quite quickly gravitate back to a filterless view and allowing the eye to get used to the contrast of the planetary features. Amazing how a relatively bland Jupiter can come to life with extra detail after around 30 minutes or so observing. Assuming the clouds give you that long that is ! 🙄

For nebulae at star parties I often use a decent UHC filter to help increase the contrast for the inexperienced observers. M42, M27 and a number of other "showpieces" seem to jump out a bit more with a UHC. An O-III filter can make even more of an impact on receptive targets such as the Veil and Owl nebulae but those can be challenging for the novice observer even with such a filter. 

For clusters and galaxies (eg: M31, M45 etc) it's back to as dark a sky as possible and the well dark-adapted eye to get the best from those. 

23 minutes ago, Stu said:

Popped the FS-60Q out for a while and got some decent views of Jupiter, then I detected GRS coming round the corner and thought it worth popping the FC100DC out.

Very fine views, hopefully will get a chance to see it when it transits later on.

 

Same going on here @Stu 😃

GRS is well on the disk now. 

FC100-DL with the rather good Svbony 3-8 zoom on setting 6 so 150x. Straight from the house and steady viewing. Nice 🙂

48 minutes ago, Franklin said:

Guess I'll have to make do with this ED102S F9 from the same year, I'm not complaining!

 

Lovely !

2003 must have been the last year they produced the ED102S and the ED102SS ?

Then I think they pulled them to move to a new eco-glass leading eventually to the ED103 F/7.7 

The maksutov design that I've used that has produced the nearest to "refractor-like" views of double stars was a maksutov-newtonian. These have a smaller secondary size compared to the maksutov-cassegrain although the tube length is longer. The cool down time on that (a 152mm aperture) was quite long compared with a refractor though.

I know which one would win the "shows the whole of the Veil nebula ?" category 🙂

Epsilon Lyrae has separations of 2.2 and 2.8 arc seconds between the two pairs. Theoretically an 80mm scope should be able to resolve to around 1.5 arc seconds but this does assume perfect optics and conditions. In reality neither are encountered that often !

I'm sure that I have read of folks splitting the double double with ST80's but the optical quality of these fast F/5 achromats can vary. 

Were other folks with similar apertures getting the split at that time ? Seeing conditions can make things tough and scrub a lot off the theoretical optical performance.

I have a sense of deja vue about this one because I managed to spot a previous dropped ISS toolbag back in 2009, with binoculars.

But we get another chance it seems !:

Astronauts dropped a tool bag during a spacewalk, and you can see it | Space

It won't stay in orbit for long so time is of the essence !

42 minutes ago, bosun21 said:

Ed Ting bought a blue Takahashi and after a month or two it drove him nuts. He ended up getting it repainted to the standard Takahashi colours.

Tak switched to the blue with the 2nd run of the FC100-DL's. Mine is from the 1st run so it's black.

Personally I prefer the black but I guess I am biased 🙄

I'm guessing that the scope is your 100mm F/5.8.

Comet Lemmon should be visible if your skies are dark enough. It is currently listed as magnitude 6.2 and has just moved into Aquila.

Early evening is best, as soon as it's dark.