Louis D

12 hours ago, TareqPhoto said:

1. My main big plan is to buy a Takahashi FSQ brand new, not many will sell this

Two FSQs went up for sale on CN classifieds for $4800 each yesterday.

I just checked on a bunch of the low cost eyepiece kits, and they all come with one or more eyepieces at or below 8mm in focal length in a 4 element design.  The eye relief on such eyepieces makes them incredibly uncomfortable to use.  There's a reason Tele Vue stops their Plossl line at 8mm and discontinued their 7.4mm version.  Even at 8mm, most folks report a great dislike for that eyepiece due to lack of eye relief.  I also notice one kit states that their 32mm Plossl only has a 44 degree AFOV instead of the normal 50 to 52 degrees.  One has to wonder where they found a 32mm Plossl with only a 44 degree AFOV?  I've never seen one sold separately.  The whole point of a 32mm Plossl is to maximize the TFOV available in a 1.25" barrel, and that eyepiece would fail to fulfill that most basic role.  The Barlows packaged with these kits appear to be the most basic type that noticeably degrade the image.  I gifted just such a Barlow to a buddy starting out, and he returned it back to me within 6 months noting how poor it was.  If you really want to try a kit, I'd watch the classifieds for them since they don't hold their value very well.

I'm not sure what eyepieces you have right now.  However, I'd recommend the Revelation Plossls since they're made by GSO, are very good, and low cost.  I have the 32mm GSO Plossl, and it is fantastic.  I'd skip the 25mm Plossl as it is too close in power to the 32mm and go with the 20mm next.  I think I recall you having a 15mm Plossl already, so next would be a 10mm to 12mm.  I'd switch to BST Starguiders to get decent eye relief and a wider field of view in this range.  The 12mm is very good while the 8mm and 5mm are excellent.  With a 5/8/12/15/20/32 set, you probably wouldn't really need a barlow.  As far as filters go, watch the classifieds.  I've seen quite a number of 6 or 7 piece sets go for $20 or so recently.

It really depends what you want.  Do you want an upgrade on what you already have?  Do you want to fill in gaps in power?

If you're sitting on a pile of cash, I'd wait to see what gets dumped on the used market in the next few weeks/months as folks start to run up against financial difficulties.  I picked up a lot of great deals between 2008 and 2013 during the Great Recession and the period immediately following it.

1 hour ago, Shimrod said:

 

So I made a decision and the new scope arrives on Monday. I went for the Skywatcher ED80 DS PRo in the end, but I've bought a Baader Steeltrack Diamond RT to upgrade the focuser. I decided that some of the other telescopes were just a little too wide for me - the ED80 gives me a good compromise on portability and use for visual and photography.

Looks good.  I've found the 600mm FL on my TS-Optics Photoline 90mm f/6.6 FPL53 Triplet APO to be a nice sweet spot between my 400mm class refractors and my 1200mm Dob.

24 minutes ago, vlaiv said:

Not only that - what happens if a person is sitting in the chair - observing. It could be very awkward to have mount push the scope against you - potentially knocking you off the chair or something.

Rapid movement is an option - but it should come with some sort of audio warning - "You are about to be flipped! Do you want to continue?"

I hadn't thought of getting hit, or worse, having an eyepiece jammed into your eye socket. 😵 Think about the liability issues for the manufacturer.

I'm surprised it can't deal with Dobson's hole at all.  I would have expected it to issue a bunch of rapid AZ motions to eventually get a 180 degree rotation.  Is it because it realizes it can't keep the object centered well enough during the contortions so it gives up entirely?

42 minutes ago, banjaxed said:

Thanks for the comments. The reason I was a bit reluctant to try and clean it was the Meade manual clearly warned not to try it. Normally I would just get on with it as I have always been very practical and will try anything within reason. Cleaning all the cell lenses is far more tricky so they will be left alone ( for now) 😀

 

Yeah, I wouldn't open up the lens cell because trying to get all the spacings and orientations/rotations correct again could be problematic, even more so in a collimateable triplet.

Yeah, 3.5mm is really pushing things, even under steady Texas skies.  I rarely go beyond using a 5mm eyepiece on most nights.  I have the TV Barlow, and while it is good, it will slightly degrade the image compared to using a dedicated 3.5mm eyepiece like a Delos or Pentax XW.

4 hours ago, merlin100 said:

I've noticed that various manufacturers seem to produce complete eye piece kits for their scopes. Whilst I want to build up a small collection of usable eye pieces, would buying a complete kit with a case be a waste of money?  I'm thinking it maybe already duplicating what I already have or maybe of lower quality, etc...

I would skip the low end kits.  They include lower end eyepieces and filters you probably won't use.

Meade used to sell all six HD-60s in a case.  I have it and can heartily recommend it.

You could purchase all seven BST Starguiders from FLO and get a 20% discount on each and then buy a small case for them with pick and pluck foam.

At the higher end, you could get a set of Stellarview Optimus 100 degree eyepieces with case.  😉  These are the same as the APM HDC-XWA offerings if you want to local to Europe, just without the customized case.

I tend to use a variety of eyepieces from a variety of manufacturers and store them vertically in a Pelican style case.

3 hours ago, banjaxed said:

Thank you John for your very clear instructions, I managed to remove the dew shield ( eventually) and removed the lens cell by undoing the 3 screws, then used my blower to remove all the bits and bobs from the lens and gave it a gentle clean. It is a lot better now but it probably would benefit from a good cleaning of all the cels but I think it would be better to leave it as it is, I don’t really want to go that far. Thanks again to all for your help.

Having done all that successfully, I'll bet your confidence level has shot way up. 😁

3 hours ago, Second Time Around said:

Many thanks, Louis!

Do these zooms take a Dioptrx? I see there's a photographic thread, is it between 41 and 44mm?  If it's the same as the M43 on my Baader zoom a Dioptrx will fit, although an O ring or elastic band on the thread will help.

You'll like it.  What's also really nice about them is the silky smooth zoom action.  There's no stiffness in it like so many other zooms.

Once the eye cup is completely removed by unscrewing it counterclockwise after the eyecup is all the way down (it retracts when rotating counterclockwise), a 37mm thread is revealed that is 6mm high with 2mm unthreaded above that.  I was able to thread a 37mm step ring onto it perfectly.  Thus, if you can locate a 43mm to 37mm step down ring, you should be able to attach a Dioptrx to it.

I really like my Celestron Regal and Olivon spotting scope eyepieces.  Once the eye cup is screwed off, there is plenty of eye relief for eyeglasses and the top does not rotate during zooming.  They vary from about 44 degrees at 24mm to 63 degrees at 8mm AFOV.  The field stop is sharpest toward the central part of the zoom range and gets a bit fuzzy at either end.  Edge correction is pretty decent.  It's included in my eyepiece field of view images at 8mm, 12mm, and 24mm.  The only tricky part is finding them since they are not sold individually anymore.  I watched ebay and the classifieds to pick up mine from spotting scope owners who didn't want them but wanted to recoup some of their investment.

Avoid the 1.25" WO diagonal.  It vignettes widest field eyepieces because of thick ring in the eyepiece receiver.  I've got one and can confirm this.  I wouldn't have bought it if I had known about this issue ahead of time.

As far as 2" diagonals go, I like the GSO dielectric so much that I have 3 versions of it.  One is GSO, one is TPO, and one is ScopeStuff branded.  One is quartz, the rest are regular glass.  I can't say the quartz is any better, but it was the same price as the others used (about $70 each).  They're branded Revelation in the UK.  I have never been disappointed by any GSO gear.  Their 2" ED 2x barlow is excellent, their 32mm Plossl is excellent, and their coma corrector is excellent.

Generally, if you can remove the dew shield by either sliding it off or unscrewing it, the screws holding the lens cell in place should become visible.  The trick is figuring out how the dew shield is attached.  For some, you need to unscrew the tube part from the rear reducer part by grabbing the two and twisting them gently apart.  Others, the entire tube and reducer unscrew from the main OTA tube.  Some are just slip fit and need wiggled off as a whole with some gentle back and forth twisting.  Do some online research to see if you can ascertain how yours is attached.

7 hours ago, tjs247 said:

I'll try different eye pieces tonight. It's in the middle of the day so best I could do is a rough diagram. 

 

Interesting that the ghosts coincide with one of the secondary spider vanes' diffraction spikes' axes.  Perhaps the eyepiece is somehow picking up the bright diffraction spike and imaging it.  Try rotating your eye and eyepiece each relative to the focuser to see if anything changes.  Ideally, I'd say rotate the OTA and see if the ghosts follow it, but that would be difficult without rotating rings.  You could put an edge-on ruler across the front of the scope at a different angle from the vanes to see if that introduces a new diffraction spike and more ghosting.

21 minutes ago, tjs247 said:

Well I've been having issues with my telescope.  I was looking at venus and I see like faint copies of Venus next to each other with actual Venus at the center.  I'm sure my scope.was collimated to. The mirror doesn't look quite good either, very dusty and a couple of smears somehow. So might just need a clean.

Have you tried other eyepieces to see if the ghosting changes or goes away?

1 hour ago, CLOUD90 said:

 Hi all are the Celestron X-Cel LX Series Eyepieces any good for my 250p sw Dobson ? 

Probably, though multiple people have noted some black debris on the internal lens surfaces (QC issue?).  The Meade HD-60s are reportedly the same optically, but have not had any such reports.  I have a set of both the HD-60s and the AT Paradigms (BST Starguiders), and both are good.  I've reviewed them here.  However, that was at f/6, not f/4.7 as with your scope.  They might perform a bit worse, especially the longer focal lengths, in your scope.

2 hours ago, fozzybear said:

Found the document that might help you

Andy

SWN1507eq3_Skywatcher_Crayfor-Auszug_justieren.pdf 909.15 kB · 2 downloads

Yes, there it is, the centered tension screw I mentioned.  I just couldn't see it in the photo due to the lack of any reflections off of it.

40 minutes ago, johninderby said:

Do yourself a favour and try a Berlebach tripod and it will change your perception of what is a good tripod is. They really are that good. 👍🏻👍🏻👍🏻

Are the spike tips retractable for use on concrete?  Is the leg angle variable or fixed based on chain length?  Is there a variable height center post available?  They don't seem all that different from a surveyor tripod.  I like to sit at a fixed height so my feet are on the ground and then adjust the telescope height to suit for wherever it's aimed at.  Typically, I start with the height comfortable for about 35 degrees altitude by adjusting the leg spread angle and then raise the center post to raise the eyepiece if the altitude of an object becomes too high that causes the eyepiece to become too low to look into comfortably.  Since the minimum height is only 39 inches on that Berlebach tripod, I have no idea how I'd get it down low enough to use sitting without new chains, assuming the leg pivot points would allow for that spread angle.

Here's the setup I use:

7 hours ago, johninderby said:

The Berlebach tripod is more stable and handles vibration better than a steel tripod. Once you’ve used a good wooden tripod you won’t settle for steel. Wood is simply better for telescope tripods.

Notice how many owners of higher end scopes use a wooden tripod.

I've had good luck putting Sorbothane pads under each foot of my aluminum tripods to dampen settling time from 3 to 5 seconds to 1/2 second.  Perhaps wood might improve on that, but it's good enough for me.  I find non-adjustable tripods really annoying for astro observing.  You can't vary the leg spread, you can't increase or decrease the mount height, etc.  That's why I went with heavy duty photo tripods with high load capacities.

I would guess based on previous focuser experience that those two set/grub screws directly centered over the pinion axle on the bottom plate determine the tension.  Typically, there's a single one centered near that silver locking screw, but yours appears to have two.  I would also guess they have to have equal tension, so after backing them off with an allen key/hex wrench, make sure to tighten them in small increments and equally to suit your liking in tension.

20 hours ago, JeremyS said:

Maybe it's time for somebody to buy a TeleVue Apollo 11 eyepiece  - before they become expensive

🙂

Based on this list from CN, Stef from the UK (Bury St Edmunds, Suffolk, UK) bought one:

#005 – Stewc14 – Pueblo West, CO
#014 – Joe47 – Tucson, AZ
#018 – Starman 1 – Los Angeles, CA

#020 – J A Volk – Monrovia, CA
#026 – RichF – Mid Atlantic, USA
#036 – Ac2aj – Bayville, NY
#047 – Sanbai – Baton Rouge, LA
#049 – Vanc0051 – Minneapolis, MN
#061 – fmasa – Osaka Japan
#074 – Roragi – Madrid, Spain
#075 – Tamiji Homma – California, USA
#080 – Dave Bush – Parker, CO
#084 – Daryel Stager – Spring Valley, CA
#086 – Starvagabond – Verona, Italy
#118 – Stef – Suffolk, UK
#119 – TomDey – Springwater, NY
#151 – Esso2112 – Magnolia, TX
#165 – Jeff Struve – Iowa, USA
#179 – Ares53405 – Racine County, WI
#183 – Peter A. – Simi Valley, CA
#187 – AstrOceanOmy – Sultanate of Oman

#198 – Tamiji Homma – California, USA (yes, a second one!)
#222 – Stewc14 – Pueblo West, CO

Seek him out and ask him to join SGL and share his thoughts on this new eyepiece.

Or try nylon or teflon strips if you can find some thin enough to fit.  You could also try shimming with strips of plastic milk jugs.  Remove the focuser from the main telescope tube first before you start playing around with it, though.

3 hours ago, davekelley said:

OMG you make that sound really bad!  I haven't been able to test it out on the night sky I was just testing the ability to focus in the daytime.  I had a look through a 32mm plossl and I thought the Nirvanah was 100% nicer.....

 

 

Don't worry about it.  I've done the same with my 127 Mak and the results look spectacular to the eye.  It's way better than operating at 3x with a Barlow element to reach focus which works out to 4500mm, unless you're trying to go for planetary views with 32mm Plossls (11mm equivalent), then it's fine.

38 minutes ago, davekelley said:

I put one of my Nirvanah 16mm ep's into the binoviewer, just to test if I can get focus without the barlow and very easily can, not just focus but a very comfortable amount of eye relief and a really pleasing wide fov, which will be more pleasing when I've got a 2nd Nirvanah and I can use both eyes.  I am certainly going to purchase a 2nd Nirvanah.  The barrel of the ep is long and seems to sit a bit proud of the holder but it doesn't seem to be an issue.  I am wondering what the effective focal length/power is that I am working with?  The 127mak is 1500ml and I use a tak prism diagonal and I think the 16mm ep sits about 5mm or so proud of the holder.  Overall though so far, very exciting.  I will post back after I try it out properly with two eyes.  

Clear skies

Dave.

You're probably operating up around 2000mm to 2200mm or so for focal length with the binoviewers in the path, or about 1.4x nominal.  You're also losing some clear aperture as well as adding some spherical aberration and increasing the percentage of central obstruction by diameter.