Louis D

1 hour ago, tooth_dr said:

Funny I went out a few months ago to a darker site, and of course forgot to put the memory card back into my camera after clearing it earlier that day.  I had a rummage through my camera bag and found an old 1/2 GB card, and was delighted.  That was soon short-lived when I discovered with my 36MP Nikon it held just 8 photos.

Yep, along with fully charged batteries, I always keep a few extra memory cards in my camera bag.  I've even sold some at fairs to other old geezers who see my camera bag and ask if I could sell them a spare because they left theirs home.

21 hours ago, markleton said:

I'm very happy with both eyepieces and am considering a high magnification 3 or 4.5mm eyepiece in the 52 series from ES.

Unless your Dob is on an equatorial platform, you are going to want at least a 65 degree AFOV for any eyepiece yielding powers above 200x for manual tracking purposes.  I have a Pentax XW 3.5mm for this purpose that works really well.

Try out your existing 2.5x Barlow with your eyepieces to see if you like the combinations.  Going to a 52 degree eyepiece at high power after using that 92 degree eyepiece will feel almost suffocating.

The Morpheus 4.5mm might be another option.  It has a bit of EOFB from what I've read, but is otherwise very nice.

I only buy local from Fry's because they monitor their supply chain.  I've gotten too many counterfeit cards from online sellers to ever go back.  Hopefully you have a local electronics discounter there to buy from as well.

1 hour ago, sputniksteve said:

But for now, I'm looking at something small an portable, but powerful enough for good views and maybe some basic astrophotography. Thinking of the 127 Maks - SW or Celestron - or maybe a C6 in some guise or other if I can persuade the boss that it's money well spent! 

YeeHaw and Howdy from Texas! 🤠

The 127 Maks make good travel scopes because they don't take up much space and hold collimation extremely well.  If you check the classifieds, you can probably find one used for a fraction of the new price in excellent condition.

The GSO/Revelation Plossl 32mm is quite good as well.  However, I've never looked through a Vixen NPL, so it might be better as @John suggests above.  The BST Starguider 25mm is good over the inner 30 degrees, gradually degrading to the edges.  The Meade HD-60 25mm is better, but discontinued and more expensive.

If you could double your budget, the 35mm Aero ED is quite nice and takes advantage of your 2" focuser to max out your true field of view.

I bought a cheap red dot finder off ebay for a small scope.  It is compact and can be made very bright for daytime usage.  After all, they started out as gun sights.  Make sure to get the correct foot/shoe for your mounting needs.

There's a vendor on CN Classifieds selling 3D printed camera flash shoe to Vixen finder mount adapters:

17 hours ago, Don Pensack said:

It's been done for over a century.  However, rarely on a scope > 6" in size.

I remember the Keck scopes covering their apertures with solar filter film when a solar eclipse passed over Hawaii some years back.  Can you imagine one of those beasts doing solar projection? 😱

Assuming your f/4.7 scope is a Newtonian, I'd recommend getting a coma corrector.  If you don't have deep pockets, the Revelation CC works well once you put a 25mm M48 spacer ring between the optics section and the eyepiece holder.  It will improve the edge performance of your Panaview 38mm by flattening the field and removing most of the coma.  Even your Nirvanas will have improved edge performance.

I'd go with a BST Starguider/HD-60/XCel LX over a Tele Vue Plossl except possibly at 18mm and 25mm in an f/4.7 scope.

4 hours ago, merlin100 said:

"Watch the birdie"! 🤣. Sorry, couldn't resist. 😉

You jest, but lots of folks swear by these observing hoods:

1 hour ago, Dr Strange said:

Sadly I am in Bortle 8/9 skies so star hopping isn't really an option for me unless I have a lot of time.

That is pretty brutal.  I'm around Bortle 5/6 depending on the direction from my backyard.  It used to be much better before tens of thousands of people, two toll roads, and lots of strips malls opened up nearby.

2 hours ago, Dr Strange said:

In addition I don't understand what you are saying about how GOTO mounts are not as smooth or easily controlled. I don't look in the eyepiece as the mount is moving to a new object so smoothness there doesn't make sense. When I have (just to see what was going on and in the field as it moved) the motions are smooth. And the tracking is not noticeable at all it is also very smooth. And that is not with a high end mount. That is with a Celestron or Skywatcher mount. Please help me understand what you mean by things are not smooth?

Turn off the GOTO and unplug the power.  Are these GOTO mounts as smooth in manual motion as your DM-6?  What I was attempting to say was if you start with a superb manual mount and then add encoders and motors, it is equally adept in any of the three modes, full manual, DSC-only, or full-GOTO.  By full GOTO, I was thinking of the AZ-GTi mount you like to recommend.  How does it compare in manual usage to a DSV-1 or similar for instance?  Does it have decently variable clutches on both axes with roller bearings to allow smooth manual tracking at high powers?  If it does, I might think about getting one because it would be nice to have GOTO available occasionally without having to swap mounts entirely.

2 hours ago, Don Pensack said:

Using a newtonian for projection of the solar disc works OK with simple eyepieces like Ramsdens or Huygens as long as they are glass and the housings metal.

Good luck finding such an eyepiece.  They were common in the '60s when I got started, but the ones out there now are usually plastic.

I just wouldn't want that amount of concentrated sunlight on my secondary mirror.  I've got to think it would get mighty hot which can't be good for the coatings or the holder.  The actual glass of the mirror would probably be okay.

2 hours ago, JOC said:

No, I don't think so, in fact I don't think there is any scope out there size wise that makes stars look like discs (the only exception being Sirius which the atmosphere often renders as a monster raving party star light show).

Betelgeuse has been resolved by several large observatory telescopes such as the  European Southern Observatory's Very Large Telescope as in the images below highlighted on APOD earlier this year.

And then there's push-to with DSCs on a manual mount.  Sometimes, I'll fire up the DSCs on my Dob when I'm having a difficult time locating a challenging object.  Since I don't generally look for challenge objects, a purely manual mount works well enough 98% of the time.

Full GOTO is handy if you're sharing the view, but so is plain old equatorial tracking.

Most full GOTO mounts are nowhere near as smooth and easily controlled in manual mode as an equally priced manual mount.  Of course, there are the high end mounts that start with a fine manual mount and then add DSCs and motors to achieve full GOTO allowing you to have the best of all worlds depending on your mood on a given night.

On 14/06/2020 at 19:28, PembrokeSteve said:

1. TS Optics Photoline 90mm f6.6 FPL3 Triplet

Well, I use mine visually, and it's quite nice.  Star points are nice and tight and pretty much color free at best focus.  Airy disks are apparent on one side of focus, but not so much the other.  Is it a huge step up from my AT72ED (FPL-51 doublet)?  No, it is more incremental.  The big step up was from my ST80 to the AT72ED.  Is it as color free as a Newtonian?  No, but the tighter star images make up for it visually.

Photographically?  I think your money might be best spent elsewhere as others above have suggested.  Visually, moving from ED to APO wasn't nearly the game changer I had expected.  It's still not at the color free level of a Newtonian, but there's no central obstruction.

2 hours ago, Don Pensack said:

As for the sun, one poster described leaving his big dob on the porch when he went to bed.  The morning sunlight reflected off the mirror on the eave of his house and set the house on fire.

Fortunately, very little damage was done.  But if you ask if sunlight can melt a Barlow or eyepiece?  Yes, it can.

I read about another person allowing the Dob's mirror to dry in the sun after washing and rinsing.  The angle was such that the sun was focused on the eaves and started to scorch it.

As for the OP, this seems to point to using a Newt to project a solar image which is not a good idea.

On 14/06/2020 at 11:37, pjsmith_6198 said:

The height of the rocker box depends on the balance point of the telescope.

However, back heavy scopes end up with short height rocker boxes, an extremely large swing in altitude height, super awkward usage at low altitudes, and a particular sensitivity to heavy eyepieces due to the long moment arm magnifying their effect on balance.  I find it much better to weight the top end to counteract such back-heaviness to allow for a balance point more in the middle of the tube and thus a taller rocker box.  If the weight is on the opposite side from the focuser, it also makes the scope less sensitive to not being completely level in azimuth when used with heavy eyepieces.

There was a recent APOD image of Thor's Helmet where it's obvious that images of different resolutions and sizes were successfully combined for an overall pleasing result:

I have the 9mm Morpheus and find it to be nearly the equal of my 10mm Delos, just with a wider AFOV.

The 14mm is nice, but has some field curvature and astigmatism in the last 15% of the field.

My understanding is that the 12.5mm, which I don't have, is somewhere in between performance wise.

For widest field, but not the best correction at f/5, I would go with the 35mm Aero ED.  It nearly maxes out the field of view possible in a 2" barrel.

For best correction at a reasonable price, I would go with the 30mm APM Ultra Flat Field (or Altair UFF).  It has nearly the same true field as the 35mm Panoptic with more magnification, less field curvature, and less distortion.

The 31mm Luminos has SAEP and EOFB to deal with.

The SWAN eyepieces won't do well at f/5. The Aero EDs do better for similar money.

The 34mm ES-68 is decent, but is regarded as the weakest of all the ES-68s.

The zoom might not be such a bad idea with kids.  I've read that the Celestron and SkyWatcher versions are from the same Chinese manufacturer, so buy based on price if that is the case.

I have a sub-$20 Zhumell OIII filter which acts more like a light pollution filter than a true OIII filter like my 90s vintage Lumicon.  Price does make a difference.

5 hours ago, malc-c said:

If the scope was purchased via a website then you als have additional rights under the distant selling regulations and can return it for any reason for a full refund provided you notify the supplier of the fault or reason (it can be any reason, even if you don't like the colour) within a set number of days (I'm not a legal expert, but believe its 14 days).  The only issue here is if the supplier is not based in the UK

I'm assuming that's a UK law rather than an EU "law"?  The OP's location is Alicante which is apparently in Spain.  Who knows where it was purchased from.

I'm curious to know what brand of Dob that is.  The main two manufacturers are Synta (SW) and GSO (Revelation) with JOC possibly making Bresser.

I was out with the 8" Dob last night and tried the Meade MWA 26mm again with and without the GSO coma corrector.  It turns out there's surprisingly little difference other than the fuzzy true field stop without the CC that I mentioned above.  It's so difficult to use the outer field, that any significant difference is just too difficult to tease out.  I would say the biggest benefit of the CC was the field flattening effect.  Even with the CC, there is still slight field curvature in the MWA.

CC or not, it was tiresome trying to keep the blackouts at bay while scanning star fields, even at the "easy view" distance with eyeglasses.  I could always see an incipient shadow ready to rear its ugly head as my head/eyepiece alignment varied during scanning.  It displays a pleasingly sharp and false-color free view in the central region, but the always imminent SAEP is really a bummer.