Louis D

4 minutes ago, Space Cowboy said:

Scope and cow weren't in the same field I must add. 😉 Yes I'm a farmer, hence the name 🙂 

Generally in the US at least, if you consider yourself a cowboy, you're a rancher rather than a farmer.  Ranchers are generally regarded as way hotter than farmers, BTW, thanks to the whole cowboy mystique (cowboy hats, boots, rodeos, rugged appearance, etc.).

At higher powers, I'm generally looking at smaller objects, and 70 to 78 degree AFOVs seem plenty wide enough for my non-tracking observing of such objects.

18 minutes ago, Gibbous Mars said:

Thanks for the great advice! I just have a quick update - and new query! I've taken the advice above and bought a second hand HEQ5 Pro GoTo Mount which should future proof any future visual and AP aspirations. However, I just need to sort a power supply for the mount. 

Any advice or recommendations for a mains-fed power supply for the HEQ5 mount? I mainly plan to observe from my garden so I can power it from a mains and I understand it needs a ~12V power supply. 

I was thinking something along these lines should do the trick but any advise would be appreciated!

https://www.amazon.co.uk/dp/B0BLHGZ4QP/?coliid=I2DZJTHMYLTU2A&colid=174HHE3IM73KU&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

https://www.amazon.co.uk/dp/B08NCLCWFB/?coliid=I1EG3L6Q5AYQEX&colid=174HHE3IM73KU&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

  

A lot of these cheap, variable voltage power supplies are not well regulated.  Their voltage can vary while under load, not supply enough amperage, introduce electrical noise into the line by being a switched power supply, burn out prematurely due to cheap components, etc.  You just need 2A at 12V, so find a quality 12V transformer type power supply rated for at least 2A with the proper connector, and you should be good to go.

I'd probably like a 22mm to 25mm Apollo to replace the 22mm NT4 which needs better eye relief and less SAEP.  I'd pay up to $600 for one, possibly more, if absolutely perfectly corrected, flat of field, 18mm of usable eye relief, and no SAEP at all.

I'm good with the ES-12 and ES-17, so no desires for Apollos there.  I can always Barlow these two to easily get to 8.5mm and 6mm focal lengths.  I've done this, but I have never felt like I wanted to use that amount of FOV at those focal lengths.

Don't be afraid to push up the magnification into the 75x to 100x range to see if smaller DSOs like M57 become easier to pick out.  At 33x it's basically stellar in appearance.

16 hours ago, Merlin said:

The reason for why I use reduced specs lenses is because I have double-vision. Without the lenses inserted in the eyepiece cups, I wouldn’t be able to use the binoviewer and also some of the binoculars, where  eye relief is short.

I could see that being an issue.

Over a couple of decades ago, I recall reading about some who had fresh prescription blanks cut and mounted into filter housings by his optician to attach to the bottom of eyepieces.  The poster claimed they worked well to correct astigmatism in his eye, but optical designers claimed that it wouldn't work if they were used before the eyepiece rather than after.

10 hours ago, Don Pensack said:

And if they removed a lot of the weight.

12mm ES 92--1017g

11mm TeleVue Apollo 11 85°--612g, or 405g lighter, or about 0.9 lbs!

Yes, 92° is wider than 85°, but not by that much.

Both are usable with glasses.

 

And the TV Apollo 11mm would be a lot more popular if they had cut about $800 off the cost.  I'm not sure how well it would have sold without the caché of being a limited edition eyepiece.

I vaguely recall Denis offering an astro version of a Zeiss microscope binoviewer that almost entirely uses mirrors, so it might not have the differential dimming effects of a prism based BV.  It still uses a prism beamsplitter, so differential polarization may be unavoidable even with it.

4 hours ago, JOC said:

IME I've never had any problems viewing whilst wearing glasses, but I do find that I get on perfectly OK if I just take my specs off.

Lucky you.  My 2+ diopters of astigmatism renders bright stars as spikes and dim stars simply wink out of existence without my eyeglasses.  It's not until I get down to about 1mm exit pupils that the astigmatism effects fade, but never quite disappear.

4 hours ago, Merlin said:

A thing you can try Louis is to do what I did. Get a cheap pair of specs and take the lenses out. 

Next, cut the lenses down to fit into eyepiece cups. I hold them in with a bit of blue tack.

Before reducing the size of the lenses, put a small disc of easy to remove sticky paper on each side of each lens to protect the surfaces while you saw and file the rest of the lenses away.

I would probably just buy a Tele Vue Dioptrx first, even if it doesn't fit every eyepiece I own.

2 hours ago, LukeSkywatcher said:

I've never had an issue with viewing through a window. The only thing to be mindful of is that the heating in that room is switched off.

You probably don't want to view through vintage glass, though.  My daughter's house has many original 120 year old window panes.  Even to the naked eye, they make the outside world look a bit like funhouse mirrors.  Glass flows due to gravity and ends up with waviness over the decades.

I have a 3x Barlow that I've used maybe 2 or 3 times in the past 25 years.  However, I have a multitude of 2x Barlows that I regularly use.  I would definitely recommend a 2x over a 3x.

20 minutes ago, John said:

The only NT4 that I have owned is the 22mm which is reputedly the easiest Nagler for glasses wearers to get on with.

Correct.  It is usable thanks to it's SAEP being the mildest of the line.

21 minutes ago, John said:

Having read many accounts of experiences of eyepieces from folks who wear glasses when observing I have come to the conclusion that the experiences of glasses wearers vs non glasses wearers is very often going to be different where eyepieces are concerned.  

No doubt.  Eyepieces that appeal to non-eyeglass wearers don't generally appeal to eyeglass wearers and vice-versa.  There are those with long eye relief and adjustable eye guards which seem to appeal to both.

As an example of the first case, having looked through a 21mm Ethos at a star party while wearing eyeglasses, I was very much "Meh" about it.  If I could see 70 degrees AFOV, I'd be surprised.  I took my glasses off, put my eye socket against the eye cup, and was greeted with loads of astigmatism (at least with bright stars) across the 100 degree field.  All of the faint stars disappeared thanks to my eye astigmatism.  I was completely underwhelmed by it.  I'm sure if I didn't have 2+ diopters of astigmatism, I'd have been more impressed by it.

Perhaps if ES added an adjustable eye guard to the ES-92 line, it would have more general appeal.

34 minutes ago, John said:

I used the 14mm Delos and the 13mm Ethos tonight. Both really nice but I find the Ethos view the most engaging. I don't wear glasses when observing though.

I know you briefly had the 12mm ES-92.  How did the engagement differ between it and the 13mm Ethos?  I vaguely recall you had difficulty holding the exit pupil of the ES-92.

Wearing glasses, the ES-92s feel to me like the Delos/XW/Morpheus/Hi-FW taken up a notch in engagement without losing any of the ease of taking in the entire view at once.  There's no comparison to the 12mm/17mm NT4s which are both very difficult to hold the entire view while wearing eyeglasses.

The 12mm Delos should be fantastic if my 10mm Delos is any indication.

A more appropriate comparison for the 12mm Delos would be against other long eye relief eyepieces in this range: 12.5mm Morpheus, 12.5mm Docter/Noblex, 12.5mm APM Hi-FW, 12mm Nagler T4 and 12mm ES-92 (did I miss any?).  I have the last three, and really like the APM for 1.25" use in smaller scopes and the ES for 2" use in larger scopes.  I can't afford the Docter/Noblex and consider the Morpheus too redundant with the APM and my 14mm Morpheus.  I should pass along the NT4 sometime because I never use it anymore.

On 07/04/2023 at 06:12, StevieDvd said:

What if the astronomer wears glasses 😀

Valid question.  I do, and I sometimes pick up reflections off of my eyeglasses on bright objects.  I'll shift my head angle slightly to move the reflection to be less annoying.

Also, off-axis light rays in wide angle views will suffer from chromatic aberrations, so I have to roll my entire head to look at the edge so the edge rays are entering my eyeglasses perpendicular to them.  This causes me to lose the opposite side of the view.

Contacts cure most of these ills, but I can't stand wearing them.

I've been using my Arcturus BV with the nosepiece from a Meade 140 2x Barlow screwed into the nose of the BV to reach focus in my Dob, and to boost focal length by 3x.  My Dob has has only 25mm of design in-focus, and I've tried this kit in various other scopes I own with only marginal focus shift from using an eyepiece alone, so I know it will reach focus in pretty much anything.

For eyepieces, I prefer smaller, lighter eyepieces such as the 20mm Svbony 68 degree red lines or adapted 15x B&L microscope eyepieces.  Big, heavy, wide eyepieces can be difficult to get your nose between and to achieve balance on smaller scopes.

The Barlow is vintage as are the microscope eyepieces, although I had a machinist make the adapters for me.  However, all up, I spent less than $400 on everything over the past decade, so I don't feel too bad using them so infrequently.

I've seen amazing details on Mars at opposition with this kit, so I know it's all working well together in the Dob.

Basic, entry level BVs can work fantastically well.  Just make sure to get a version that uses collets instead of thumbscrews to hold the eyepieces.  You may still need to fill undercuts with tape if the barrels aren't smooth to avoid tipping during tightening.

The original bins appear to be 10x50 and very similar to these ebay and amazon listings.

Apparently, the factory would print whatever you wanted on them for the right price.

I had my doubts about the 35 meaning 35mm objectives as well.  I figured it was either an 8x21 or 10x25.  So, basically, they got absolutely nothing right with their numbers on those bins, either.

I asked about the metal fittings because I've seen too many of the plastic leg clamps on the the rectangular legged aluminum tripods fail.  Once they crack in two, you can never extend that leg again until you replace or repair that fitting.

That's not to say that all metal is perfect.  I've also seen the top casting holding the three legs crack on some premium photographic tripods after being overloaded with the legs spread wide.

Ideally, CNC machined fittings from high quality billets of metal alloy would be ideal, but expensive.

7 hours ago, Don Pensack said:

The 24 was wider in true field, and brighter.

Of course, but what about the increased contrast due to the darker sky background?  That, and Uncle Al's whole "Majesty Factor". 😏

Here's a Tasco 60x35 on Mercari.  What's the 60 supposed to mean?

Is the 8° the apparent or true field of view?  At 60x, an 8° TFOV would be impossible.  An 8° AFOV would be miserable to use.

If I'm doing my trig correctly, a 76 meter field at 3000 meters amounts to a 1.45° TFOV, not 8° TFOV.  Assuming a 50° AFOV, that would amount to 34x, not 60x.

2 hours ago, Don Pensack said:

And because a 13mm yielded a 1mm exit pupil, which was high power in that scope.  24mm and 13mm would do fine for most observing.

Sounds like a 13mm Ethos might be the only eyepiece you'd need in a 127 Mak most nights if you could deal with the eye relief.  It would almost combine the 24mm and 13mm eyepiece functions into one.

Too bad for Pentax.  I've been fishing around for a Father's Day gift to myself, and the 23mm was one possibility.  I'll continue to give it a hard pass since Don and I seem to have similar eye socket depth.

C'est la vie.

It seems odd to make a knockoff of a Tasco binocular rather than a knockoff of a premium brand.  For reference, what sort of counterfeiter would make knockoffs of purses costing under $100?  The whole point of counterfeiting is to make huge profit margins, and that isn't going to happen making knockoffs of low-end products like Tasco.

My guess is that the same factory that makes Tasco had blems or extra product produced after they finished a run of official Tasco or similar binoculars and sold them as a lot to a jobber to recoup some of their losses.  The jobber may have had the printing added after receiving the lot.  That would explain why the collimation was off, assuming it wasn't due to mishandling by the original purchaser.