Louis D

5 hours ago, Piero said:

Oh dear.. It's easier to think in terms of "how many cases do you have?"

8

5 hours ago, Peter Drew said:

Never counted them but must be in three figures.    🙂

Sounds like I've got some work to do.

4 hours ago, JeremyS said:

5th amendment 🤐

Sorry.  As a Brit, you're not covered by it.  Time to fess up.

75 not including bino duplicates.

Here's a somewhat out of date group shot including Barlows and BV.  The Svbony 3-8mm zoom and Aquila Planetary II SW 2.5mm are missing, possibly others as well.

Come on down to Texas, then.  We haven't had clouds in weeks/months.  No rain, either.  100+ for weeks, 105+ for 10 days and counting.  I tried to go out and observe for a little while last week, but I was dripping sweat on everything within minutes even with a box fan blowing on me because it was still 97 degrees and 70+ degree dewpoint at 10pm.

* All temps in Fahrenheit.

With smaller SCTs and Maks, you will get vignetting in the outer field of 2" eyepieces having field stops larger than the rear baffle/rear port diameter.  The human eye is rather insensitive to this, especially if your attention is focused on-axis.  2" eyepieces can be useful to provide context for objects, or to get them centered for higher powers.

If you plan to look at nebula with a line filter (OIII filter, for instance), then a 1.25" 40mm Plossl might help by increasing your exit pupil and making the nebula appear brighter despite being smaller.  It does this by concentrating the available light into a smaller area.  The difference in exit pupil with a 32mm vs. 24mm pupil wouldn't be great enough to warrant purchasing a 32mm Plossl for this reason only.

You can't go wider than 50 degrees at 32mm.  It's a physical limitation of the 1.25" barrel's inside diameter where the field stop is located.

Your SCT is quite slow at f/10 and is therefore rather undemanding of eyepiece quality.  Your BHZ will certainly serve you well in it.  You also don't want to go much shorter than 8mm for an eyepiece because the exit pupil becomes very tiny with an f/10 scope.

The various 24mm Ultra Flat Field eyepieces would also be a good option for you for a widest field of view at the low power end.  Even the 25mm Starguider Dual ED performs decently well at f/10.

3 hours ago, Mark2022 said:

Louis, I don't "buy it" that, to add half an inch to the inside diameter of the existing designs need to add a factor of 10 to their cost.  You can pick up these eyepiece projection adaptors for a tenner or a bit more.  There is absolutely no need for a significant increase in cost because of making the barrel diameter 10 mm or so greater. I keep finding, with this hobby, that I wish I had some turning machines and a little workshop.  The rip offs are ridiculous.

Going even further in the wrong direction price wise:

VariMax™ Variable Eyepiece Projection Adapter w/ 1.25" Barrel

I had never even heard of these before.  Looks like some pretty decent quality as you would expect for the price.

Paul Van Slyke of Van Slyke Instruments near Colorado Springs, CO, used to make high quality hand made astronomy gear in his home machine shop until a forest fire totaled it about a decade ago.  His stuff wasn't exactly cheap, though.

7 hours ago, johnturley said:

I don't find undercuts a problem with the Baader Clicklock system.

John

Because they use a wide collar, not a narrow compression ring, that avoids snagging in undercuts.  The Antares 2" to 1.25" Twist-Lock adapters are similar:

13 hours ago, Mark2022 said:

Thanks Louis. That's just the product I would need but, I'm afraid, way out of my budget. I have no idea why manufacturers can't just make one with a wider/longer barrel of the type we are accustomed to.

Because they would cost as much as the MaxView adapter, and no one would buy them.  That is what happened to the MaxView, and now they are no longer made.  Instead, they sell small, cheap adapters that don't work with modern eyepieces to hit a certain price point.

14 hours ago, Alan White said:

But David Nagler insisted I was wrong suggesting such a thing, flat refused to believe me that the undercuts were an issue….

It's your focuser that is the problem for having a compression ring to snag in an undercut according to him.

39 minutes ago, Highburymark said:

The Pentax XO is a plossl-type design, and they succeeded in making an EP with clear, on axis improvements over other eyepieces.

Plossl in that the image forming section is two doublets.  Beyond that, it is a highly optimized negative/positive design of 5 or 6 elements:

On 13/07/2023 at 00:07, Franklin2324 said:

I’m doing my best to learn about agronomy

I would have you reach out to my alma mater, Iowa State University.  They have an entire Agronomy Department. 😉

So, excellent on axis, terrible off-axis?  They're probably intended for driven mounts and planetary observations done on-axis.  Probably a poor choice for a large, f/4, undriven Dobsonian.

10 hours ago, Jim Smith said:

I wonder how much sky the Seestar 50 needs to see to carry out its automatic alignment. I have quite a few big trees that block a lot of the view from my back garden.

I was wondering the same thing.  I have about a 20 degree slice of the southern sky from 20 degrees above the horizon up to zenith visible from my back patio.

My 6" f/5 GSO Newtonian also shows plenty of detail on the planets.  My 127mm Mak also does, but with longer cool down time.  Even my 90mm APO shows Saturn's rings and Jupiter's bands quite clearly.  Something's amiss with your 130mm Newt.  Perhaps it's mirror is not properly figured?

13 minutes ago, Mark2022 said:

Anyone have an idea how I can use a 5mm LER  planetary eyepiece with eyepiece projection? That's the answer I'm looking for, if such exists.

Look for a Scopetronix Maxview DSLR.  It can easily accommodate your 5mm eyepiece.  That ebay offer might be the only new old stock one in the world.

23 hours ago, badhex said:

Dang, I hope you got a really good price on them.

I've got a single coated 26mm Sirius Plossl from the 1990s that has some sort of coating hazing going on, but no scratches.  It doesn't seem to affect the view through it all that much, but it's still annoying the seller didn't disclose it.

Thos eyepiece projection adapters haven't changed in 40 years.  They were intended to be used with the Kellners and Orthos of the day.

That being said, why would you want to push your SCT with the equivalent of using a 2.5mm eyepiece?  It already has a ~2000mm focal length natively.  Going to projection with a 2.5mm eyepiece is going to massively increase the image scale.  The f-ratio is going to drop from f/10 to f/400.  That's insanely slow with a 0.25mm exit pupil.

Why not just try using the DSLR natively on the scope with a 1.25" or 2" (depending on your visual back size) to T-thread adapter?  Guiding a 2000mm focal length scope is difficult enough.  From there, you could progress to high powers with the Barlow alone if you think you still need more magnification.

Maybe I'm misunderstanding your use case.  What do you plan to image/photograph?

Actually, they're just overexposed.  They don't appear to be particularly "bad" other than that.  Try adjusting the exposure compensation feature on your phone's camera toward the minus sign or dark sun or simply to the left on the slider, so less light is collected for each exposure.  To access it, bring up the camera tools (perhaps a gear or similar icon) and look for a sunburst-like icon, IIRC.  Another option is to tap on the bright part of the moon on the screen to force focus and exposure to be centered on that region of the image.  However, this approach is difficult to do without a holder, but you can try it.

So, a more compact version of all those telephoto lens attachments for smartphones already out there?

Pick up a Svbony 3-8mm zoom and try the different magnifications yourself to see if you are missing any "in between" fixed focal lengths.

On 19/04/2023 at 15:26, Ags said:

I have been very anti-smartscope, but at this price point and this cuteness level, I WANT one of these!

https://www.firstlightoptics.com/beginner-telescopes/zwo-seestar-s50-all-in-one-smart-apo-telescope-tripod.html

It looks absolutely amazing, really good value for money.

Can you be specific on the range of topics you would consider appropriate for this thread's discussions to help clear the air, so to speak?  Your opening post seems very wide open and nonspecific; thus, the wide ranging discussions that seem to have repeatedly offended at least one member as being off topic for this thread.

2 hours ago, LDW1 said:

The big question has always been why, when talking to the average observer that just wants to enjoy.

I guess the question then is, is this astro-cam more for observing or imaging?  If for observing, then noise and image quality don't really matter much at all just so long as the image provided satisfies the observer.  After all, look at how noisy night vision devices are.  The image positively sparkles.  If for imaging, then noise levels are a legitimate point of discussion along with many other image attributes.