Louis D

This is in large part true because many 1.25" eyepieces these days use a negative/positive design, much like having a Barlow ahead of the image forming eyepiece.  This allows for better correction and longer eye relief.  That positive-only image forming section has a fairly long native focal length.

To accomplish the same thing with two inch eyepieces would require really large positive sections having a very long native focal length.  My 35mm Baader Scopos Extreme is an example of this approach.  Below is the optical design schematic (eye lens at left, negative field lens at right) and an image of mine side by side with other similar focal length eyepieces.  It's also 38 ounces, so right in between my two ES-92s in weight.  And yes, it has very good correction as shown in the last image.

1 minute ago, Tiny Clanger said:

Not if your newtonian does not have a 2" tube.

My newtonian does not have a 2" tube.

Then you can try using a short 1.25" extension tube inserted into the focuser with one 1.25" polarizer screwed into the bottom of it and the 1.25" eyepiece with the other filter inserted into it.  Of course, this assumes you have enough in-focus to accommodate the extension tube's additional optical path length.

On 22/02/2021 at 07:23, Tiny Clanger said:

Less good in a Newtonian where both go on the EP, so you need to remove the EP to rotate the filter.

Not if you get a 2" and a 1.25" linear polarizing filter.  Screw the 2" into the front of the 2" to 1.25" adapter, insert the adapter into the focuser, screw the 1.25" into the bottom of the 1.25" eyepiece, insert the 1.25" eyepiece into the 2" to 1.25" adapter, and there you go!  Just rotate the eyepiece to vary the dimming.  It works great for me for solar observing in particular (with a full aperture solar filter, of course).

1 minute ago, Don Pensack said:

Wouldn't it be nice if eye reliefs were stated in terms of the optical configuration (from the glass) and the ergonomic configuration (from a horizontal line across the top of the eyepiece).

I would argue the 2nd eye relief should be measured from the folded down rubber eyecup, and not the aluminum below it.

I'd also like standardization on how apparent field of view is measured and have vendors quote accurately measured numbers using this criterion for each and every eyepiece, not just for a particular eyepiece line as a whole.

That, and quote accurately measured effective field stops so users can calculate true field of view accurately.

Televue's specs are pretty close on these, so they could be held up as the gold standard for others to follow.

4 minutes ago, Don Pensack said:

No formula, but 10-15mm eye relief is comfortable without glasses, and 18-24mm with glasses.

Eye reliefs in excess of 24mm or shorter than 10mm are a problem.

And take manufacturers claims of eye relief with a large dose of skepticism.  Most quote designed eye relief to the center of the eye lens, which can be much less than the usable eye relief if the eye lens is deeply recessed or deeply concave.

16 hours ago, John said:

But what you REALLY need is 1000 cents ......

Do y'all secretly use US coinage for trade in thoughts over there?

Were the Hanimex made in Japan?  My Japanese made binos from the 50s to the 90s are all made to a higher level of mechanical perfection than my more recently made Chinese binoculars at similar inflation adjusted price points.  Focus is smoother, eyecups don't come unglued during adjustment, no hokey internal stops to reduce clear aperture to improve optical performance, wider apparent fields of view, etc.

Do you have a 2" diagonal for it?  If so, a 30mm APM UFF or equivalent (Altair Ultraflat, Meade 5000 UHD, Celestron Ultima Edge) would be a very good choice for wide field views.  It is basically flawless in my f/6 Astro Tech 72ED.  You may notice field curvature, though, due to the very small radius of curvature of your new scope (420/3=140mm).  I know I sure did with my 72ED.  I ended up springing for a TSFLAT2 mounted 15mm in front of the body of my 2" GSO dielectric diagonal to flatten the field.  I do remove it for high power work because it contributes some spherical aberration at high powers.

2 hours ago, SiriusB said:

minus points? On the odd fl, anodizing was not perfect, one ep had slightly jagged field stop~ this all seems fairly common with budget Chinese ep's, minor quibbles for the low price.

Check to see if they're labeled/marked Taiwan anywhere, including the boxes.  I suspect they are made by GSO of Taiwan.

1 hour ago, Deadlake said:

I was just imagining the lengths people go too.... 

Found it.  The 10% luxury tax was enacted in November 1991 and the yacht part was repealed in August 1993.  The car part wasn't repealed until 2002.

Imagine buying a $3,000,000 boat, only to have to pay another $300,000 just because of where you bought it.  It was probably cheaper in the 90s to buy a yacht anywhere else than the US, and this just sealed the deal to buy elsewhere.  As long as you didn't flag it in the US, there wasn't any way to compel an owner to pay the tax avoided.  The wealthy didn't get that way by beings stupid with their money.  Ever notice real estate developers (like a certain orange one) put up very little of their own money?  Instead, they rely on "partners", "investors", and bank loans secured by the property involved to finance their deals.  This greatly limits their downside exposure in case of bankruptcy.

First, I would go slowly by hand with fine emory cloth if the amount to be removed is localized and of a small amount.  Dremel tools can be very aggressive and will remove a lot of material before you know what happened.  I would use one only as a last resort.

2 hours ago, Deadlake said:

Well its standard approach here as well, issue is with lenses. LZOS lens cell for a 130 mm/F6 is retail around £3800. Don't know how thats going to get thru, one part of the triplet at a time? 🤣

I never claimed it would work in all situations.

The law of unintended consequences comes to mind about now.  Back in the 80s or 90s, Congress enacted a luxury tax on all yachts sold by American companies to "stick it" to the wealthy.  This had the unintended consequence of putting thousands of American yacht makers out of business (including my cousin in New Jersey) because the wealthy simply bought foreign made yachts and registered them overseas before bringing them back to US marinas.  Needless to say, that stupid law was repealed after about 15 years, but the damage had already been done.  The US yacht building industry has never really recovered.

53 minutes ago, John said:

From when I was a moderator here I recall we did discuss this quite often but the conclusion was that we worried about "silos" developing as is the case to some extent on CN.

Unfortunately, in trying to prevent silo'ing, it may just push discussions into the wrong forums for lack of a better place.  In particular, the beginner forums.  Recently, I've noticed more than a few advanced threads in them that didn't really belong there.

21 minutes ago, Deadlake said:

I don't see the 25% tarrif on china changing, its the new normal. Guess eyepiecesetc.eu is required, no orders above $800. 😀

I'm picturing $800+ APOs sent from Europe to the US as tube, lens cell, and focuser all separately on different days to legitimately keep the cost below $800 per individual per day (the letter of the law here).  Some minor assembly required.

1 hour ago, Carl Au said:

I love this forum, but there is a place for talking about the high end stuff, getting started general help and advise isn't it. I was just picturing the face of a beginner on seeing the price of a 4 inch japanese refractor for the first time with nothing else to base an opinion on. Perhaps there should be a seperate forum for such things like they have on CN? Just a thought? 

On a completely unrelated matter I had an excellent session last night, big moon or no...

I've often wondered why there are four beginners forums, but only one Scopes/Whole setups forum.  Why aren't scopes split out by type as on CN?  A refractors forum would have been the natural place for this thread, but it doesn't exist on SGL for unknown reasons.

40 minutes ago, Deadlake said:

How long with the $800 allowance last?

Indefinitely on that point.  It was raised from $200 in March 2016 under Obama, and Trump left it alone during his four years, and since Biden is basically Obama v2.0, I don't foresee it being changed any time soon.

We're starting to see the 25% import tariff in the US on goods labelled as made in China.  It's not clear how diligent customs is being on items like APM UFFs marked as Germany instead of China.  US customs has been applying the 25% tariff very inconsistently even when items are clearly labelled as made in China.  I may be buying more Chinese made goods from the UK/EU since personal imports under $800 are duty free and not checked for the 25% made in China tariff and individual retailers are not collecting the appropriate US state sales taxes because they have no nexus of business in the US.  On net, these tax/duty/tariff savings easily pay for the additional shipping charges.

11 minutes ago, Aquavit said:

Am I right in assuming then that this is a not uncommon phenomena and not a consequence of mis-matched equipment and/or my eyes?

Correct.  It's not like viewing a monitor screen where alignment is irrelevant.  Your eye's entrance pupil has to be exactly aligned with the eyepiece's exit pupil, not only in the left/right and up/down sense, but also the in/out sense as well.  It's a learned skill like riding a bike.  After some time, it just comes naturally and you don't think about it any longer.  That is, until you meet up with an eyepiece with loads of spherical aberration of the exit pupil (SAEP) or kidney beaning.  In this case, it's a fault with the design of the eyepiece that no matter how careful you are, you cannot take in the entire field of view at once.  The best remedy for this is to not buy such an eyepiece in the first place.  That's where the SGL community comes in handy.  We can steer you clear of eyepieces with known design issues such as SAEP.  As far I know, your current eyepieces are not known to have such design issues.

17 minutes ago, Aquavit said:

I normally observe standing up but will try sitting down tonight.

I'm 9 years your junior, and I can't hold myself steady for more than a few minutes before fatigue sets in while standing and observing.  You need to be relaxed and comfortable to get the most out of astronomical observing.

6 minutes ago, Aquavit said:

I don't wear specs to view but I was conscious of choosing an EP with reasonable eye relief as I assumed that that was only a good thing. Could the amount of eye relief (ie too much) explain the "barreling" effect I'm experiencing?

Or is it me that needs to get used to viewing through eyepieces???

If by barreling you mean seeing blacks or shadows as you move your head around; then yes, you're inside the exit pupil and are too close to the eye lens of the eyepiece.  There are eyecup extenders or tall eyecups that might help with the 32mm Plossl by giving you a frame of reference for where to keep your eye relative to the eyepiece.

Are sitting while observing?  It's just about impossible to remain still enough while standing to successfully hover above an eyepiece.  There are adjustable observing chairs of all sorts that can help with this.

7 hours ago, technocat said:

wow thats very impressive! if thats the case then im sure the 8x42 vortex diamondbacks i ordered will will work just fine  I wanted a very compact and versatile tool, no reclainers, no tripods/monopods, no lying on the ground. Just whip them out wherever you are, point up and start looking. Very excited to try them out

Then the 8x42 bins will work great for that.  I have a Meade Safari Pro 8x42 from the late 90s that still puts up great views and is eyeglasses friendly with a 65 degree apparent field of view.  The Diamondbacks should be lighter being roof prisms instead of porro prisms, so probably even easier to use handheld.

1 hour ago, Thalestris24 said:

PS it's almost essential to have the image train parfocal with the visual. It's also nice, but not quite so essential, to have the imaging fov the same as the visual

Once you have the binocular section focused, hopefully you can move the trinocular eyepiece up and down to reach parfocality and then lock it down as well.  You should also be able to focus the trinocular eyepiece using live view from the camera to a monitor screen.

40 minutes ago, Thalestris24 said:

Well, I'd need 2 of them...

I was thinking of a single one for the trinocular tube to take low distortion, afocal images.  Distortion isn't all that important visually at the binocular viewer.

Moving up in aperture at a similar f-ratio with the same objective design will naturally result in poorer color correction.  Replacing FPL-53 with FPL-51 at a given aperture will reduce color correction further.  An FPL-51 triplet has similar color correction to an FPL-53 doublet, but with longer acclimation times.  This is all theoretical, though.  Visually, you'd be hard pressed to notice the difference except on the brightest objects at the highest powers.  Photographically, you get more blue/violet halos around bright stars from what I've read.

On 20/02/2021 at 08:39, F15Rules said:

Be aware also that nothing is for nothing, so if you're tempted to jump straight in with "cheap" 15x70s or 20x80s, they often have poor quality control and the least knock can ruin the collimation (alignment) of the objectives.

I've had my $69 Galileo 15x70s for over a decade and have traveled extensively with them and have yet to have them go out of collimation.  Sure, they only have 65mm of clear aperture, but they've given me and my family many great views both terrestrially as well as astronomically.

You can always rig up a reclining lawn chair for binocular observing like this guy on CN did to get better comfort and stability.

2 hours ago, MiladyB said:

Thanks for all the help, everyone!

My binos are on the way I have a nice zero gravity recliner for the garden so I'm looking forward to a (hopefully) chilled out session with them soon. 😊

Now you just need to trick out your recliner like this guy did on CN.