Louis D

Are the SLVs as easy to use with eyeglasses as the LVs once you got those stiff rubber eyecups folded back? I totally agree on the latter being a pain to use in the field, so I only bought the 9mm before moving on to the Pentax XLs. I've not noticed a distinct coffee tone in my 9mm, but I wouldn't doubt it because just about all eyepieces made with Lanthanum glass, such as the Radians, exhibit this to some degree. Last, does the 5mm SLV really have a 50 degree AFOV? I've read conflicting reports on the sub-9mm SLVs actually having the same 45 degree field as their predecessors. If it does have a 50 degree field and no coffee tone, I'll bet they were redesigned to avoid the use of Lanthanum glass for cost reasons and to open up the field 5 degrees.

I found a CN thread on this very subject. It is definitely hit or miss. I also had it happen to me on a 1992 vintage Sony Hi-8 video camera. The black rubber grip on top turned to goo in storage after having used it regularly without issues until switching entirely to digital in 2008. I dug it out again about 5 years ago only to discover it had turned to goo in storage. Neither the Rebel nor the camcorder had ever been exposed to solvents, Deet, temperature extremes, or humidity extremes, especially in storage which is when it happened.

Well, I know the LVWs were definitely discontinued over 5 years ago. I've also read that the SSWs are discontinued as well. The same appears to be true for the SLVs. Perhaps @FLO could chime in here with definitive knowledge on the subject.

First came the LVs, then the NLVs, then the SLVs. The first two were made in Japan, and the last made in China. The 7mm and 50mm focal lengths were dropped after the LVs and the 30mm redesigned and relabed as an NLVW. The sub-9mm SLVs claim to be 50 degree AFOV while those focal lengths were 45 degrees in the LV and NLV lines. The 8-24mm zoom remains unchanged as an LV. It appears that the 40mm NLV lived a short life between the LV and SLV lines. The original LVs had roll down rubber eye cups that revealed 100% of the possible eye relief. The twist up-down eye cups on the NLV and SLV lines always steal a few millimeters of eye relief away from eyeglass wearers. By all accounts I've read, the SLVs seem to be as well made as the original Japanese NLVs. I think the original LVs look totally posh compared to the later, plasticy NLVs and SLVs, though. LVs: NLVs: SLVs:

They might have come down slightly in inflation adjusted prices over the last 20 years since they were introduced, but they're still very expensive. They've never reached mainstream volumes, so I doubt their prices will ever come down. The original Canon IS binos' rubber armor turned to goo about 5 to 10 years ago, so there might be deals to be had on them. The same thing happened to my original 2003 Canon Rebel DLSR. I gave it away to a friend of my son's to learn on. I have no idea what he did to avoid the dreaded sticky, black hands syndrome from using it. I often had to resort to acetone to get it all off my hands.

If your budget is tight, get the Revelation/GSO coma corrector and add a 25mm extension between the optical section and the eyepiece holder. As long as your eyepieces focus with 5mm of the shoulder, it will correct over 95% of the coma in my experience, often far more. It needs about 11mm of in-focus, so most focusers can accommodate it.

Off-topic, so I apologize, but how do taxes on packages get collected in the UK? In the US, if you ship via a private shipper such as UPS or DHL, they do the collection and guess which tariff schedule to apply and charge a brokerage fee. It can soar to 25% plus a $50 brokerage fee. However, if you ship via the post office, the US post office generally makes no effort to collect anything on receipt after clearing customs. I don't know if it is a lack of interest or they are simply overwhelmed. Perhaps if they charged a $50 brokerage fee, they might be able to hire more help to collect taxes. I have bought lots of stuff from Europe, Australia, and China and never once payed any taxes on any of it.

Pretty much any dovetail bar can be attached to any tube or tube ring if you have the proper hex head cap screw (HHCS) to fit the threads on the tube mounting block or tube rings. They're generally 1/4-20 sized. Dovetail bars vary in style from extruded aluminum to CNC machined aluminum stock. Lengths and hole patterns vary widely. Some smooth holes and slots are for attaching the bar to the tube while others are threaded so accessories can be attached to the bar itself. The question is, does your dovetail clamp fit a Losmandy or D-style dovetail bar? It's much wider than the more common Vixen or V-style bar. There are some clamps that will accept both.

Are you saying the nut in the photo is solidly affixed to the upper tube assembly? If so, what keeps the bolt/shaft from rotating freely once adjusted to the proper distance to center it above the primary? For that matter, how do you rotate the secondary holder to square it back toward the primary once the the bolt is screwed in the proper distance?

Yep, that's the one. You'll need an open end wrench/spanner, either of a fixed size or adjustable (often called a Crescent® wrench in the US). While holding the secondary holder in the proper position to have it aimed directly at the primary, tighten that nut down against the upper tube ring. The binding action should keep the secondary from twisting. If it keeps working loose, try fitting a lock washer between it and the upper tube ring (after completely unscrewing the holder bolt) to prevent it from loosening. Just note the number of exposed threads before removing it so you can reinsert it to the same centered position.

She probably thinks you're compensating for something else, but she'll never say it.

Nor the US if I recall correctly.

Not really practical for eyepieces with a Smyth lens in the lower barrel, either.

Always wear white cotton gloves when observing? 🤔

Just make it a roll-off roof instead.

Visual only. I just can't stand false color having started with reflectors. Even the AT72ED's false color at higher powers was starting to grate on my nerves. So far, I haven't noticed any false color in focus with the 90mm.

Can you buy from Telescope House? Their Revelation version is only £65.10.

Yep, mostly starfields big and small because of the level of light pollution in my backyard. It wasn't bad 25 years ago when the nearest small town was 4 miles away. Now I'm surrounded by a tollway, tens of thousands of new homes, several giant shopping centers, multiple schools and their lighted fields, car dealerships, etc. I'm seriously considering moving to darker skies when I retire.

I just realized if he covered everything in a mixture of chrome and brass, it would look seriously steampunk like this Moonraker scope:

Well, a lot of folks had issues merging binoviewer images when the eyepieces were held by three screws instead of a single collet (not sure if undercuts were involved since I never owned one of these binoviewers). You rarely see binoviewers these days being sold with three screws per eyepiece holder. However, the collet-style holders still have issues with the undercuts causing eyepieces to tip. I prefer eyepieces with no undercut for this reason when using binoviewers. I'll agree that I've not noticed any difference in concentricity of a single light path when using 1, 2, or even 3 screws to tighten a diagonal or eyepiece into place.

Have you tried pinstriping tape from the automotive supply store? This CN poster has had good luck with it.

My wife used to have an entire bedroom dedicated to her crafting supplies and tools. Our third child put an end to that. Now that they're all grown, I'm surprised she hasn't taken it over again.

The only issue I've noted with the GSO CC is at small exit pupils where the image is not as sharp as without it. I'm guessing it has some residual spherical aberration at high powers. I've never noticed a decrease in transmission, but I've also never gone looking for it. I've noted a similar issue with the TSFLAT2 field flattener in my 90mm APO. The image has some chromatic aberration at small exit pupils with it in place, so I remove it under those conditions. For the $75 I picked it up for used, I have been very impressed with the GSO CC. I imagine the Paracorr T2 would certainly be better, but I can't justify the nearly $500 price tag for a slight improvement. Perhaps if I was an imager I could justify it.

I've already got a 20+ year old ST-80 that is pretty poor all around, an AT72ED, and a TS-Optics Photoline 90mm f/6.6 FPL53 Triplet APO; so no, I'm good on small refractors. However, if I had none of these scopes, they would probably be far preferable to the ST-80 as a starter scope. Some of these refractors appear to be almost identical to some of the ED scopes out there minus the expensive glass.

It's where the insertion barrel (1.25" or 2") meets the wider part of the eyepiece that stops further insertion into the focuser. In TeleVue's eyepiece specifications page, the following diagram shows this clearly as where the white part meets the black part. Dimension F is the focus position in their table. Positive means below (the little x in the diagram) and negative means above the shoulder. Often, the focus position does not correspond to the physical field stop if there is a Smyth lens in the insertion barrel, so I think their diagram should have labelled F as focus position rather than field stop (perhaps effective field stop would also be acceptable), because that is what it indicates in my experience with their eyepieces.