Scott42

Interesting, I didn't know you could use the microwave.  I've been baking them at 250 degrees F for 15 minutes, seems to get the job done.

I didn't think of weighing them to confirm the drying out - great idea.  Will try that next time. 

I suppose if we wanted to read CN we'd be logging in there instead of this site.  

I've got the TOE 4mm and it's very nice but it's a 6-element eyepiece.  6 element eyepieces cannot perform like 3 and 4 element eyepieces on contrast, scatter, and clarity.  The pure whiteness of a 3 element eyepiece is exactly what I would expect versus a 6 element eyepiece, along with a subtle improvement in contrast.  You can't pile a bunch more glass into the eyepiece and expect the same clarity.

I keep Tak LE 7.5mm, 5mm, and the TOE 4mm in my case and use them most of the time for high power because of the wider field and increased eye relief over orthos.  But if seeing is good and I"m not sharing the views with clumsy people at outreach events (!) I will break out my AP SPL 4mm, 5mm, and 6mm.   The difference between them and eyepieces with a barlow inside is like the difference between getting fresh bread at a bakery versus bread in a plastic bag at the supermarket.  It's like removing a veil from covering the planet's disk in terms of clarity.

However, the SPL's have better eye relief than abbe orthos.  The tiny eye relief of 4mm and 5mm orthos is nearly intolerable for me and difficult to use on undriven mounts.  FWIW, I think using a quality barlow like the AP Barlow with longer orthos is also superior to eyepieces with a barlow inside.   I suspect it's because of the larger diameter lens in the barlows - the negative lens in the TOE is absolutely tiny.

IMO, Takahashi and Fujiyama are the best orthos out there today.  Between the two of them you should be able to cover all the focal lengths.  Beware the 4mm and 5mm orthos have extremely tight eye relief

Am I the only one wondering about this alt-az mount?  It looks good, I'd love to see Tak offer it by itself or with the tripod. 

It's got slow motion controls and a nice handle, if it works with this scope its should work with shorter-focus 100mm scopes.

How cold are we talking here?  Frigid?  The grease in most mounts should work fine in cold temperatures.  That said, I don't observe much below 20 degrees F. 

Orion still sells this mount - why not ask them?  Hopefully they can give you a minimum operating temperature.

are we talking 1.25" diagonal or 2"?   If you're trying to keep it small & light the Takahashi 1.25" prism would be nice, it has a very short light path, it worked fine on my f/7.5 refractor.  Probably better to stick with a mirror diagonal in the 2" size IMO.

Can you tell us more about this scope - how do you like it compared to the other Borg's you've had?   Is that an FT focuser - did you choose it over the Borg R&P focuser?

I just received a TEC140FL from Anacortes in Washington State, USA, they ship internationally and have a TEC140FL ready to ship NOW if you want one

https://astromart.com/classifieds/astromart-classifieds/telescope-refractor/show/tec-140-new-in-box-shipping-in-a-few-weeks-first-come-first-served-one-available

IMO the optics are first-class in the Tak prism, I've had mine for many years with no plans to give it up.  I keep it in my eyepiece case all the time as a backup, in case something disastrous happens to my 2" diagonal during remote observing trips.   Stu's right about the collet catching on eyepiece undercuts, you must use a little more attention when changing eyepieces.

I"ve got the Tak prism diagonal and it's worked well for me at f/7.5.  I think it would be fine at shorter f-ratios.  Keep in mind the length of the glass path of a prism diagonal is what determines how much color error it adds.  The Tak 1.25 diagonal probably has a very short path - as someone pointed out.   The T2-size prisms from Baader will have longer path and actually introduce more color error.  

But in general the color error is only an issue in big 2" prism diagonals that have a 4 inches of light travel through the prism glass.     I believe the Baader t-2 is only a 2-inch light path?   something like that.  So the Tak is probably even shorter.

It should be said the weak point of the Tak diagonal is the plastic twist-collet used to hold eyepieces.  It's a little weaker than metal compression ring clamps.  It's not great with big & heavy eyepieces.  Some people don't like it.   It works well enough for me.  It's perfect for small grab-n-go refractors where you're trying to keep the size and weight to a minumum.

Maybe it's premature to give up on these Erfles, if you're using a 2x barlow for binoviewing the eyepiece will get an f/15 light cone (assuming an f/7-8 telescope).  It might work OK there, I only used it at f//7-f/8.   It's not possible to make a slim, lightweight wide-field eypiece that works well at f/7.  I'm thinking the Tak Erfle must perform better at f/15 or they wouldn't have started making it again.

With that big undercut in the barrel they better hope Apollo 11 doesn't snag on the launch tower on the way up!

I had this eyepiece for a while.  It has the high-quality Takahashi glass and coatings I like, but the Erfle design had very bad edge correction in the f/7-f/8 refractors I use.  It seemed like the eyepiece was designed to be used at f/10 and above.  I've had other "Erfle"-marked eyepieces that did better at f/8.   It might work well in a bino-viewer if the f-ratio is mulitplied up into the f/10-f/15 range.

I would recommend something like 30mm Tak LE's instead.  The FOV is a little smaller but they perform well at all f-ratios.

On 01/08/2019 at 20:46, Louis D said:

Wrong 30mm APM.  That's the much older Widescan III clone.  It has severe field curvature leading to blurry edges.

This is the 30mm APM UFF I'm referring to.  It has 9 elements in 5 groups:

Thanks for setting me straight!  I've used the WIdescans-types before.  So the UFF has some more lenses to flatten things out.   I see that there is no "safety groove" on the APM which is fantastic.   Weight is very reasonable at 19 ounces.

It looks good - not too heavy - and the price is right, I'd like to try one....the body looks similar to the TMB Paragon series.  Only 5 elements and 80 degrees, sounds interesting.   I did like the XW40mm better than the Paragon 40mm but the XW40 is far heavier.

https://www.apm-telescopes.de/en/eyepieces/more-74-ultra-wide-angle/apm-lunt-eyepieces/apm-eyepiece-uw-30-mm-80.html

No one has mentioned Pentax XW's so I will....30mm and 40mm.  Currently only available on the used market.  I did a grand face-off contest between the TV offerings and these two - 41mm and 35mm Panoptics, 31mm Nagler.  The XW's are a bit lighter which was the first reason to try them.  They weigh about the same as the 35mm Panoptic, which is lighter than the 41mm Pan and 31mm Nagler.

After many comparisons I became a big fan of the XW's.  Under careful examination I got the impression that all 3 TV eyepieces imparted a yellowish tone to the stars, where the Pentax appeared pure white.  Also the XW's do not employ rectilinear distortion, so the stars appear normal when panning around, instead of visibly bending as the FOV moves across the sky.

Because there is no rectilinear distortion, the 40mm doesn't work so great at lower f-ratios typical of big Newts - you see the field curvature at the edges where the Tele Vue keep the stars as points to the edge.   However the 30mm XW has better edge correction and it's worked well for me at f/5.6.  Between the two of them you have a great high-contrast eyepiece that works well on long & short f-ratios.  I've avoided the ES eyepieces because of heavier weight.

There is no need to contact Astro-Physics - these Travelers are all the same except for the outside finish - this is the "anodized" version or smooth.  This scope looks to be in outstanding condition!   If I was going to post it on Astromart I would include the accessories and ask $5,500.  I would let it sit for 2 weeks before considering any price reduction.   Many people prefer the anodized version but it's difficult to find one in this condition.  Also it would be very unusual for this scope to be suffering from any kind of misalignment or other problem requiring service.

If you're going to ship it, the scope should be in the black case with 1-2 inches of foam around the case in a sturdy box.

The metal rod and the heavy weight in your picture are not part of the telescope - they're parts from the separately-sold mount (telescope base).  This telescope was typically sold with the Astro-Physics 400 mount.  It's a black metal machine about 1 foot in height.  The metal rod is the counterweight shaft from the 400 mount - it screws into the mount.  If you have the complete mount it will be worth another $2500-$3500 depending on which version of the 400 mount you have.   The mount was also sold with a large wooden tripod.