Fast Newt's, binos and fast refractors are all very different optical beasts. They all present very different focal plane shape and other challenges for an eyepiece to deal with. And for an eyepiece to deal well with each scope design, it is staggering. The price tag is not a surprise, nor is it that this eyepiece comes in just one single focal length - to create a line of focal lengths that perform the same like this piece in so many different scope designs is close to impossible. We see this performance variation in all brands and models. BUT, we do see that there are some single focal length pieces that do perform exceptionally well in different scope designs, like this Docter. None of these eyepieces cost chicken feed either!
If someone does manage to get their hands on one of these Docter pieces, I hope they will be able to give a review using the eyepiece in different scope designs, Newt, SCT, refractor, etc, not just the one. Neat too, not just with a coma corrector or other devise. With so many combinations of scope and eyepiece, it will take some time to complete! Oh what a dreadful, loathsome task...
I can tell you about my binoviewing experience with two Docter UWA 12.5, but nothing about the Naglers (I don't have any Naglers). I recently purchased a pair Docter UWA 12.5 for my Baader Mark V binoviewer. Some positive remarks of our "Dr. Homma" (Tammy) encouraged me to purchase them.
First and most important, if you are interested in the Docters, a strong and rigid focuser is absolutely mandatory, able to support a 6 lbs. load without stress and able to hold that load in focus even with tube in full vertical position.
First the good things:
The first impression was very positive, these are quite heavy and decent looking eyepieces. And yes, the Docter UWA 12.5 pair work fine in bino action. I don't have any problems with merging both views and found the eye placement to the eyepieces very comfortable and relaxed. Due to the quite compact (55mm) body diameter of the UWA 12.5, there remains enough space for nearly everyones IPD and nose (my personal IPD is 62/63mm, and yes, I have a quite large nose). I fully agree with Tammy, these are outstandingly comfortable UW-eyepieces (84°) for binoviewing.
My first light test scenario for both UWA 12.5 was as following: Takahashi TOA-150B f/7.33 (with reinforced 4" standard focuser) -> Baader 2" ClickLock clamp for Tak -> Baader 2" nosepiece #16 -> Baader Fluorite Flatfield Converter (FFC) set at approx. 4.5x focal extension -> Baader T-2 1 1/4" Maxbright diagonal mirror -> Baader Mark V bino (without any glasspath corrector inserted) -> 2x Docter UWA 12.5. Resulting magnification of this combo is about 396x at f/33.
Test object was the Moon and first light with the UWA's 12.5 was simply breathtaking. They deliver a widefield image sharp over the entire field, with perfect detail definition and brutally hard contrast. Absolutely no false colors visible at moon limb, no matter if looking at the center or the outermost edge of view. The background perfectly deep black like velvet. I felt really impressed (or should I say shocked) by the UWA 12.5. There remains no doubt that the UWA 12.5 is an absolutely outstanding and very comfortable widefield eyepiece, perfectly harmonizing with a binoviewer, even when pushed to high powers. I wouldn't hesitate to recommend them to you, if your focuser supports such a load as previously stated.
I can see by this report that I may be up against a focuser issue ...my TV Genesis Focuser may not be enough to handle the ' weight ' of 2 x Docter and a Bino combination....I will have to see.
When it arrives, I will put my Bino on my Scope and place the Docter eyepiece into it ....make a judgement that way.
There's one on Astromart now for $600USD if anyone is interested.
I considered one, but the fact there is only one focal length is a deal breaker. Plus I prefer 100 degrees in the mid and long focal lengths to help frame the big targets at lower power.
The Docter is very popular among the glasses wearing crowd who sometimes struggle with the Ethos a bit.
Photos of size comparison with other TV Eyepieces.
I doubt I'll be getting a 2nd Docter Eyepiece, as the Focuser on my TV Genesis is not suitable to hold the ' extra ' weight ....
Will certainly enjoy using just one anyway...
Credit to Tammy on CN for the Photos.
Col....
Last edited by FlashDrive; 25-04-2015 at 08:30 AM.
Photos of size comparison with other TV Eyepieces.
I doubt I'll be getting a 2nd Docter Eyepiece, as the Focuser on my TV Genesis is not suitable to hold the ' extra ' weight ....
Will certainly enjoy using just one anyway...
Credit to Tammy on CN for the Photos.
Col....
see post #26 above Size seems to be similar to the Vixen LVWs so may not suit narrow IPDs
see post #26 above Size seems to be similar to the Vixen LVWs so may not suit narrow IPDs
LVW's work OK for me in Bino's ....may consider getting a pair of 13's or 17's soon .... the 24 pan's are a delight to use....very comfortable viewing, looking at Eta, the Nebula just fills the whole view... ( intermediate low power with a 68* degree fov ) ....brilliant match ...
Col.....
Last edited by FlashDrive; 25-04-2015 at 10:26 AM.
Reason: spelling correction
Must be sower getting to Deception Bay than here - my OLD MEF focuser (different style fine wheel, different reduction)cleared Customs 26th, arrived this morning
Now just making a torque plate for it (again different to the current MEF's).
Now, I am quite happy to test your Docter Col... just let me know, I promise I'll return it quickly (considering local time dilation, I estimate that to be 27 years... give or take a few)
Must be sower getting to Deception Bay than here - my OLD MEF focuser (different style fine wheel, different reduction)cleared Customs 26th, arrived this morning
Now just making a torque plate for it (again different to the current MEF's).
Now, I am quite happy to test your Docter Col... just let me know, I promise I'll return it quickly (considering local time dilation, I estimate that to be 27 years... give or take a few)
I rang them and gave them my address as an amended delivery address!!!
Waiting patiently for the Docter!
Got my Feathertouch MPA from Wayne at Starlight this morning, smooth as silk again, they replaced all the internals and recalibrated the thing. Might put it on the TOA with the new pinion.
I rang them and gave them my address as an amended delivery address!!!
Waiting patiently for the Docter!
Got my Feathertouch MPA from Wayne at Starlight this morning, smooth as silk again, they replaced all the internals and recalibrated the thing. Might put it on the TOA with the new pinion.
Actually Matt I am sure between the two of us we can do an excellent job of conducting a full review on Col's new eyepiece for him. I have used the 12.5mm Docter a few times but have never had one in my mitts long enough to do a full A/B comparison against all the competition. Between us we can provide plenty of eyepieces for comparison, I have a 12mm Nagler T4, a 13mm ETHOS, a 14mm Pentax XW and a 12.5mm UO HD orthoscopic. You have a 13mm Vixen LVW at least, plus others probably.
I have a couple of premium Newtonians and you have a couple of premium APO refractors. Someone would probably be able to turn up with a big SCT; but I think that might only make such a fine eyepiece squeal in pain as it came out of a newt or refractor focuser and fell into a big cat eye.
Actually Matt I am sure between the two of us we can do an excellent job of conducting a full review on Col's new eyepiece for him. I have used the 12.5mm Docter a few times but have never had one in my mitts long enough to do a full A/B comparison against all the competition. Between us we can provide plenty of eyepieces for comparison, I have a 12mm Nagler T4, a 13mm ETHOS, a 14mm Pentax XW and a 12.5mm UO HD orthoscopic. You have a 13mm Vixen LVW at least, plus others probably.
I have a couple of premium Newtonians and you have a couple of premium APO refractors. Someone would probably be able to turn up with a big SCT; but I think that might only make such a fine eyepiece squeal in pain as it came out of a newt or refractor focuser and fell into a big cat eye.
Cheers,
John B
I like the way you think John ! Yes I can come up with a few options to compare the Doc to.
Someone would probably be able to turn up with a big SCT; but I think that might only make such a fine eyepiece squeal in pain as it came out of a newt or refractor focuser and fell into a big cat eye.
I'll volunteer to put that to the test who wants to give me a big premium newt?
....it's almost here.......
... did you now .....!!
