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[Pinac]

A Brief Comparative Review of the Oberwerk 20x65 ED Deluxe

 

The new Oberwerk 20x65 Deluxe binocular, available since about 6 months in the US and 2 months in Europe, came into a market in which most other 20x binoculars have the configuration 20x80, surrounded by a very few others in sizes 20x70, 20x60 and 20x56.

My initial thought was to broadly compare the “Oberwerk” with those other 20x binoculars which are available to me for side-by-sides (the only way I am capable to really compare stuff). These are:
 

20x80
Celestron Skymaster
Celestron SkymasterPro
Omegon Argus
Opticron Oregon
Steiner Observer

APM MS 20x80 ED APO
 

20x70
APM MS ED APO
Lunt Engineering MS
 

20x60
Pentax SP WP
 

20x56
Nikon Monarch 5
 

I even thought about adding the Nikon 18x70 IF WP WF to the list.
 

However, initial reviews made it quickly clear that the field was too broad for meaningful comparisons – optically, there are “worlds” between a Celestron Skymaster and an APM ED, and a smaller selection with instruments of similar performance levels seemed more appropriate.

In addition, the Nikon 18x70 is a very, very nice binocular per se, but with its price 2x as high as the APM 20x80 ED and 3x the price of the Oberwerk 20x65, I thought I could assume that the interest in the forum might be in a more “like-for-like” comparison, so I could put the very expensive (and non-ED, non-flat-field) Nikon aside.
 

Plus, the broader 20x80 universe had already been a subject of discussion not too long ago here, see:
https://www.cloudyni...view/?p=8393024

 

Starting to review some of the same binoculars again, I realized that there was like a "gap" in optical performance between the binoculars featuring ED glass and the non-ED ones. I don’t think this can be generalized, i.e. that non-ED binos would be generally worse than the ED ones; it just seems that the ED ones in the group happen to also be the better binoculars than the others.
 

All of this led me to pick and compare only 3 instruments for this review (see next post). Therefore, just the following brief remarks about the other 20x binos not included in the review.

First of all, since I already got these data, a table with some relevant data on all those binos (see Appendix 1).

 

A note regarding the column under the heading “Prices”: for some of the binoculars, more or less similar prices can be found on many different websites, whereas for others, prices vary greatly. So I tried to pick midpoint prices that made some sense to me, and I mentioned price ranges where I could not figure out what was going on.

 

Then:

Celestron Skymaster / SkymasterPro, Omegon Argus, Opticron Oregon, Steiner Observer:

see also
https://www.cloudyni...view/?p=8393024

 

where they were discussed not too long ago.

 

Lunt MS 20x70: this is the non-ED predecessor of the APM 20x70 ED AP; optically quite similar in many respects, and still a very nice bino, but with more pronounced CA, lower contrast and a noticeable yellow tint, compared to the ED version.
 

Pentax 20x60: the clearly narrower FOV in the Pentax compared to the other 20x binos is striking and clear negative point in my view; central sharpness is okay, peripheral sharpness acceptable, but noticeable CA appears even slightly off-axis (I am generally not too sensitive to CA). The pro’s of the Pentax are robustness, compactness and light weight, and for certain usages the central focus.
 

Nikon Monarch 20x56: the smallest of all 20x binos I know, not even half the length of the Oberwerk. Optically and mechanically still quite a decent bino in my eyes, but don’t expect miracles from a 20x binocular in such a compact body. Like the Pentax, a very nice and portable “grab-and go” instrument with central focus.

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Edited by Pinac, 30 March 2019 - 04:35 PM.

[Pinac]

A FIRST LOOK AT THE OBERWERK 20X65 ED DELUXE

The following are the three instruments compared in this brief review:
 

- Oberwerk 20x65 ED Deluxe
- APM MS 20x80 ED APO
- APM MS 20x70 ED APO

 

So, two APMs against one Oberwerk (but as you will see, it wasn't too unfair, the Oberwerk fought quite well).

 

Since Oberwerk mentions on their website that the 20x65 is “…. our take on the legendary, but discontinued, Takahashi 22×60 …., I was not expecting a short, compact instrument, but the length of the 20x65 still surprised me, see it next to the APM 20x80 (see pic).
 

The following link kindly provided by forum member terraclarke recently shows nice pictures of the same instrument as the Oberwerk 20x65, but apparently sold under a private label brand-name “Forrester”:

https://www.aliexpre...2905408486.html

 

The 20x65 comes well finished, the back part lightly rubber armored and in military green and with nice haptics, the front end in black painted aluminium. It comes with a sturdy pre-installed center mount that allows easy balancing when tripod mounted (the APM has a similar mount on their 100 model, but not on the 70 and 80).

EDIT: See Rich‘s post further down, mentioning that the APM‘s now also feature a hinge axis extension rod.

 

Everything mechanical works well and smooth. The external diameter of the eyepieces  is 45mm, 5mm less than those on the APMs (both the 70 and 80 appear to have identical eyepiece dimensions), which makes it slightly easier for people with narrow IPD to fit their nose in between. The diameter of the eye lens, however, is only 0.5mm apart, 21.5mm in the Oberwerk, 22mm in the APMs.

The folded down eyecups on the Oberwerk reveal a filter thread on which usual astro or other eyepiece filters can be fitted (see pic). That is a very nice feature!

 

Eye placement on the eyepieces is comfortable; I prefer the folded down position of the eyecups actually to comfortably see the entire field of view (same on the APMs).

 

The “official” eye relief spec for both APMs is 16mm, for the Oberwerk it’s 18mm, but all of these are obviously measured form the surface of the eye lens.
Measuring the eye relief myself (effective, i.e. measured from the rim of the folded eyecup) with the dynameter, I get about 11mm for the Oberwerk; the APM 70 has about 2mm more, the APM 80 3mm more. I observe without eye glasses and have no problems with the Oberwerk, but the 11mm might just be a bit “tight” for eyeglass wearers (?); to be checked further.

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Edited by Pinac, 30 March 2019 - 04:42 PM.

[Pinac]

In the 20x65 as well as in the two APMs, the area around the exit pupil looks nothing like the ideal “round white spot surrounded by black”; in all three of them, quite a lot of lighted structures and more or less false pupils appear, maybe slightly more pronounced in the Oberwerk than in the APMs (see pics). There is only little vignetting, again in all three more or less the same.
 

True aperture: according to APM, their 70 ED and 80 ED operate at full aperture. The same is true for the 20x65, according to Oberwerk: in the list of technical data for the roughly 20 binos mentioned on the website, only 5 are said to operate at 100 % aperture (this has been the subject of a separate discussion here on CN), and the 20x65 is one of them (I might test this at some point myself, just to sleep well … ;-)

The reviewed samples of all three models appeared well collimated.

 

Below:

1st image APM 20x70, 2nd APM 20x80, 3rd Oberwerk

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Edited by Pinac, 30 March 2019 - 11:06 AM.

[Pinac]

OBSERVING DAY AND NIGHT
 

Putting the Oberwerk 20x65 ED Deluxe, the APM MS 20x70 ED APO and the APM MS 20x80 ED APO side-by-side on tripods (see pic), the following were my eight main points of interest:
 

- Field of view
- Image brightness
- Central sharpness / Contrast
- Peripheral sharpness
- Chromatic aberration
- Color fidelity
- Stray-light control
- Ghost images

 

Field of View
3.3 degrees in the APM 20x70 and 20x80, 3.2 in the Oberwerk 20x65. Translated into m/1000m, that is 58m vs 56m, so quite a small difference. However, in the field, I found the difference noticeable, both at daytime and at night. In the APMs, the Pleiades appear surrounded by slightly more nightsky, which makes them stand out a bit more nicely, than in the Oberwerk. Not a huge difference, but a difference.

 

Image brightness
During the day, I could not make out any difference in brightness between the three contenders. The Oberwerk with its 65mm lenses appears as bright as the APM with 80mm. The brightness of the Oberwerk is further “enhanced” by its absence of any color tint; white appears very white (see paragraph on “color fidelity”).
At night, when the eye pupils are dilated, the APM 20x80 shows a slightly brighter image of the nightsky than the Oberwerk. The latter is more or less at par with the APM 20x70. Of course, a brighter nightsky may generally present both advantages and disadvantages. However, here the APM 20x80 also seems to show slightly more faint stars in open clusters such as M45, or at least those faint stars seem a nuance brighter than in the Oberwerk 20x65.

 

Central sharpness / contrast
No substantial difference among all three instruments during the day. The Oberwerk gives crisp, contrasty images of e.g. a cemented wall covered with a rough paint, or of structured pieces of bark on trees, and neither of the APMs provides more or better detail.
At night, nice point like stars in the Oberwerk, both the brighter ones and the faint ones. M42 exhibits quite a bit of structure within the nebulous area, with 3 of the 4 trapezium stars immediately identifiable in the Oberwerk, the 4th one at least guessable (a lot depends on eyesight here as well). The Oberwerk shows the nebula slightly less bright than the APM 20x80, but not with significantly less detail, since the sky background appears a bit brighter in the APM. The image of the APM 20x70 appears comparable to the one of the Oberwerk, there is little difference, if any, in terms of brightness or contrast, at least for my eyes.
As mentioned, the narrower FOV makes the Pleiades appear slightly less brilliant in the Oberwerk than in the two APMs, not much, but enough to recognize a difference.

 

Peripheral sharpness
Day and night, edge sharpness is really good in the Oberwerk. Point-like stars throughout most of the image. Blur starts to appear only very close to the edge of the image. There, and only there at the very edge, sharpness in the Oberwerk appears slightly worse than in the two APMs. After much comparing and reviewing, I found that until about 80% out from the image center towards the edge, the image of the Oberwerk seems actually slightly sharper than that of the APMs. Again, not talking about huge differences, more like nuances. In essence, edge sharpness is really good in all three.

 

Chromatic aberration
This is the area where the Oberwerk clearly rules, in my view. I could not provoke noticeable color fringes in the central parts of the image, neither on crane arms against a bright sky background, nor on tree branches, nor on shiny objects. I do not remember having seen better CA correction in a high magnification bino. Moving toward the periphery of the image, you can provoke color fringes if you try hard enough, but correction appears again very good. The two APMs are both not bad in this discipline, but both show clearly more color than the Oberwerk. The difference is immediately recognizable. Presumably, the very long body of the Obie and slower focal ratio result per se in less chromatic aberration (nothing gets around physics laws)?
At night, CA is not a big issue unless one observes bright objects, such as the moon, or perhaps bright planets such as Jupiter. Observing the moon without essentially any of the usual color fringes at the edge of the disk is a real pleasure in the Oberwerk. The APMs are themselves quite color free already, but the Oberwerk is a further step up in my view.

 

Color fidelity
Right when I started observing with the Oberwerk 20x65, its image appeared “bright and white”. The paper test confirms that the image is “whiter” than in the APMs, which themselves show quite little color tint; but compared to the Oberwerk, the APM 20x70 and even more the 20x80 appear to have a slightly warmer color tone in their image. This is definitely true for daylight observations. At night, the difference is less apparent; all three instruments show nice color nuances on the different types of stars.

 

Stray-light control
During the day, observing against a low standing sun, even with sunlight directly shining onto the front lenses, the Oberwerk and both APMs exhibited various types and all sorts of passing reflections when panning the binocular, but observation remained always possible and the image never “faded out” or got covered with a glaring veil. So, overall satisfactory performance, and I could not determine winners or losers.
The same is true at night. In the Oberwerk like in the APMs, you can get the occasional reflection from bright objects such as the moon; e.g., when panning the binocular around the moon disk, keeping it just outside the field of view. Nothing major, though, and not as intrusive as in certain other instruments. Observation of objects relatively close to the moon remains possible.

 

Ghost images
These (more or less sharp images of bright objects caused by reflections on air-glass transitions) are another form of stray-light. As far as I can say, they seem not an issue in either the APMs or the Oberwerk.

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Edited by Pinac, 30 March 2019 - 11:12 AM.

[Pinac]

Summarizing my impressions, these would be conclusions in form of a table (there is a total of 6 points in each category, the best performing binocular gets 3 points, the next best 2, the last one 1; in case several binoculars rank equal, their scores are averaged), see:
Appendix 2.

 

The new Oberwerk performs well in my view – if I take into consideration that the Oberwerk is almost 45% cheaper than the APM 80 and almost 30% cheaper than the APM 70, it performs very well indeed.

 

Opinions from other users, especially those who disagree with my “findings”, would be very welcome.

 

Pinac

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[Rich V.]

Thanks for the well presented review of these binos, Pinac.  I'm sure this will be helpful to many that are considering such a bino.

 

The 20x65s look like a very close cousin of the long WO 22x70s of yesteryear.  A bit lighter weight, though!  No retracting dew shields on the Obies from what I see.

 

My 70mm APM EDs have the newer mounting arrangement that's similar to the Oberwerk with the hinge axis extension rod for support.  Your APMs are the original iteration.  I'd expect all newer APMs would arrive with this newer mounting setup.

 

Like the WOs, it appears to be a trade-off between greater size/bulk of the bino vs. improved color correction.

 

Rich

Edited by Rich V., 30 March 2019 - 12:25 PM.

[ButterFly]

Thank you for this much needed review.

 

How is the depth of field on the Obie's vs the APMs?  That focal ratio looks huge.  For daytime use, the extended hyperfocal distance is a huge benefit with ED glass.

 

Have you noticed much sensitivity to eye placement for CA based on centering or eye relief in any?

[Pinac]

Thank you for this much needed review.

 

How is the depth of field on the Obie's vs the APMs?  That focal ratio looks huge.  For daytime use, the extended hyperfocal distance is a huge benefit with ED glass.

 

Have you noticed much sensitivity to eye placement for CA based on centering or eye relief in any?

 

Sorry, I haven't checked hyperfocal distance, nor minimum focus. I use all three binos almost exclusively for astro.

Thanks for raising the question about eye placement. This seems to be a non-issue with the Obie, even with eye placement slighty off-axis there is not much of a difference in CA in my experience.

[Mad Matt]

👍👍 Awesome review Pinac!... as always 😉😁👍

I’ve been thinking about getting the APM 20x70 as a grab and go setup but maybe I should go for the Oberwerk instead... sometimes I hate you! 😜😁😎

Edited by Mad Matt, 30 March 2019 - 12:50 PM.

[Pinac]

Only sometimes??

 

Awesome review Pinac!... as always

I’ve been thinking about getting the APM 20x70 as a grab and go setup but maybe I should go for the Oberwerk instead... sometimes I hate you!

 

Only sometimes? 

[Mad Matt]

Only sometimes??

 

 

Only sometimes? 

I only hate you sometimes... my wife? now that is another story    

[Mike G.]

Thanks for the great review!  An interesting entry into this niche market. 

[Terra Nova]

Wonderful review, very through! I like the three you narrowed it down to for your comparison. I still have not made a purchase, as I planned on waiting for warmer weather. Your comparison has brought me back to placing the Obie 20x65EDs at the top of my list.

[Rich V.]

If one were interested in a mounted binocular "spotter" for observing wildlife, I'd think a bino like the Obie 20x65 would be ideal.  While ED binos are nice for astronomy, it's in daytime use that the optics really shine, IMO.

 

The longer f6 ED binos like these Obie 20x65s and the WO 22x70s are clearly a step up in CA control over the others.  You really see it when eagle watching in a bright, snowy landscape, for example.  

 

Rich

[KennyJ]

Pinac,

 

Thank you for a very well presented three - way review, which put me in mind of the way the great Dr.Holger Merlitz goes about such comparisons.

 

Sadly, what had been quite a keen interest in this particular model since first becoming aware of it, was shattered as soon as I realised the effective eye-relief is only around 11mm -- which is a very important 5mm too short for me.

 

Kenny

[dave85374]

I have been looking at purchasing one of the three ED 20x bino's you are comparing, especially the Oberwerk (American made and less expensive to boot).  The APM's have always been touted for their views and Oberwerk always gets talked about for their optics and customer service.  So I have a couple of questions for you.

 

1. Have you had a chance to examine the aperture yet to see if it is operating at 100% 65mm yet.  You said you wanted to check this out yourself since you were using Oberwerk's website numbers.  You seem to like what you have seen, but am wondering what your thoughts would be if it is somewhat less than 65mm.

 

2.  Being new to binoculars, do you think the eye relief of 11mm is too tight for eyeglass wearers?  I prefer to view without glasses, but if I were at a star party I would rather view with glasses so others could view what I see with my corrected eyesight for easier viewing with their proper eyesight so there wouldn't be the need for others to refocus all the time.  Also for myself using glasses for viewing would definitely make it easier looking at star charts and other material rather than having to keep putting them on and taking them off.

[Rich V.]

 

I have been looking at purchasing one of the three ED 20x bino's you are comparing, especially the Oberwerk (American made and less expensive to boot).  The APM's have always been touted for their views and Oberwerk always gets talked about for their optics and customer service.  So I have a couple of questions for you.

Hello, Dave, welcome to Binoculars.

 

Kevin at Oberwerk has a good reputation among bino enthusiasts; he's been in the bino business for a long time and was instrumental in making "big binoculars" a popular alternative as astronomy instruments.  I should point out that no consumer binoculars are "American made" any longer.  Most larger binos like those discussed here are of Chinese origin but there are still some expensive premium binos from Japan and Europe.  Nikon, Fujinion, Docter and Steiner come to mind.

 

Regarding effective aperture, Kevin's listed the binoculars he sells on a spec page that shows the effective aperture of all the models he sells; the 20x65s are listed as 100%.  Most higher end Porros are now operating at their full aperture or very close but LW models do not generally.

 

https://oberwerk.com...mparison-chart/

 

Eye relief gets tricky; most claimed ER doesn't take into account the recess of the eye lens inside the eyepiece assy.  It's usually at least 2-3mms, sometimes much more.  11mm effective is generally very marginal for eyeglass use.  Usually 16-18mm effective will work with most but it really depends on the individual.  Thin (-) eyeglasses with lenses held close to the eye may work best while thick (+) lenses are more troublesome.  11mm ER with my strong + prescription eyeglasses (my Fujinon and WO 70mms, for example) only show about 50% of the FOV so I view with contact lenses or no corrective lenses at all.

 

If ER is really important to you, a 16x70ED like the APM provides greater ER than the 20x model;  I measured a bit over 18mm effective.  It also provides +/- 10 diopters of focus either side of the "0" position.

 

Rich

[dave85374]

Since I am new to binocular use I don't know how much eye relief I need.  My optometrist says my readings are +2 right eye and +3.5 in the left eye.  I do not have "coke bottle" thick lenses.  Any idea what I would need based on these readings?  I really would prefer 20x more than 16x, although the FOV on the 16x would definitely be larger.

[jcj380]

Since I am new to binocular use I don't know how much eye relief I need.  My optometrist says my readings are +2 right eye and +3.5 in the left eye.  I do not have "coke bottle" thick lenses.  Any idea what I would need based on these readings?  I really would prefer 20x more than 16x, although the FOV on the 16x would definitely be larger.

I don't think prescription has any effect on ER needed.  More like how much ER do you need to wear your glasses comfortably when observing.

Edited by jcj380, 13 June 2019 - 07:40 AM.

[Rich V.]

The type of correction does make a difference; + diopter lenses are convex lenses that are thicker in the middle and eat up ER.  That said, at only +2 and +3.5D, Dave's are not particularly strong and eyeglass frame design and facial features will dictate whether the bino's ER will work more than anything.  Be sure to roll the eyepiece's rubber eyecups back for best results. 

 

There's plenty of focus range for him to use the binos without eyeglasses if he is only far-sighted with no astigmatism.

 

Take the time to carefully consider a mount for the binos as well.  A poorly matched mount will spoil an otherwise great bino.

 

Trying before buying is always best if possible.  Otherwise, make sure you buy from a vendor with a good return policy.  

 

Rich

[dave85374]

Thanks for the reply's.  I plan to go with either a parallelogram (UMB) from Oberwerk with their 5000 tripod which is out of stock until late July or with the Orion Monster Parallelogram Mount set up.  The cost is the same when you take into account the shipping cost.  Would definitely prefer the one from Oberwerk though.

[Rich V.]

A relatively inexpensive (under $100.) aluminum surveyor's tripod is a good match for the Farpoint p-gram.  Much less prone to oscillate under the load than a tripod like the 5000.  I've tried it both ways and the surveyor tripod works best.

 

Tall photo tripods are handy and have a place as well for binos but are not the best platform for a p-gram.  Take a 10# p-gram with 10# of counterweight and add a 7# bino and you've already maxxed out a 26# rated photo tripod...

 

Rich

[dave85374]

Could you give me a site or URL for possibly getting one of these aluminum surveyor's tripod?

[Rich V.]

Could you give me a site or URL for possibly getting one of these aluminum surveyor's tripod?

Something like this one or similar:

 

https://www.amazon.c...=gateway&sr=8-3

 

Make sure you get the 5/8"-11 post adapter for the p-gram.  Also make sure you get the "swing hinge" option if you get the Farpoint.  You'll need that if you want to view from a zero gravity recliner which I highly recommend.

 

Rich

Edited by Rich V., 13 June 2019 - 01:32 PM.

[Pinac]

.....

.....

 

1. Have you had a chance to examine the aperture yet to see if it is operating at 100% 65mm yet. .....

.....

 

2.  Being new to binoculars, do you think the eye relief of 11mm is too tight for eyeglass wearers?  .....

.....

.....

 

ad 1.

Yes, they operate at full aperture (see pic).

 

ad 2.

I have to disappoint you - not a chance with glasses. I tried several pairs, very slim ones and some thicker reading glasses, but did not find one that would let me see the entire FOV with my glasses on.

The problem is that folding down the rubber eyecups helps only partially, because the filter thread (which is in metal and part of the eyepiece itself) sticks slightly out beyond the folded down eyecup, so you cannot approach the eyelens any further than the rim of the thread.

So the 20x65 is unfortunately nothing for spectacle wearers

 

Pinac

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Edited by Pinac, 15 June 2019 - 09:45 AM.