Zen-Ray: Charles Optics Talk

The editor’s conclusion? “There’s a lot of value in this basic roof-prism binoculars”

here is the list

#1 Swarovision 10×42 $2754
#2 Weaver Super Slam 10.5×45 $1114
#3 Zeiss Conquest 10×56 $1499
#4 Bushnell Ultra-HD $300
#5 Vortex Viper R/T 10×50, $680
#6 Zen-Ray VISTA 10×42, $139
#7 Pentax DCF CS 8×42, $279
#8 Steiner C5 Predator 10×56 $1000
#9 Nikon Monarch ATB 10×42 $299
#10 Yukon Frontier 8×42 $180
#11 Cabela’s Alaskan Guide 8×42 $480
#12 Carson 3D 8×42 $290
#13 Celestron Nature 10×42 $120
#14 Minox BL 10×44, $499
#15 Alpen WINGS 10×42, $192

Roof  binoculars employ Schmidt-Pechan prisms to achieve image erection in a more compact platform.  Unlike Porro prism system, which can transmit light by lossless total internal reflection, Schmidt-Pechan prism relies on reflective coating on the non-TIR surface to minimize the loss.  Aluminum metallic coating has been commonly used in entry level binoculars. The next major step-up is silver prism coating, which allows no more than 94% reflectivity.  To achieve almost lossless light path, dielectric prism coating is used by Zen-Ray’s ZEN ED2 and the newest ZRS HD binoculars.  A flawlessly executed dielectric coating, like the ones used in ZEN ED2/ZRS HD, offers many benefits over conventional metallic coatings.

First of all, dielectric coating presents a flat response curve with the wavelength, therefore, allows a more neutral color display. By looking at the graph above, one can see that the silver prism coating shows rapid fall-off of tranmission at short wavelength.  As a result, the image often presents warmish color tint, in addition to the brightness degradation.

With close to 99% light reflection over the full visible spectrum, dielectric prism allows at least 5-7% brightness improvement over the best metallic coating.   This extra illumination improvement is critical to enhancing the overall user experience under extreme low light condition.

No, it does not look anything close to the American Goldfinch shown in the picture above. If you are not too patience, scroll down to the end of this blog to get a glimpse of new VISTA binoculars

In 2010, we have redesigned the VISTA line for birders, hunters in mind with some substantial uppgrades. VISTA was designed for general viewing purpose that can double as equipment for birding, whale watching, and hunting. Because of its sub $150 price point and excellent optical performance, 2009VISTA has been very popular among birders. Over the last few months, we have been contemplating for areas of improvement. Essentially, it was narrowed to several key components that will be incorporated into 2010 model.

 1. Sharpness: a premium glass was choosen to replace current material so we can yield a higher resolution and improves the overall sharpness.

2. Brightness: 2010 VISTA features Ultra high reflectivity Silver prism coating that increases light tranmission rate significantly.  As a result, it is well suited for use long after sunset.  We also increase the image contrast performance substantially with phase correction coating.

3. Field of view: the feedbacks from some customers encourgage us to increase the FOV of VISTA binoculars. You have spoken and we have listened. The new VISTA will increase field of view by 25 feet 10x model and over 10 ft for 8x model.

4. Increase the ocular lens effective diameter to 22mm. That alone significantly improves the low light performance of VISTA binoculars.

5. Now VISTA is full waterproof with Argon gas charged to prevent internal fogging. Its performance is much improved over previous N2 filled model.

Here is a sneak preview of Zen-Ray VISTA 2010 model. It will be available for sale now with delivery date of Feb 1, 2010.  If you have owned a pair of 2009 Model, I would encourage to compare it side by side with 2010 VISTA.  The performance improvement is quite obvious. 

Oh, before I forget, the online store is taking pre-order now. http://www.zen-ray.com/store

A well respected optical engineer, Ilya Koshkin, just published his review of 7×36 ED2 binoculars. Be sure to check it out.

http://www.opticstalk.com/forum_posts.asp?TID=21463

Have a nice weekend

I just got off a meeting with our production engineering.  The 10×43/7×36 ED2 are on schedule to deliver at beginning of week 11/23. Thank you very much for your patience.

Holger Merlitz shared his experience with improved ZEN ED2 7×36 in his blog.

In summary,  ”The new binocular does now exhibit a very well balanced performance pattern and can be regarded to play inside the upper middle class league, superior to the…”   Well, you should read his full review here http://www.holgermerlitz.de/zen7×36.html

On another note, John Johnston sent up his review article for the 10×43 ZEN ED binoculars. We got the permission from publisher to link the pdf version on our website.

 http://www.zen-ray.com/Zen-review.pdf

We have been contacted by many of our customers about the availability of ZEN ED2 7×36 as we have previously sold out them well before we even had them in stock.  The good news is that we were able to prioritize our future production schedule to hopefully get some improved 7×36ED2 back to our customers’ hands in the 2nd half of the November.

When 7×36 ED2 was first released, it was immediately recognized for its truly amazing wide FOV (9.1degree), ultra sharp resolution,  excellent CA control, deep depth of field, and true color display without any color bias.
From the feedback we received, we also recognized that a small percentage of users were affected by an internal glaring issue.  Although it only seems to affect a small group of users, we took it as an opportunity to further enhance the performance of this particular model. We have gone through an extensive examination of the binoculars to look for the cause of the glare.

We learned that the combination of smaller barrel size of the 36mm and larger optical cone of 7x made the internal reflection easier to detect than its larger 43mm counterparts. We also employed an oversized prism system and ocular lens system to maximize the resolution and brightness. These two features make glare control much more challenging.  Some users may still experience the glare because of eye pupil size or how they hold the binoculars relative to their eyes.

We have re-engineered the optical system, without compromising the existing performance, by incorporating additional eyepiece baffling and making another internal baffle less reflective. We feel those changes are the basis of the problem and hope they will rectify the main cause of this glare
issue.

First I want to apologize to many of the loyal Zen-Ray customers since we don’t have any 2008 SUMMIT binoculars to fullfil the current orders.  It is quite a disappointment to our customers, as well as to us.  I am also excited about the prospect of new SUMMIT model we are about to roll out in December this year.  The project to re-design 2009 Zen-Ray SUMMIT is internally coded as “tigertown”

As we all have come to appreciate the superb optical quality of SUMMIT binoculars, there is always room to improve.  Without throwing  too many technical jargons into my blogs, I would like to highlight several significant change on the new SUMMIT prototype (Yes, we finished prototype, yet dress the binoculars with the final finishing. It will be a busy summer and fall for everyone involved in the “tigertown” project).

The biggest accomplishment by the optical designer is to overcome the perennial  challenge facing all binoculars models under $1000: the edge to edge sharpness.   In addition, we choos the most expensive LANK optical glasses for two of the critical elements.  It’s a rather elaborated system: 5 lenses for eyepiece, 3 lenses for objective lens, additional lenses for internal focusing.  So, we are talking about 20 pieces of glasses for both barrels.  That’s a lot of glasses. 

Every glass need to be applied by multi layered anti-reflection coating on both sides so we can achieve 99.5% transmission rate at each surface. Essentially, the engineers are facing the challenge to ensure the uniformity and quality of all 40 glass-to-air surfaces by employing state of the art grinding, polishing, and coating techniques.  As a result, the brightness of “Tigertown” is improved by at least 5% over the 2008 SUMMIT

In addition, we have fine-tuned the propriatary Silver ZROS (Zen-Ray Optic System) phase coating  on the BAK4 prisms to eliminate the phase shift of spectrum so a vivid natural image can be rendered through the binoculars. As a result, an effortless viewing experience is achieved through this innovation.

That’s not all. There are many more mechanical enhancements as well for project tigertown. I was allowed to chat with engineers and disclose few things that are in the work.

1. The eyecup will have a silk smooth 4 stage(position) moving mechanism. This will allow users to set the eyecups height to their preferred positions. This has been a very favorite feature among people with or without eyeglasses

2. A diopter lock is embedded in the system so you never have to worry about losing the setting.

3. Tigertown is purged and charged with bone dry Argon noble gas and sealed with o-ring. It is 100% waterproof and fogproof. Although it is not intended to be used underwater, the binocular is rated for waterproof under 5 feet of wafer for 3min.  We choose Argon over traditional N2 gas because Ar is less diffusive than N2 and is less reactive than N2.  This makes it a ideal protective gas to create an inert ambient environment to protect the sensitive optical system

With all of above improvements, tigertown (2009 SUMMIT HD) will boast a significant leap forward for sharpness, brighness, distortion free and edge to edge uniformity.  The new binoculars will also see an FOV increase for 10x model from 304 ft/1000 yards to 315ft/1000 yards.  The minimal focus spec is tighened from 2.5meter to 2meter. 

I promise to write more about Tigertown (SUMMIT HD) in the coming months as more details about this exciting new products are getting closer to our customers’ hands.  After trying two pairs of 10×42 and 8×42 prototype, I can assure you that you will not be disappointed!   Stay tuned

Shawneen Finnegan and I paid an visit to Tualatin River NWR and Fern Hill Wetlands on Sunday 7/20/08.  Throughout the morning, there were tons of activities out there, almost like a paradise for photographing and digiscoping.  Shawneen impressed me a lot with her multi-dimensional skills in ID’ing the birds: call notes, song, flying pattern, shape, feeding habits. As an accomplished artist and world-renowned birder, authorr, Shawneen recounted the birds we have seen with her razor-sharp memory.  The list below was compiled by Shawneen.

edge and a second area nearby with more mud edge. Lots of young

swallows (my estimate is probably low) and quite a few juvenile

Spotted Sandpipers, with one group of four still mostly down-

covered. We spent a good deal of our time photographing/

digiscoping. All the ducks were in eclipse plumage (tis that time of

the year). Four very fluffy junior Spotted Sands were very

entertaining, already bobbing like the adults, though they had little

to no tails yet.

Number of species: 39

Canada Goose 12

Wood Duck 2

Gadwall 8

Mallard 20

Cinnamon Teal 5

Northern Shoveler 1

Northern Pintail 1

Green-winged Teal 1

Hooded Merganser 2

Ring-necked Pheasant 1

Great Blue Heron 8

Turkey Vulture 1

Northern Harrier 1

Red-tailed Hawk 2

Killdeer 6

Spotted Sandpiper 15

Greater Yellowlegs 3

Least Sandpiper 1

Vaux’s Swift 2

Belted Kingfisher 1

American Crow 2

Cliff Swallow 40

Barn Swallow 30

Black-capped Chickadee 2

White-breasted Nuthatch 1

American Robin 4

European Starling 2

Cedar Waxwing 5

Yellow Warbler 3

Common Yellowthroat 10

Spotted Towhee 1

Savannah Sparrow 5

Song Sparrow 4

White-crowned Sparrow 3

Lazuli Bunting 2

Red-winged Blackbird 75

Brown-headed Cowbird 2

House Finch 4

American Goldfinch 10

Location: Fernhill Wetlands

Observation date: 7/20/08

Number of species: 31

Canada Goose 10

Gadwall 4

Mallard 35

Great Blue Heron 5

Turkey Vulture 1

Red-tailed Hawk 2

Peregrine Falcon 1

Killdeer 10

Spotted Sandpiper 2

Greater Yellowlegs 3

Western Sandpiper 1

Least Sandpiper 12

Long-billed Dowitcher 3

Mourning Dove 2

Vaux’s Swift 1

Downy Woodpecker 1

Western Wood-Pewee 1

Tree Swallow 50

Northern Rough-winged Swallow 2

Barn Swallow 25

Black-capped Chickadee 2

Marsh Wren 10

European Starling 2

Cedar Waxwing 8

Common Yellowthroat 12

Savannah Sparrow 1

Song Sparrow 8

Black-headed Grosbeak 2

Red-winged Blackbird 25

Brown-headed Cowbird 6

House Finch 4

Portland Audubon Society’s nature’s sanctuary has been a magnet for bird watchers, hikers. Last time I went was several months ago.  This afternoon, I dropped a friend off in downtown Portland and decided to pay a long overdue visit to the sanctuary on my way back.

It is a really hot summer day, by Oregon standard. The temperature reading from car is 90 degree outside.  I walked out of car at parking lot. It didn’t feel that hot at all. I guess the tall trees provide the extra cover and shades to keep the park cool. 

I went straight into the nature store building and met volunteer Rossie.  She was very kind and patient. She went through a long list of birds she has seen that came to visit the feeder throughout the day.  As we spoke, two black-headed grosbeaks flew in. I took out my camera and shot several pictures.  The traffic was quite heavy. In a few short minutes, I have counted: grosbeaks, black-capped chickadees, song sparrow, Dark-eyed Junco.

After I am satisfied with my “shooting spree”, I went into the store.  There was a whole wall of birding books.  I counted 6 different books that are written specifically for Oregon.  I have never carefully examined their collection before.  It was really an eye openning experience.  Trust me, if you need your next birding book, skip Borders, Barnes&Noble, go straight to Nature store. You will find almost anything that is related to birding. 

After visiting store, I met a couple of volunteers to snap a few pictures of Turkey vulture and Peregrine Falcon.