A Work Commenced December 6 2022

Without a doubt, one of the great highlights of my year was being introduced to the Nikon E series of Japanese-made Porro prism binoculars. Collectively these instruments have utterly transformed my opinion on the relative merits of roof over Porro prism designs, to such an extent that I’ve come out strongly in favour of the latter for daytime and night time use(using a 10 x 50 model). In this blog, I wish to discuss these fine optical instruments and what I’ve been learning about them in field use. It has also led me to carry out an investigation as to how well they perform in cold winter weather use, which will be ongoing.

First of all, I have been overjoyed by the images both these binoculars have served up in a variety of lighting conditions. The Nikon E II 8 x 30, in particular, remains my firm favourite, where it never ceases to inspire in every conceivable way. Its older cousin, a newly restored mid-1990s vintage Nikon E 10 x 35 has also impressed me as a longer range, wide-angle instrument in a lightweight, portable package.

The Move to Shorter Neck Straps

One common gripe among some Nikon E II 8 x 30 users is its ‘hang problem.’ Though I never saw much of an issue with this personally, I hit on a neat solution when I swapped out the high-quality neck strap attending the E II with the 10 x 35 strap, which was significantly shorter. What did that do? Well, by resting the instrument higher on my chest, it caused the little 8 x 30 ocular lenses to orient themselves with a much smaller angle to the vertical, with the result that it now sits much more upright on my chest.

Indeed, I’ve also shortened the neck strap on the 10 x 35 so that it too sits higher on my chest, reducing the amplitude of oscillatory motion significantly. This measure will reduce shock impact in the long term, especially when negotiating walls and fences on my walks through the Scottish countryside, reducing the risk of accidental knocks and bumps and so minimising the possibility of the optics becoming misaligned over time.

The Effects of Partially Folding Down the Rubber Eyecups on the 10 x 35 

One afternoon, while glassing the landscape with my 10 x 35, I realised something was off. Specifically, unlike the 8 x 30, which showed me the beautiful field stops of the binocular with its amazing 8.8 degree field, I realised I wasn’t seeing the same on the 10 x 35. But that was easily solved by partially folding down the rubber eyecups(see the first image presented above) on the instrument, which finally enabled my eyes to engage with the full 6.6 degree field the instrument serves up. Now the field stops are beautifully apparent, and as a result I’ve come to more greatly appreciate just how wonderful it is to view the world at 10x in an expansive 6.6 degree field. Let’s face it, even with the march of time, having such a large field at 10x is still rather special. And while its newer incarnation – the venerable E II 10 x 35 – sports one of the widest fields for a 10x glass currently available(7.0 angular degrees), the field of view on the Nikon E only represents a very modest 12.5 per cent  truncation; not enough to justify acquiring the E II 10 x 35 in my opinion. The view through the Nikon E 10 x 35 is highly immersive, feeling wider than it really is owing to the excellent off-axis performance of the instrument.

The other improvement I’ve noted by partially turning down the eye cups on the 10 x 35 is significantly better glare suppression. I learned this while using a few roof prism models, most especially the Vortex Diamondback HD series, when I noted that moving the eyecup down one notch greatly improved their control over glare. The 10 x 35 now yields comparable performance to the E II 8 x 30 in this regard, which has excellent glare suppression properties.

Ongoing Cold Weather Experiments with the Nikon Porros

Test everything, Hold fast to what is good

1 Thessalonians 5:21

My exchanges on Birdforum on the alleged weakness of the Nikon E Porros in regard to not being waterproof or fog proof, left me puzzled. I asked what I felt was a completely legitimate question:

“What did folk do before the advent of full waterproofing and nitrogen gas purging?”

Were there no birders before Steiner introduced the first fog proof binocular back in 1973?

The response I got was rather telling. Only a single person(Brock) eventually gave an answer of sorts, which indicated to me that not a great deal of thought was put into this issue. Instead I got rather glib responses like, “folk moved with the times and just bought waterproof instruments.”

That wasn’t good enough for me. Several generations of birders got on just fine before such an issue was “solved.”I perceived an altogether timorous culture of individuals who simply bought into the ‘roof prism solution.’

So how did they do it? And more importantly, what could I do about it?

 I wanted to find workable solutions.

And this led me to initiate an investigation into how effective simple, interventive measures could make to keeping such instruments fog free, both internally and externally, while glassing in cold and damp conditions.

My first approach was to construct proper storage containers for my non-waterproof Nikons. Theses comprised of simple Tupperware plastic containers filled with silica gel desiccant that were both air and water tight. You can see one such arrangement in the photograph below:

My plan was to simply leave the empty Sarcophagus in a cool, dry, unheated outhouse before venturing out into the cold and humid air. Such an outhouse would be at most just a couple of degrees higher than the outside air. I would wear gloves to minimise the transfer of heat from my hands to the Magnesium alloy chassis of the binoculars. And immediately after my return from my glassing excursions, I would then place the instruments inside their containers before bringing them into a cool back lobby. Then, after a spell there, I would return them to room temperature.

Taking advantage of a cold snap, which would endure for at least a few weeks from the beginning of December 2022, I began daily experiments, taking some notes on ambient temperature, wind speed and humidity, as well as the duration of my walks. The reader will note that I did not use any anti-fogging agent during the course of these experiments. My results are published below:

Date: December 4, 8 x 30

Temperature: +4C

Wind: 11mph NE

Humidity: 70%

Time outside: 11:30-12:35 GMT

Result: Recovering from a head cold, some perspiration from my head caused the ocular lenses to fog up once externally. It dispersed within seconds. Otherwise, no problems. No internal or external fogging.

Date: December 5,  10 x 35

Temperature: +4C

Time Outside: 12:25-13:35

Wind: 8mph N

Humidity: 70%

Result: No internal or external fogging observed.

Date: December 6 , 10 x 35

Temperature: +3C

Humidity: 65%

Wind: 5mph N

Time Outside: 12:45-14:10

Result: No external or internal fogging observed.

Date: December 7, 8 x 30

Time: 11:05 – 1230

Temperature: +2C

Humidity: 84%

Wind: 6mph NW

Result: No internal or external fogging observed

Date: December 8, 8 x 30

Time: 11:15-12:30

Temperature: -1C

Humidity: 73%

Wind: 6mph N

Result: Some occasional fogging on right ocular lens, quickly dispersed. No fogging internally or externally observed when placed back in container.

Date: December 9, 10 x 35

Time: 12:30 – 13:40

Temperature: 0C

Humidity: 78%

Wind: 6mph NW

Result: No internal or external fogging observed.

Date: December 10, 8 x 30

Time: 12:45-14:10

Temperature:: +2C

Humidity: 81%

Wind: 6mph N

Result: No internal or external fogging observed.

Date: December 11, 10 x 35

Time: 12:55-14:05

Temperature: 0C

Humidity: 70%

Wind: 8mph NW

Result: No internal or external fogging observed.

Date: December 12, 8 x 30:

Time: 11:55-13:10

Temperature: -3C

Humidity: 88 %

Wind: None

Result: Right ocular fogged up a few times but dispersed rapidly, otherwise no internal or external fogging observed.

Date: December 13, 10 x 35

Time: 11:55-13:10

Temperature: -4C

Humidity: 94%

Wind: None

Result: A couple of instances of fogging to ocular lenses, quickly dispersed, but otherwise no internal or external fogging observed.

Date: December 14, 8 x 30

Time: 1200:13:10

Temperature: -2C

Humidity: 82%

Wind: 11mph NW

Result: No internal or external fogging observed

Date: December 15, 10 x 35

Time: 12:05-13:15

Temperature: -1C

Humidity: 94%

Wind: 3mph NW

Result: No internal or external fogging observed.

Date: December 16, 8 x 30

Time: 13:45-14:45

Temperature: +3C

Humidity: 83%

Wind: 9mph SSW

Result: Exposed to sleet and light rain, visibility poor. Chassis covered with some precipitation and droplets also deposited on ocular lenses. Instrument & strap was dried externally with cotton towel and a lens cleaning cloth used to rub away precipitation on ocular lenses before returning it to its Tupperware container. No internal or external fogging observed.

Date: December 18, 10 x 35

Time: 10:55-12:10

Temperature: +2C

Humidity: 85%

Wind: 8mph ENE

Result: No internal or external fogging observed.

Date: December 19, 10 x 35

Time: 12:15- 13: 25

Temperature: +12C

Humidity: 91%

Wind: 16mph S

Results: No gloves worn, some intermittent light rain encountered greatly reducing visibility. Water on chassis and strap removed with a cotton towel. No fogging observed externally or internally.

Date: December 20, 8 x 30

Time: 13:10-1415

Temperature: +7C

Humidity: 72%

Wind: 16mph SW

Result: No gloves worn, encountered one brief rain shower on the road. Instrument dried with cotton towel before being returned to Tupperware container. No internal or external fogging observed.

Conclusions: This two-week +-long study, conducted over a long cold spell, as well as some drizzly days show that these non-waterproof Porro prism binoculars fare just fine, so long as some simple interventive measures are set in place like wearing gloves when the temperatures are low, and returning the instruments slowly to ambient temperature once returned to their desiccant filled Tupperware containers. Some fogging of the ocular lenses tends to occur on colder days with reduced wind, but that’s exactly the same for waterproof roof prism binoculars, as my parallel experiences attest to(data not shown).

The results contradict those who claim that Porro prism binoculars are only fair weather glasses. To you I say:

Lazy, Scaremongering Killjoys!

You’re not credible!

This is yet another manifestation of our current “Big Jessie” culture, where “safetyism” is taken to extremes.

Don’t be a snowflake, and don’t let anyone tell you you can’t use them in winter conditions for ordinary activities, including walks in the outdoors up to at least 90 minutes duration. 

These results will be apprised in my up-and-coming book.

Some Highlights from my Winter Glassing

I’ve been really spoiled by the views these two high-class Porros have generated during the painfully short days of a Scottish Winter. To make the most of the light, it pays to get out in the late morning or early afternoon, as after about 2pm local time, the Sun sinks below the hills greatly diminishing the quality of light available in the valley. Still, the low altitude of the mid-Winter Sun illumines the Fintry Hills to the east of my home in unique ways. Hunting Buzzards are quite common sights this time of year. Often, I see them being harassed by crows which create fascinating aerial displays. The snow-capped summits reveal captivating details and when it thaws and melts, I’ve been mesmerized by the cascades of water tumbling back down into the valley. I’ve enjoyed watching Jacob’s sheep foraging on the land near my home, with their thick winter fleece contrasted against the blinding white of snow-covered fields. On other days, I’ve been lucky enough to glass small groups of Redwings wintering here. And while out for a saunter on the Castle drive, I’ve been lucky enough to watch battalions of Chaffinch, Bullfinch and even the odd Stonechat foraging in the leaflitter at the side of the road. I’ve also been delighted by watching the acrobatic displays of Red Squirrels negotiating the conifer trees around Culcreuch Castle Estate. They’re certainly making a comeback around these parts!

One of the great virtues of both the 8 x 30 and 10 x 35 is their instant optical gratification. Despite their smaller exit pupils, they never induce blackouts unlike many wide-angle roof prism binoculars I’ve tested. They also serve up uniquely immersive views, with their wonderful wide-angle optics, as well as the unmistakable impression of being embedded in the image. I’ve come to appreciate the 10 x 35 in recent weeks. Its stereoscopic qualities really stand out when viewing targets in the middle distance. I’ve been captivated by the River Endrick, watching the water undulate as it flows over rocks beneath it. Scanning the hills with the 10 x 35 is also immensely enjoyable, with tall conifer trees swaying in the foreground against the soaring crags in the background. You really get a much more heightened sense of spatial awareness while viewing through the 10x glass over the lower powered 8x instrument. I find I can hand hold the lightweight 10 x 35 more steadily than a typical 10 x 42 roof prism instrument. Maybe it’s the way my hands engage with the chassis or maybe it’s attributed to its greater proximity to my centre of gravity.  I don’t know exactly. But what I can tell you is that the 10 x 35 Nikon E affords a unique viewing experience possibly only matched by its newer incarnation – the venerable Nikon E II 10 x 35. You really have to look through it to fully appreciate its enchanting qualities!

The 10 x 35 also delivers its charms on the night sky in spades. There is nothing quite like it actually. The smaller exit pupil darkens the sky background allowing the refulgent beauty of the Winter stars to really stand out. I’ve been enjoying views of the Pleaides and the Hyades with this glass; the 10x magnification and wide, engaging field of view working together to create unforgettable viewing experiences, especially now when they transit the meridian before local midnight. The Sword Handle of Orion is also a favourite target with this instrument as it’s so comfortable to view just above the leafless trees to my south. And after it culminates, I’ve very much enjoyed observing brilliant Sirius – The Rainbow Star – not far from the southern horizon coruscating wildly in gorgeous pastels of red, green, blue, purple and white as the light differentially refracts as it passes through turbulent Winter air. That’s just one of the advantages of having the brightest star in the celestial realm so low down in my local skies. Finally, in the wee small hours of the morning, with no Moon in the sky, those wondrously dark winter skies here in rural central Scotland have shown me some of the most beautiful and compelling handheld views of Praesepe and the Beehive Cluster in Cancer with the 10 x 35. It’s almost as if this binocular were tailor made to contemplate such things!

Now that the Winter Solstice has finally arrived, daylight will get longer as the Sun begins its preordained sojourn north again. Roll on the Spring and the long days of Summer!

Post Scriptum: December 26 2022

I’d like to report the results of two more experiments.

It occurred to me that a small binocular like the E II 8 x 30 being stored in a water and airtight Tupperware container with desiccant at room temperature will allow efficient diffusion of gases. The container has 20 sachets each containing 10g of activated silica gel. That ought to create a strong concentration gradient for the net diffusion of a small molecule like water vapour (molecular weight 18 which is considerably smaller than the average molecular weight of air) out of the inside of the binocular. Such a long-term storage strategy ought to thoroughly dehydrate the air in the interior of the instrument. And if that were true, I reasoned, it wouldn’t matter if I treated the binocular like any waterproof, nitrogen-gas-filled roof prism instrument. It should not fog up internally under any conditions so long as I kept to this storage routine.

I can now disclose the result of two further experiments. At five to midnight on Christmas day, I ventured outside with the EII 8 x 30. Temperature +2C, 75% humidity. The sky was clear and I enjoyed 45 minutes of stargazing wearing only light gloves. But instead of returning the instrument to the Tupperware container at the same temperature as the ambient outside air, I just brought it straight inside the house(temperature +20C) like I do with my water and fogproof roofs. The chassis quickly became covered in water as the cold metal encountered the warm inside air. The outer lenses fogged up, as I expected, but after a few minutes, I could see that the interior of the binocular did not fog up. Once it was dried down and left to further air dry, the inside remained crystal clear; no internal fogging observed! I then returned the instrument to its Tupperware container.

In a further experiment conducted on Boxing Day, I ventured out for a two hour glassing session. Temperature +3, 85 per cent humidity. This time I did not wear gloves (I did miss them however as the magnesium alloy chassis really gets cold fast). Time 12:00-14:00. Once again, I brought the instrument straight into my living room(temperature +21C) and watched what happened: once again, the chassis rapidly became drenched with condensed water, and the outer lenses fogged up. But after some of the water evaporated away, I could see that the inside of the instrument was crystal clear, with no signs of fogging. Once all the water had dispersed from the outer lenses, the instrument showed no fogging internally!

Conclusion: Storing the Nikon E II 8x 30 in this desiccant laden Tupperware container prevents internal fogging. Because the air is dry inside the instrument it should not fog up in any realistic situation I will encounter. No need to acclimatise the Tupperware container either. I can use it in much the same way as a modern roof prism binocular.

Yeeeehaaaw!

De Fideli.