7x35 Aculons, Featherweights, and 7x35 Porros in General (1 Viewer)

[Red_Shoulder]

I really like my 7x50's from the JT-II and MIOJ period, but I have really warmed up to the 7x35's lately. They have a lot going for them:

1. Closer focus

2. Generous 5mm exit pupil

3. Smaller size

To name a few of the advantages. I recently purchased a pair of 7x35 Aculon. Would they make my older binoculars obsolete, with the new coatings? I had wondered. How good will sharpness be?

Also, I thought I would do a bit of a review, in case someone was interested in getting into birding, but didn't want to spend a lot of money. The 7x35's are good to start with, and if you feel the need to move up later, you'll have a pair for the spouse, kids, etc. Please keep reading for other considerations, though.

Granted, I use and like the older, larger 7x50's, but the 7x35's seem fairly small. I think these would be small enough for most people. While lightweight, the body and focuser seem to be metal, and that's most of the binocular. I was expecting more plastic, probably partly due to the rubber coating, and when I looked closer, had a happy surprise.

There are smaller binoculars available, but some have a much smaller exit pupil, requiring more precise eye placement, which is a bit of a hassle. Though not too bad, I suppose. The 7x35's are fairly compact, though, and I've found 5mm to be fine for eye placement.

The 7x35 Aculons are featherweights. Wide field, relatively compact 7x35's with good performance in the center that falls off at the edges. It is personal preference as far as preferring the purer view or the wider one. It was amazing how similar the profiles of the Nikons were to other, older, featherweights. Hopefully I'll get around to posting a photo.

The lack of flare/glare is impressive, and would probably beat some much more expensive binoculars. I was getting the sun in the field (very dangerous, don't do this!) trying to get a problem with flare! Got a bit on the edges, but not the center, maybe not even all the time. Impressive performance in this important test.

I still plan on using my older binoculars. The 7x50's have a purer field, as can narrower field 7x35, which is nice. Also the older binoculars seem sharper, with wider sharp field (I am not sure about wider sharp field, and need to test more. Weirdly, seems to vary on the Aculons? ) But the newer coatings on the Aculons give better color and contrast. Its probably personal taste as to whether the differences in coatings and sharpness are pronounced. I didn't want to stop using my oldies anyway, did I?

I'd be interested in a size and performance comparison between 7x35 and 8x42 Aculons, as they seem similar in many ways. The 12x50's weren't that far behind the Monarch and Terra, it seemed, although I just looked at the store, and may have looked at the center more than the edges. I wasn't convinced there'd be real differences in the field between these 3, they seemed close.

If you mail order, you may need to send them in immediately if they arrive out of collimation. Mine are ok, maybe having a bit of an issue (or is this normal at closer ramges?) But they seem lined up at distance. Hopefully, Nikon checks collimation on these.

I have read about a 25 year no fault warranty. Mine arrived with a lifetime warranty against defects. I would think most defects would become apparent in the first couple weeks, or immediately, so I don't get that excited about a lifetime warranty anymore.

But if I could send them in to get collimated for $20+the cost to ship 1 way, that would be very important. I don't think you can get these collimated, for less than they cost new, here in the USA.

Of course, with porros, you may be able to conditionally align them yourself, which is potentially a huge advantage. A big part of the reason I go with older ones. I'm generally not willing to tear in to new binoculars and void the warranty. I think it is important to consider collimation.

Really happy with the close focus ability of the 7x35 Aculon, they're down around 10 ft. The shorter focal length of the 35mm objectives vs 50mm helps here.

Also eye relief seems decent, and they have retractable eyecups.

These are good binoculars. If you are interested in birding, but don't want to spend a lot, or just want a backup, or pair for the kids, these are a good place to start.

 

[Binastro]

Red Shoulder,
All of the Aculons I consider to be good and excellent value for money. Occasionally they have been out of alignment, but Nikon seems to have stricter controls than some others.
The Action VIIs are very similar although the 10x40 is actually 11x40 and short eye relief.

The coatings on all these lower priced offerings usually have plenty of uncoated surfaces.

I consider the similar Pentax and Olympuses to be almost as good.

They are ideal for astronomy, where extra features needed by birdwatchers are unnecessary.

Although 9.3 deg or so for a 7x35 seems wide, my Minolta Standard at 11.05 deg is in a different class.
I really wish the old EWAs were made fully multicoated.

 

[Steve C]

Even with the modern coatings, the Aculon is pushed to the limit of its coatings by the sheer optical optical superiority of a really good old time porro like the Bushnell Rangemaster, or even the Bushnell Custom. However the Rangemaster's are HUGE, having 7x50 size prisms. They look therefore like a 7x50 sawed off at the objective end. The older Bausch & Lomb Zephyr is right in there with the Rangemaster optically and retains the compact nature of the 7x35 format. The 8x30 Zephyr is a treat.

I agree that they are brighter than most of the basic level JTII 7x35 binoculars, even though the oldies are still good enough to go birding with. The Aculon is a very nice glass for little money. Nikon will collimate, but with the customer having to pay shipping both ways, it is likely simpler to get another Aculon . that said, I agree the Aculon is a very nice starting point.

 

[OPTIC_NUT]

Just to clarify:

----coatings and general field quality (as in, in or out of focus across the field)
...are two very different things.

Basic 3-element eyepieces are the start.
They have great eye relief at 7x50, but that shrinks as the objective goes down
(because shorter fl's are used), or the power goes up.
Aculons have an aspherical field lens on a basic Kellner, so the field is larger,
but it can't keep focus all the way, and its eye relief at 7x35 is fairly low.
That's been true for various brands for 70 years or so.

Next step is 4 or 5 element eyepieces. You almost always get both more eye relief
and a flatter field that is sharper near the edges as well.
They cost more...just a bit. Nikon 7x35 Action Extremes, for example.

Something like the Zephyr is an advanced eyepiece design, precision field of limited size.
Such binoculars (in the Ultralight smaller family) are usually a 5-element stretched-Erfle type.

There are other featherweights that are a 3-element with an aspherical surface,
used for about 7 degrees of field. Excellent field, but still a relatively lower eye relief.


Something like the Rangemaster is a 5 or 6-element EP with both a widefield design and
an aspherical surface.

Aculons are great for their class. Using them at all requires eyes you can put close
to the first glass, which also helps them do their job with the fiield. It's a great basic
design, but there are others that give you outer field quality and/or eye relief improvements.

 

[henry link]

O_N,

I have a few questions about some of the assertions in your last post. For clarity I’ve put your statements in quotes and my questions about them in all caps.

“Aculons have an aspherical field lens on a basic Kellner, so the field is larger…”

HOW DID YOU DETERMINE THE DESIGN AND NUMBER OF ELEMENTS IN THE ACULON EYEPIECE?

“Something like the Zephyr is an advanced eyepiece design, precision field of limited size.
Such binoculars (in the Ultralight smaller family) are usually a 5-
element stretched-Erfle type.”

WHAT “ADVANCED” DESIGN DID THE 7x35 ZEPHYR USE AND HOW DID YOU DETERMINE IT?

WHAT IS A “PRECISION FIELD” AND A “STRETCHED-ERFLE TYPE”? I’VE NEVER SEEN THESE TERMS EXCEPT IN YOUR POSTS.

“There are other featherweights that are a 3-element with an aspherical surface,
used for about 7 degrees of field. Excellent field, but still a relatively lower eye relief.”

ONCE AGAIN, YOUR POSTS ARE THE ONLY PLACES I’VE FOUND ANY REFERENCE TO GLASS ASPHERICS BEING USED IN OLD JAPANESE CONSUMER BINOCULARS BEFORE THE DEVELOPMENT OF MOLDED PLASTIC LENSES. CAN YOU SUPPLY SOME CORROBORATING EVIDENCE FOR THAT?

“Something like the Rangemaster is a 5 or 6-element EP with both a widefield design and
an aspherical surface.”

WHY DO YOU THINK THE RANGEMASTER EYEPIECE USED AN ASPHERICAL SURFACE? I HAVE DISASSEMBLED A RANGEMASTER EYEPIECE AND FOUND WHAT LOOKED TO ME LIKE A CONVENTIONAL 5-ELEMENT ERFLE.

Henry

 

[Binastro]

Henry,
Sometimes optics were hand figured by the likes of Horace Dall in England. Not exactly aspheric but to give the best star images. He hand figured everything from a Merz 9 inch or 11 inch refractor to everything sent to him, often at no cost. He refigured his own made 95mm short focus refractor for me at no cost. I found his name on the objective cell. He said come back in a week. I gave him and his wife a present. He also made microscope objectives out of gemstones with high refractive index.
There was also a U.K. person who coated old Leica lenses and hand figured or aspherised a lot. Jason Adams maybe.
It may be that some Japanese technicians were also skilled at this.
Horace Dall single handedly kept Leitz and maybe Zeiss microscopes going throughout WW2.
Other English telescope makers routinely aspherised optics, so it would not surprise me to find some improved Japanese optics.

Some of the Dallmeyer 36inch f/6.3 lenses for F52 cameras were aspherised or hand figured to improve performance.
I think this is a lost art nowadays.

The Aculons have a wavy change of magnification as you move across the field.

 

[henry link]

Right Binastro, I know hand figuring telescope objective lenses was done in those days and still is for very high end optics. I think I recall reading that some German military binoculars used aspheric lenses as far back as WWII. I just haven't seen any evidence that aspheric elements were used in mass marketed consumer binoculars before the Nikon Diplomats of the early 1990s. Nikon wasn't shy about trumpeting the aspheric lenses in those binoculars as a great innovation. Of course, they used inexpensive plastic molded lenses as I'm sure the Aculons do now. I'm not saying earlier glass aspherics were technically impossible, just expensive. Their widespread use seems particularly unlikely in the inexpensive "featherweights" mentioned in O-N's post. I'd like to see some convincing independent evidence to back up O-N's suppositions.

BTW, I'll clear my PM mailbox.

Henry

 

[Red_Shoulder]

Although 9.3 deg or so for a 7x35 seems wide, my Minolta Standard at 11.05 deg is in a different class.
I really wish the old EWAs were made fully multicoated.

I wish we could multicoat old binoculars! Or buy the same design new! I'll have to keep an eye out for the Minoltas.

 

[Red_Shoulder]

Aculons are great for their class. Using them at all requires eyes you can put close
to the first glass, which also helps them do their job with the fiield. It's a great basic
design, but there are others that give you outer field quality and/or eye relief improvements.

They work fine with the rubber eyecups fully extended, so should work with glasses, at least fairly well.



These have enough eye relief, I'm not sure if you want to put your eyes as close as possible. The Skippers have eye relief, and if you put your eyes too close, it causes problems.

 

[Binastro]

They don't make new fully multicoated EWA binoculars.

 

[OPTIC_NUT]

Skippers (the 7x50s, right?) have good eye relief.
Aculon 7x50s are very generous, too....it comes with the 7x50 territory.

I thought I'd nip my habit in the bud with some Meoptas, for amazing multicoating, etc.
Most days here, though, the edge-glare off objects is harsh through them, though.
Bear in mind, my eyes are quite sensitive, so losing 20-30% is meaningless.
I love the detail of th better oldies. I think the subtle ambers of the 50s-70s
are actually a 2-layer chemically-set multicoat, but it's hard to find any details,
and really expensive to get a spectro-photometer for lenses. My eyes are happy, though.
Thorough cleaning really made the difference. It started with lighter fluid on the Kowa Prominars,
and then went to multi-solvent for the IFs and precision-fields. There are some local camera
restorers I got to watch.

Near as I can figure, the amazing Pentax Takumar SMC didn't make it from cameras to
binoculars in the 70s. Could make for some killer bino-scopes, though...two 400mm telephotos.

 

[OPTIC_NUT]

When I want close focus, I just tape another 50mm objective over and enjoy the monster
macro view from 1-2 ft. CLoser than 15 ft, the image-split is quite irritating,
just the same as super-bad collimation, so mono is better for me.
Papilios would fix that, of course..or a dissection microscope.
8x21 close-focus Selsi monocular for examining mummies, Aztec pottery, Pollacks, and cuneiform.

For watching giant ants, it's the Steinheil TeleQuinar spotter conversion at 10ft.
Looks just like the nature shows, at 25x.

 

[Red_Shoulder]

Yeah I've noticed that the Aculons are brighter in the day. It doesn't seem to be much afvantage, though, i like my old ones. I think the old 7x50's are still going to be brighter at night. That a lot of gain in aperture, although if your pupil's don't open up to the full 7.1mm you'd lose some. Might be better off with 10x 50's then.

Binastro that's true, but these are close. I wish we could get multicoated old binoculars. An 11° binocular sounds a lot wider, but these seem similar width to some wide Sans and streiffe that I would call featherweights, that are marked as quite wide.

I played with them today, though, and, kind of like you said O_N, you need to have your eyes fairly close for the full wide field. I think I used the eyecups somewhat extended, though, this weekend and got nice views. Fully extended eyecups cuts off some of the field. But still probably a decent view.

I hadn't thought of that! SMC in old binoculars! I wish.....

 

[Red_Shoulder]

Henry,
Sometimes optics were hand figured by the likes of Horace Dall in England. Not exactly aspheric but to give the best star images. He hand figured everything from a Merz 9 inch or 11 inch refractor to everything sent to him, often at no cost. He refigured his own made 95mm short focus refractor for me at no cost. I found his name on the objective cell. He said come back in a week. I gave him and his wife a present. He also made microscope objectives out of gemstones with high refractive index.
There was also a U.K. person who coated old Leica lenses and hand figured or aspherised a lot. Jason Adams maybe.
It may be that some Japanese technicians were also skilled at this.
Horace Dall single handedly kept Leitz and maybe Zeiss microscopes going throughout WW2.
Other English telescope makers routinely aspherised optics, so it would not surprise me to find some improved Japanese optics.

Some of the Dallmeyer 36inch f/6.3 lenses for F52 cameras were aspherised or hand figured to improve performance.
I think this is a lost art nowadays.

The Aculons have a wavy change of magnification as you move across the field.

Binastro, I've heard of people getting older telescopes refigured, and people grind their own telescope mirrors. Very interesting post! I thought you might have to re-do the lens, although I have an older that was coated during the war, from what I was told.

Any idea what gemstones were used? Wow

 

[Red_Shoulder]

When I want close focus, I just tape another 50mm objective over and enjoy the monster
macro view from 1-2 ft. CLoser than 15 ft, the image-split is quite irritating,
just the same as super-bad collimation, so mono is better for me.
Papilios would fix that, of course..or a dissection microscope.
8x21 close-focus Selsi monocular for examining mummies, Aztec pottery, Pollacks, and cuneiform.

For watching giant ants, it's the Steinheil TeleQuinar spotter conversion at 10ft.
Looks just like the nature shows, at 25x.

I've been using a single 50mm focal length double convex for up close. On its own, not bad. I have 42mm achromats handy, I bet they might work on front, might have to try it, especially on velvet ants.

 

[Red_Shoulder]

Even with the modern coatings, the Aculon is pushed to the limit of its coatings by the sheer optical optical superiority of a really good old time porro like the Bushnell Rangemaster, or even the Bushnell Custom. However the Rangemaster's are HUGE, having 7x50 size prisms. They look therefore like a 7x50 sawed off at the objective end. The older Bausch & Lomb Zephyr is right in there with the Rangemaster optically and retains the compact nature of the 7x35 format. The 8x30 Zephyr is a treat.

I agree that they are brighter than most of the basic level JTII 7x35 binoculars, even though the oldies are still good enough to go birding with. The Aculon is a very nice glass for little money. Nikon will collimate, but with the customer having to pay shipping both ways, it is likely simpler to get another Aculon . that said, I agree the Aculon is a very nice starting point.

The oldies can be great, definitely wanting to get Zephyr and custom, wasn't familiar with Rangemaster.

 

[henry link]

I hadn't thought of that! SMC in old binoculars! I wish.....

Well, they do exist, but are probably quite rare finds in the US now since Pentax was not a big player in the binocular market here. See post #40 in this thread from Cloudy Nights:

http://www.cloudynights.com/topic/521918-why-no-8x40-extra-wides/page-2#entry6965586

Just be careful to avoid the old Pentax binoculars with the notorious gold metallic coatings.

By the mid to late 1980s there were plenty of partly or fully multicoated Porros from various Japanese sources. The last Bausch & Lomb Porro Discoverers (7x35, 7x50, 9x35, 10x50) were examples of old B&L designs which were kept in production in Japan long enough to benefit from multicoating. There probably aren't many of those around either, since they were relatively expensive Porros at a time when roofs had already become the fashion in high end binoculars.

 

[Binastro]

I recall rubies, but not sure if they come in less red versions. Amethysts exist almost colourless.
H.Dall had world records with his gemstone microscope objectives, as well as many other, such as barometers, bibles per square inch etc. Pocket 6 inch aperture folding telescopes. Quite a lot of his items are now in the Science Museum, Kensington.

Careful with Pentax old lenses as many used thorium glass and are now brown or yellow. I wouldn't use these next to the eye. Particularly shorter focal lengths. Same with old Canon, Olympus etc.

Minolta used Achromatic 2 layer coatings early on with their lenses.
The 12x50 Activa has very high transmission I think, but not very wide.

I doubt that Aculons transmit more than 70%. I want 90%, which means prisms also multicoated.

Pentax gold coated binoculars are awful, I don't know who thought of that.

 

[Binastro]

Not sure what jewel, but world record n.a. 1.92 at the time.

Equivalent 280 bibles per square inch.

Spherometer accurate to 1/40 wavelength visible light.

Other world records also.

 

[Red_Shoulder]

Wow, I'll have to keep an eye out for SMC Pentax, their wide field binoculars seem interesting, too, though a search yesterday didn't turn up much. Pentax seems much less common on the used market.

I would like to try some of the gold coated, I've heard theyre bad though, for color cast. I like pentax stuff, though.

Hopefully I can find some of the Bausch & Lomb, too.

Very interesting info on H. Dall, was the advantage of the gemstone a higher refractive index, or was this just for fun?

Did binoculars have thorium glass, or are you referring to camera lenses? I would like to get a Geiger counter to test this, got a CD-V 700 (lower, more sensitive range) but I think it just picks up most gamma and some beta, no alpha. It broke, anyway. I doubt 400mm lenses have thorium glass, but really don't know. It was common in 50mm and faster 35mm lenses, I think.

This website claims 75+% for old CZJ 7x50's, which I think sounds about right. Assuming the older bins have 75%, the Aculons are brighter, so I'd guess closer to 90%.

http://www.allbinos.com/233-binoculars_review-Carl_Zeiss_Jena_Binoctem_7x50.html

Is that actually real gold in the coatings?