My Thoughts on the Asahi Pentax 8 x 40: Back to the Future? (2 Viewers)

[Dipperdapper]

Evening All,

Please find a link to my thoughts on the classic Asahi Pentax 8 x 40:

My Thoughts on the Asahi Pentax 8 x 40 Wide Angle(9.5 Degree) Binocular. | Neil English.net

It certainly raised some questions in my mind about the future of binoculars.

I hope you enjoy it!

Kind regards,

Neil.

 

[Canip]

Quote from your linked article:

„Resurrecting these classic Porro prism designs with enormous fields could be done at much lower costs than those commanded by today’s top wide-angle roofs. Can you imagine what could be achieved by applying state-of -the-art multilayer coatings to the optical surfaces of such designs? Adding a field flattening lens would also make them very sharp nearly to the edge. Re-designing the eyepieces with greater eye relief wouldn’t go amiss either. Adding seals would render them water proof and purging them with dry nitrogen gas would keep them from fogging up in cold /humid weather.“

If only the optics markets were that easy and simple ……

But as you say, we can only dream 😉

 

[Binastro]

The Pentax gold coated eyepieces are well known, and were a mistake that Pentax changed rather quickly.

I have several and don't like the coloured view at all.

There is a Soviet 8x30 binocular with a 13 degree field.

The very wide angle Porros seem common in the U.S. but less so here.

The Minolta Standard MK 8x40 has a 9.5 degree field, the 7x35 11.05 degrees measured.
The 10x50 7.8 degrees, although only 7.65 degrees if one doesn't get close to the eyepieces.
I used the 10x50 as my only binocular for ten years, besides the 20x60 and 20x80.

There was an EWA Zeiss binocular a long time ago.

The Koehler submarine periscope eyepiece was 120 degree AFOV.

The Ascot/ Bresser 7x32 has a 13 degree field. Also made in 8x40 over 11 degrees and 10x50.
But awful distortions from the mirror/prisms.

I have long complained of the miserably small fields of modern binoculars and, for me, excessive eye relief.

I have many good 10x50s with 7.5 to 7.9 degree fields, which all well made and give good images.

The 6x24 Amplivid and Komz 6x24 both have 12.2 degree fields.
I prefer the Amplivid as it goes in my pocket, but the image is rather dim because of the old mirror prisms.

For astronomy I prefer 82 to 92 degree eyepieces and don't like 100 degree eyepieces.

I prefer using the Swift 8.5x44 HR/5 to the 8x30 EII, even though the latter is better and doesn't have the flare problems of the HR/5.

Also the Komz 12x45 easily outresolves the 10x35 EII hand held.
Again the 10x35 EII is very nice but I prefer the Komz.

The Karlstein (Steiner) 6x25 micro binocular with 11.5 degrees is nice but a bit fat for the pocket.

I agree that multicoating old EWA binoculars would produce better results.

Regards,
B.

P.S.
A good example of the VisionKing 5x25 with 15 or 15.8 degree field is nice.

The Kronos 6x30 has a 12.5 degree field, with 7x35, 8x40 and 10x50 versions.
Mine are mechanically shoddy, but some seem to be better.

 

[Dipperdapper]

Cheers gents.

Brian, you're a mine of information as usual.

Those old ultrawide angle Porros do indeed seem to be much more abundant in the USA. I'm on the lookout for one of those super-wide 7x 35s models

It seems to me that the market is now being driven by ever-increasing field sizes. I note that field flattening(FF) technology is now being offered in sub £400 binoculars e.g. the Celestron Regal ED/ Meade Masterclass instruments with 8 degree fields. Although the Regal I tested was a bit on the heavy side for a 8x 42, the Nikon Monarch HGs are not and also possess FFs.

I'm sure that if a some clever engineers knocked their heads together they could create a terrific mid-size instrument with significantly bigger fields than those offered by contemporary models at an attractive price..........just musing out load.

Regards,

Neil.

 

[Canip]

If some clever engineers knocked their heads together they could create a terrific mid-size instrument …

Would I buy it? Likely.
Would you buy it? I guess so.
But would such an instrument be a huge success in the market? I doubt it if I follow discussions such as in this thread:

FOV - beyond what value is too much?

It seems, wider the Field Of View the better. One really can take advantage of very wide FOV? or, in other words One must go for the widest FOV available?

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