Modern Opticron binos meet Vintage Russians..

[F15Rules]

Last year I bought new a lovely pair of Opticron SR-GA 8.5x50s, made in Japan. Like all Opticron products I have ever used, they are very well built, deliver full aperture (no stopped down lenses here), and have superbly sharp optics. The only improvement I would ask for if I could would be a slightly wider field of view (the Opticrons have a 5.2 degree field).

A couple of years back I sold a pair of 1980s Tento BNU 7x50s to a member here on SGL and have since regretted selling them (how often have we said that, in hindsight??)

Fortunately, the older USSR produced bins do come up for sale on a regular basis on eBay, and a while back I resolved to look out for another pair.

Although used Russian bins are almost ten a penny (it seems most house clearance firms find them in lofts etc on a regular basis!), you do have to try to box clever and fine a pair that has been looked after and is in good collimation..well, last week I found a pair that intrigued me, in that they were old (made in July 1976), and sounded as though they were genuinely in great condition.

I asked a few questions of the seller (I find that doing so can tell you a lot about both the seller and the item for sale,both directly and indirectly), and as I had hoped, this pair of Tentos had been bought new by the seller in 1978, from Dixon's photographic, for £18.. bear in mind that in 1978, as a young man of 22, I was taking home less than £22 a week, so these were NOT a cheap item, however much they might have been subsidised by the USSR to pull in much needed foreign currency.

The seller had bought them to watch birds in his London garden, used them a few times, lost interest, and packed them away until an imminent recent house move brought them back to his attention.

So I took the plunge and we agreed on a price of £55 including shipping - a bit above the common eBay price range of £30-£50, but I thought the condition and provenance of these made them worth a little more.

The bins arrived two days ago and are in wonderful condition for an almost 45 year old binocular. The coatings look great on both objectives and eyepieces, although I would think they may well be just single coated Mfg, due to their age. Two pairs of snug fitting filters were included, (yellow-orange and green), along with a good leather case and strap, eyepiece and objective covers...and that (thankfully) faint but unmistakable whiff of dead halibut, common to most Russian bins🙃😁..

Anyway, I plan to do some serious comparisons between the Tentos and the Opticrons this season, and will post up my findings at a later date. But on a short first look the night the Tentos arrived, using both pairs solely on M45 (Pleiades), seated in a recliner and handheld my initial impressions are:

Opticrons:

Fabulous contrast, really black sky background, very sharp on axis and out to about 85% of the 5.2degree field, pure white brighter stars. The higher magnification and smaller field made the main cluster very dominant in the view.

Tento:

Noticeably wider field of view (c7degrees), nice contrast, but definitely a brighter background, very sharp out to c 65-70% of the field, with the faint stars of the background really framing the view of the Pleiades nicely.

The overall impression was that the Opticrons delivered a darker sky with more of a "diamonds on velvet" appearance, whilst the Tentos gave a more "panoramic" vista. I liked both views immensely.

Interestingly, although the Tentos definitely seemed to deliver a bit less bright images than the Opticrons, I felt I could see pretty much everything through the Tentos that I could with the Opticrons. For example the fainter trailing arm line of faint stars to the south of the main cluster body was visible with both instruments, albeit perhaps slightly more faint in the Tentos. In this regard I think the bigger 7mm exit pupil , my ageing eyes, and older coatings of the Tentos versus the 5.9mm e.p. and modern multi coatings of the Opticrons were the key influencing factors.

Overall, I am very impressed with both sets of bins and look forward to more comparisons on the winter sky☺👍.

 

Here are some pics of the two together. Thanks for reading.      Dave

Edited October 30, 2019 by F15Rules
Photos added

[Saganite]

Look forward to your review Dave. I still have those  Tento 7 x 50's, superb binoculars and keepers for sure.

[NGC 1502]

Hi Dave.   I’ve read your post with interest because last year at a bring & buy sale at my local club I bought a pair of the Tento 7x50s from a clubmate at a bargain low price 👍.  They are in top condition, with no faults apart from a tiny bit of slack in the central focusing, this could be fixable as a DIY job but I’m reluctant to meddle as the bins work so well.

I’ve compared them several times with my Jenoptem 10x50s. The Jenoptems give a more contrasty view, perhaps because of the 5mm exit pupil compared with the Tento’s 7mm.  The Jenoptems are super sharp in the central 60-70% but outside of that get mushy, perhaps the design was pushed too wide ?  But now in my 70s I’m finding that I can hand hold 7x a lot steadier than 10x.    The Tento’s hold sharpness better towards the edge of field and this plus the noticeably  steadier view means I use them more.  Of course many would say that for older users a 7mm exit pupil may be wasted, I do understand that, but I like the view so that’s what counts.

And thanks for reading my post, I’m looking forward to reading your findings when you can......

I always hesitate to use “pair” when talking about a “bi” nocular but “pair” is so widely used I usually comply 😀

Cheers from Ed.

[Merlin]

I once tried a pair of 10X50 TENTO's and they were rubbish optically. Conversely, I had a pair of 20X60 TENTO's and they were good. Wish I'd kept them.

[F15Rules]

"And thanks for reading my post, I’m looking forward to reading your findings when you can......"

And thanks to you too, Ed☺. Your experience sounds very similar to mine. There is something about these 7x50s that is just very appealing. Mine have a very slight yellowish cast in daylight, but this is invisible at night, and what strikes me is just how sharp they are. 

2 hours ago, Merlin said:

I once tried a pair of 10X50 TENTO's and they were rubbish optically. Conversely, I had a pair of 20X60 TENTO's and they were good. Wish I'd kept them.

I think you were unlucky Merlin. I have owned around 10 different Russian binos and only ever had one with problems.. ironically, it was a 20x60 pair which were out of collimation, and the vendor readily gave me a full refund. Sometimes the focusing wheel can be a little loose, bit optically I have nearly always found them to be good.

Dave