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Popular binoculars on Amazon: 30x60, Ruby Lens etc


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Until recently Amazon allowed sellers to give free or discounted stuff in exchange for reviews, which led to some pretty bad reviewing (if you don't do 4-5 stars you won't get more free stuff), which really shows on sophisticated products like binoculars. There are binoculars listed as "30x60", at the same time can fit in your palm (60mm objectives? magic!), and they are even night vision for £4.84!! Naturally, I bought them to review them. They are really 8x21 as you could already imagine from the pics, but the worst thing about them is that "red membrane" (in other clone listings it is listed as "ruby lens"), instead of being an ANTI-reflection coating, it is like the reflective sunglasses and reflects most of red and yellow light! You get a dark blue image! Then I signed up on the aforementioned review club so that I can get a discount on one of the best seller binoculars, a "SkyGenius 10x50" at £34. At that price you can get decent binoculars, but this 5-star reviewed best seller can't give a crisp image (frustrating, you try to approach the focus point and always pass without reaching it), can't even meet its own specs - I calculated the power at about 7.5x and the effective aperture is 43mm, with a noticeably undersized prism. I added a review to warn people that it is not a "fantastic value" as the serial reviewers claim, but strangely (or suspiciously) it was down-voted out of the front page (well, if you have an Amazon.co.uk account, why not upvote this review or the other 1-2 sane ones so that they appear above the paid for reviews and help some people). At least its small prisms were collimated and there was no ruby coating... I didn't stop there, I got another popular model at £12 (marked "hobby store uk 10x50"), which was the worst of the bunch. Red reflective "coatings", plus about 7x actual magnification, plus not more than 45 degrees apparent FOV and, the tour de force, just 19mm effective aperture... on a physically 10x50 binocular! You are lugging along a huge 800g 7x19 binocular that only shows blues and greens...

Attaching a photo of the binoculars, as well as a comparison of the images VS a set of affordable 10x42 roof prisms (£32 new from Astroboot - so cheaper than at least one set compared), the brightness is the comparative and so are the colors (kept same exposure/iso/white balance and raw conversion). It is a shame people buying their first set of binoculars will end up with such garbage, but there's very few legitimate reviewers it seems... 



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This has been going on for a very long time, which is one of the reasons the "ruby coatings" issue is the second on my list of reasons to reject here.

I also mention the weird 30*60 issue here, along with the common feature of internally stopping the aperture. I must admit, though, that I've never come across one as bad as the 50mm stopped to 19mm that you mention, but I do have a ruby-coated "70mm" (stopped to about 45mm) zoom BSO* that I haul out to demonstrate what to avoid when I give talks on the subject.

As far as consumer reviews go, I never trust the glowing positive ones - most are from people who are not qualified to comment on (say) optical quality - which is how these purveyors of trash get away with it: your average consumer will be less critical than any half-competent QC bod, so it's cheaper to do away with the latter and just refund any customer who complains.

* Binocular-Shaped Object

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Ahahaha. I spent a few seconds trying to recall the BSO brand before reading the note...

Great site, that was actually where I first read how to measure the effective aperture! I am used to seeing an obvious baffle in refractors (or usually in cheap finders), but binoculars are more sneaky, the 19mm "10x50" doesn't look suspicious if you look through the objective.

The seller of the £34 set had asked me not to post a review (I did a 3 star, being rather magnanimous I think - they still would be usable if they were less than half the price, no ruby coatings etc), and actually just now sent me a message that they reported me to Amazon for "malicious slander" because they saw that I give bad reviews to all binocular sellers (I indeed try post a review as a warning to all "30x60 ruby power" sellers), so I must be in the binocular business!

PS. This is the LED test of the binoculars with the bullying sellers, I added it to the review so it should show up there too.


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I put my comparative reviews into a blog post. An interesting comparison crop from the image I posted above (with brightness normalized, so only CA, colors sharpness is compared) is here:


The Innova is normally 100% sharp, but I can't seem to capture this in an image, anyone has managed to get perfect sharpness with binoculars and a DSLR? Any tips? I am using a DSLR with a Tamron 28mm prime lens, my first attempts with my 17-85 and 18-55 canon lenses were worse.

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