Focus shift fault, common?

[Dave H]

I've had a few very cheap binoculars in my time. Seems I know that saying well, "Buy cheap; buy twice".
I thought that I had got that behind me when I became willing to spend more on my bins. Not THAT much, you know, around the £100 mark. Very much still in the budget class.

I have just received by post, what should have been a nice pair of Porros for my wife. She wanted something light, not much more than her 8x25 pair in use at the moment. These Helios bins seemed to fit the bill at 8x32 and 365g.

On checking them over, these bins have an odd focus problem that I have seen before and associate with very cheaply made bins. After focussing on an object at say 6m, making adjustment as necessary for the right eyepiece, if now they are re-focussed at around 3m (butterfly viewing distance) the right eyepiece needs to be adjusted again, and so on when back to 6m.....
They were also almost twice the advertised weight at 620g too. She may as well get full sized roofs.
I've sent them back, finding it awkward to describe the fault.

Is this a common fault/feature of bins?

PS, I did once consider the possibility that it was my eyes at fault, until I tried several bins which worked perfectly over any distance from closest to furthest.

[Dave H]

Caught again.

Recently, I bought a pair of Helios Patrol 8x32 bins. The full price of these would only be around £70. I bought them used "as new" for a lot less on Ebay.

They too have this fundamental fault where the focus difference (adjustment of the right eyepiece) at infinity is significantly different than that at a closer distance.

So, just lately two out of two budget Helios bins have had this fault. There's a pattern here.

[Callander1]

That just shouldn't happen, as long as you completely relaxed your eyes, then focussed. I still swear by the 10x50s I got in Aldi for £19.95. An absolutely brilliant bargain, and no problems what-so-ever.

[Dave H]

Yes, I agree. It's hard to imagine how this can happen after they have been manufactured, as some sort of failure. Shows a poor quality control at least.

I have two pairs of Barska bins. They too are budget bins. These are my "to go" bins, 8x32 when I want to carry a pair whilst fell walking and a 8x42 pair for birding/walk in the park. They are very good and are mechanically excellent. If it weren't for the slightly warm image colour I would not be considering other bins.

Dave