Diamondback 8x28 oddities (1 Viewer)

...diverted from http://www.birdforum.net/showthread.php?t=311261

ceasar said:

mfunnell said:

Just a quick update: the Diamondback 8x28s arrived this morning, and I am not disappointed.

They're the right size and weight for my purposes, fitting perfectly in the camera bag they'll live in without weighing it down. They give a good clear view. They focus 'the other way' from my Terras, but that's no big deal. I'll seldom use the two one after the other, and I can adjust quickly to either. Eye position is more critical with the Diamondbacks (not unexpected) and took me a while to sort out.

There are two oddities: the right eyecup sits slightly higher than the left in all positions, and I have to adjust the diopter way to the '+' side, unlike all my other binoculars where I centre it (with or without glasses). Related? I've no idea, nor do I know if this is a defect. But not a problem for me as everything is within the available range of adjustment. For about US$100 (including discount and $25 gift card that I will use) I'm not complaining.

I'll call this a successful exercise all around. Thanks again.

...Mike

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Re the diopter on the 8x28 Diamondback. Check it out very thoroughly.

See the 4th review in the link below: The binocular had to be returned because the diopter went haywire.

http://www.eagleoptics.com/binoculars/vortex/vortex-diamondback-8x28-binocular

Bob

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That's good advice - which I've taken. I've worked the mechanism, and it seems OK. If it is mis-assembly of some sort (and I'm inclined to think it might be) then it seems solid mis-assembly. (Does that make it better or worse?). I've worked the diopter adjustment back and forth between full ± adjustments multiple times, then returned it to where suits my eyes, and it has not varied (beyond the marginal tweaking made necessary by my rough-and-ready methods).

Sat on a level bench, with maximum extension of both eyecups and measuring with a ruler, the left is a tad under 122mm high, while the right is a tad+ over 122mm, about 0.5mm difference (roughly; using the usual conversion from tads to SI units). This may or may not be a symptom associated with the need for somewhat radical diopter adjustment but, again, I'm inclined to think it could be.

I've attached a photo (apologies for the quick P&S snapshot) showing how far from centre I have to wind the diopter adjustment. Note that my other binoculars (Nikon Action Naturalist III, Celestron Oceana, Zeiss Terra ED) have this set to zero to work with my eyes, with or without glasses.

Since it's consistent, and solid-feeling, and within the usable range of adjustment for my eyesight, I'm going to live with it given the price of the unit and the cost and inconvenience of international returns. This might not be acceptable to others, especially those who need negative diopter adjustment (where there seems to be little range available).

...Mike

If it doesn't change to any great extent you should be OK. Most people will have occasional minor changes in their diopter adjustments. Are you far sighted by any chance?

Bob

ceasar said:

If it doesn't change to any great extent you should be OK. Most people will have occasional minor changes in their diopter adjustments. Are you far sighted by any chance?

Bob

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No, rather nearsighted, as it happens!

...Mike

Just to update this thread - I've received a second set of 8x28 Diamondbacks and they do not have anything unusual about their diopter adjustment. If I set it to neutral (as I do for all my other binoculars) then they work just fine. The first set, with the wonky diopter, are going to end up in the glove box of my car. It will be an interesting experiment to see how they cope with a long, hot, Australian summer. If they don't cope, well, they're not expensive and Vortex has an excellent warranty.

...Mike