Long distance focus issue with legend hd 10x (1 Viewer)

I'm having an issue that I need to resolve rather quickly if possible. I have a pair of bushnell legend ultra hd 10x42. Other than the following issue I think they are amazing for the price. Couldn't be happier with pretty much everything, except...

I've always had a hard time getting the focus perfect on certain objects. Most of the time I can fairly quickly focus on a drop of water on a plant, or on a nearby bird, or perhaps a distant building or tower or something, but other things are more difficult. For instance, I was at the store the other day to compare my pair with another to see if it was an issue. They only had an 8x32 legend in stock.

I looked at nearby cars and signs and flowers and both pairs were very sharp. The 8x32 seemed easier to focus quickly, but both fairly similar sharpness (more specifically, the ability to make them sharp). However, when I focused on far of forest way off behind the buildings that were two big parking lots away, I could easily focus the 8x30 legends, but I don't think I could ever get the 10x42 ultras to be perfectly in focus.

So my question is, do my binoculars have a problem? I know a decent amount about binoculars, and that the depth of field is less at higher magnifications, however it should increase with the distance of the object you're looking at. So I would think a flat field of tree should be easy to focus?

I have the one-year bushnell gaurantee where htey buy them back for any reason. So, I want to get this figured out before july when it's no longer valid. Unfortunately, I don't have ANY similar binoculars in size or quality anywhere near me. I recently bought a pentax dcf cs 10x42 online hoping ot replace the bushnells with a sharper set. They were in fact sharper and easier to focus, but inferior optical quality otherwise (much more CA and a tad more washed out contrast).

This leads me to think my pair might be bad, but I don't notice any collimation issues causing eye strain or noticeable object shifting. And it seems odd that they work at certain distances/objects but not others. The fact that I've used other binoculars with no issues leads me to believe it isn't my eyesight, which passed an exam with no issues within the last year or so. Any help would be greatly appreciated.

I'd send them to be repaired, but I'd rather not spend $20 to ship them there and back (how lame is that?) And they could just as easily be damaged in shipping and come back worse. Ugh.

And for the record, I bought these as hiking/astronomy binoculars. Since I got them the weather here has been horrible. Literally for almost a year! So I didn't start using them more often until recently hiking and animal watching. Hence the long wait...

I have the 10x42's and don't experience the problems you are describing. The most logical thing to check would be the diopter setting. Make sure it is set correctly for your eyes at the longer distance, and locked down, and then recheck again at the closer distances. Other than a diopter problem or a possible inadvertant fingerprint on one of the front objectives, its a mystery to me.

lilcrazy2 said:

I have the 10x42's and don't experience the problems you are describing. The most logical thing to check would be the diopter setting. Make sure it is set correctly for your eyes at the longer distance, and locked down, and then recheck again at the closer distances. Other than a diopter problem or a possible inadvertant fingerprint on one of the front objectives, its a mystery to me.

Click to expand...

I've adjusted the diopter setting extensively, and it always ends up right back in the middle, which would make sense if my eyes are good and the setting is glass calibrated. And most things are fine. I'm actually extremely impressed with macro plant life and bugs and such...

I have a nikon lens cleaning pen, which seems to work great. I try not to over clean the lenses, and I never touch them if I can help it. I've never seen anything on them when I inspect them. They look perfectly clean. :-/

I was under the impression that the diopter is set once and never touched again. Is this not the case? I'll play with it more today to see if anything is different.

I did some further testing today now that I knew it was a distance focus issue. I think I found the problem, but not sure what to do about it.

The issue is that the focus knob is ULTRA sensitive. On top of that, changing directions can cause a bit of a squishy-ness when you start turning the knob in the new direction. I've tried many other binoculars, and this seems to happen mostly with waterproof binoculars over standard. Perhaps it's the seal and lubrication? Anyway...

I tried a dakota 10x42 roof prism, nikon 10x50 action porro and the 12x50 action ex porro all side by side with mine. I found every pair easier to get into a sharp pinpoint focus than mine at a distance. I did find however that I can in fact get mine to focus clearly now, but the effort is excruciating. I have to very very slowly and gently turn the knob until it is perfectly in focus. Sometimes it passes a bit too far from perfect focus and I then have to go a quarter turn the opposite direct and start again, since very small changes in direction aren't perfectly smooth.

So apparently it is simply the focus wheel. Is this normal? Do I simply not like the looser feeling focus knob precision? Or is this abnormal? It's not a drastic difference in movement than the other binoculars, but enough that pinpoint sharpness requires much more effort to achieve at long distances.

Is there any tightening adjustments I can make? Or should I send in my pair for repair? Or perhaps switch to another pair all together that had a different focus mechanism? I was amazed to see that these surpassed all the porro prism binoculars in quality. They truly seem like an excellent value if the focus problem I'm having can be solved...

First I have to ask how often you need to focus at long distances while birding? Most birding is done within 40m with a 10x binocular due to the relatively small size of the subject.

Since most 10x42mm binos will have a hyperfocal distance ~90m, objects from 45m to infinity should appear relatively sharp when the binocular is focused at ~90m. In theory as well as practice, there is no need to tweak focus at targets beyond the hyperfocal distance.

If you feel the focus is squishy first try cycling the focus knob from nearest to furthest several times to ensure lubricants are evenly distributed. If the knob feels loose on its spindle you may need to tighten the retaining screw(s). Best focusing technique is to pass thru focus and then back into it to minimize any mechanical slop/backlash.

That said, I think the Legend Ultra-HD has what is considered a "fast" focus. That should be a good thing for birders but some folks just can't accomodate it. You might want to have someone else try your bins and see what they think. Even with "perfect" vision, focus accomodation deteriorates with age.

Finally, at long distances the atmosphere will always affect the focus, more so as we move into Summer.

I'm not familiar with the model, but if you're finding it "excruciating" to get them into focus them at any distance (up to and including stars at ~infinity) - which should be more or less effortless - they're obviously unworkable.

It seems to me you need to contact the manufacturer to see if they can be examined and either repaired/replaced under warranty or at reasonable cost; if not perhaps you're better off going with another model which you've tried and you know works for you.

RJM said:

First I have to ask how often you need to focus at long distances while birding? Most birding is done within 40m with a 10x binocular due to the relatively small size of the subject.
...
Finally, at long distances the atmosphere will always affect the focus, more so as we move into Summer.

Click to expand...

Well I have been looking at birds, but I also use them for hiking and stargazing. They are an all around binocular for me. The hiking is where they are falling short with focus troubles. Although the birding focus speed is still less than optimal in my opinion it does word fairly well with sharp results. I've used other binoculars that are half as challenging to focus, but none are of the optic quality of the bushnells so far.

I know this isn't an atmospheric problem, because as I said in the original post, I tested other brands with the same mag/aperture side by side and had no issues, even though the other glasses was lower quality. So perhaps these are just too "fast" focus for me? I just wanted to be sure it isn't "my pair".

I don't want to have the fixed by bushnell, because they want me to send them for $10 and include $10 for return shipping. I don't even have enough evidence that something is wrong. It could be the way the focus works normally. I don't know. And with my luck they'd come back worse from shipping or exactly the same for $20 out of my pocket. The simple fact that I need to pay for BOTH shipping directions makes me want to go with another brand. Why should I have to front the cost if it truly is their defective product?

So I think I'm going to return them and go with some eagle optics ranger ed 10x42s. They seem roughly similar although possibly with better optics/design. I've read here that the standard ranger focus is more what I'm looking for:
http://www.bestbinocularsreviews.com/Eagle Optics8x42Ranger-80.htm
Does anyone happen to know if that ed pair is the same?

Anyhow, thanks for all the help. Hopefully these will fill my needs.