Sometimes they are referred to as doublers or boosters, but Opticron call theirs a Universal Tele-Adapter (UTA). It’s simply a small, low powered, fixed focus telescope that fits over the eyepiece of a binocular or spotting scope to increase magnification. A small, light, affordable accessory that, in my opinion, deserves a place in anyone’s pocket or bag.
I’ve spent quite a few hours over the last couple of weeks trying to figure out exactly what the UTA can and cannot do and filled up half a dozen pages of my note book with calculations and tables of figures. You’ll be relieved to hear that I’ve decided to leave most of those where they are, and concentrate of the key points.
http://www.opticron.co.uk/Pages/uta_2x.htm
The UTA comes with just a single lens cap and a wrist strap. I’ve been using a small draw-sting bag that came with some sunglasses for a bit of protection when out and about. Without the connecting ring the UTA is 88mm long 33mm wide and weighs 148g on my kitchen scale. The ring adds about 23mm in length and a bit more to the width. It’s perhaps a little bigger than I expected but still a good size for a jacket pocket or the corner of a bag. The eye relief is approximately 20mm but the eye lens is recessed another 12mm which seems a curious design choice. The eyecup extends 10mm in three stages, but the mid point indents are a bit soft and liable to collapse.
Opticron have of 8 connector rings to fit their range of binoculars and eyepieces. They sent me the one for my Opticron Classic 7x36 and another 3 in the hope that they would work with the other binoculars I own. With a little bit of diy I got satisfactory fits for all my full size models, but learned you really shouldn’t twist them on with glued on eyecups!
Opticron's previous UTA was 2.5x which I thought too high, making the view a bit dim and soft for my taste. Balancing up instrument resolution, the exit pupil diameter and the eyesight of the user is tricky and even a 2x I feel would be pusing practical limits. I estimated that the UTA’s magnification is actually 1.8x which I think is just about perfect for an 8x42 or 10x56, but even for this level of boosting, light levels need to be somewhat higher to get satisfactory results for a 10x42 for example.
In decent light and mounted on a tripod, I could see 1.8x smallet detail using the UTA than the binocular alone. However the extra boost can take the view close to the resolution limit of even better binoculars and will exceed that of some. As a consequence I could spot differences in contrast at the limit of detail with different models as a result, but I think most will find it entirely satisfactory with most binoculars in the field. I should stress it’s binocular resolution that is limiting, not the UTA.
When used alone, the UTA has about a 35° AFOV but with my 7x36 and 8x42 it’s a pretty modest 27° which is less than half that you might expect from binoculars alone or a decent scope. At least with my flat field binoculars the view is sharp edge to edge. On a positive note, the boosting actually appears to improve close focus a little.
Although I found I could get a very useful increase in the level of detail when used hand held, I feel you really need additional support to get the full benefit of the extra magnification. Bracing againt a post or a rail will make quite a difference. No doubt, a sturdy tripod is the best solution, but for me, a lightweight monopod is the more natural partner for those who prefer to travel light. Quite how much benefit you’ll get will vary with user and the binocular but for my 8x42 for example, the practical benefit of UTA/monopod combination was a very worthwhile 2.5 fold increase in detail compared to the handheld binocular alone which was just short of the 3x I could get with a tripod.
Of course a test chart can’t tell you everything. I tried several combinations round the field and hedgerows near where I live, but mostly used my 8x42 further afield including a nice morning over at Lee valley lakes. The boost obviously make the target look bigger and hopefully allows you to see smaller detail, but spotting birds nestled down in the vegetation, or silhouetted against surface reflections is a different matter. The day was rather cloudy, and although the light levels were fine for the majority of the view, it did present some challenges in the shadows of the trees or against dark foliage. That aside, the benefits of the UTA and monopod were pretty obvious. There was a tight flotilla of canada geese about quarter of a mile away and at 8x it was difficult to make out individuals where they were clustered together, but boosted you could. I could pick out the separate tufts on the head of a great crested grebe with the UTA that were just a blur without. By eye, I could see a couple of white birds at the water’s edge at perhaps 400yds. At 8x I could see one was a little egret and the the other probably a gull. Boosted, it’s black head was very obvious. The differece meant I could actually see what a distant heron was catching. It was rather more testing spotting the Gadwall nesting in the scrubby grass, but a bit more sunshine fixed that. All in all, a very useful tool to have in the bag.
Even the very best binocular/UTA combination will still be easily beaten by a good 50mm travel scope, like Opticron’s own MM3, on magnification, contrast and fov, but that’s not really the point of a UTA. For me it’s a low cost stand-in for when you really want to leave that scope and tripod at home. I do quite a bit of walking, so that’s quite a lot of the time. Excellent!
David
P.S. Check out Chris Galvin’s demonstrations on Twitter. https://twitter.com/opticronuk[/QUOTE]
I’ve spent quite a few hours over the last couple of weeks trying to figure out exactly what the UTA can and cannot do and filled up half a dozen pages of my note book with calculations and tables of figures. You’ll be relieved to hear that I’ve decided to leave most of those where they are, and concentrate of the key points.
http://www.opticron.co.uk/Pages/uta_2x.htm
The UTA comes with just a single lens cap and a wrist strap. I’ve been using a small draw-sting bag that came with some sunglasses for a bit of protection when out and about. Without the connecting ring the UTA is 88mm long 33mm wide and weighs 148g on my kitchen scale. The ring adds about 23mm in length and a bit more to the width. It’s perhaps a little bigger than I expected but still a good size for a jacket pocket or the corner of a bag. The eye relief is approximately 20mm but the eye lens is recessed another 12mm which seems a curious design choice. The eyecup extends 10mm in three stages, but the mid point indents are a bit soft and liable to collapse.
Opticron have of 8 connector rings to fit their range of binoculars and eyepieces. They sent me the one for my Opticron Classic 7x36 and another 3 in the hope that they would work with the other binoculars I own. With a little bit of diy I got satisfactory fits for all my full size models, but learned you really shouldn’t twist them on with glued on eyecups!
Opticron's previous UTA was 2.5x which I thought too high, making the view a bit dim and soft for my taste. Balancing up instrument resolution, the exit pupil diameter and the eyesight of the user is tricky and even a 2x I feel would be pusing practical limits. I estimated that the UTA’s magnification is actually 1.8x which I think is just about perfect for an 8x42 or 10x56, but even for this level of boosting, light levels need to be somewhat higher to get satisfactory results for a 10x42 for example.
In decent light and mounted on a tripod, I could see 1.8x smallet detail using the UTA than the binocular alone. However the extra boost can take the view close to the resolution limit of even better binoculars and will exceed that of some. As a consequence I could spot differences in contrast at the limit of detail with different models as a result, but I think most will find it entirely satisfactory with most binoculars in the field. I should stress it’s binocular resolution that is limiting, not the UTA.
When used alone, the UTA has about a 35° AFOV but with my 7x36 and 8x42 it’s a pretty modest 27° which is less than half that you might expect from binoculars alone or a decent scope. At least with my flat field binoculars the view is sharp edge to edge. On a positive note, the boosting actually appears to improve close focus a little.
Although I found I could get a very useful increase in the level of detail when used hand held, I feel you really need additional support to get the full benefit of the extra magnification. Bracing againt a post or a rail will make quite a difference. No doubt, a sturdy tripod is the best solution, but for me, a lightweight monopod is the more natural partner for those who prefer to travel light. Quite how much benefit you’ll get will vary with user and the binocular but for my 8x42 for example, the practical benefit of UTA/monopod combination was a very worthwhile 2.5 fold increase in detail compared to the handheld binocular alone which was just short of the 3x I could get with a tripod.
Of course a test chart can’t tell you everything. I tried several combinations round the field and hedgerows near where I live, but mostly used my 8x42 further afield including a nice morning over at Lee valley lakes. The boost obviously make the target look bigger and hopefully allows you to see smaller detail, but spotting birds nestled down in the vegetation, or silhouetted against surface reflections is a different matter. The day was rather cloudy, and although the light levels were fine for the majority of the view, it did present some challenges in the shadows of the trees or against dark foliage. That aside, the benefits of the UTA and monopod were pretty obvious. There was a tight flotilla of canada geese about quarter of a mile away and at 8x it was difficult to make out individuals where they were clustered together, but boosted you could. I could pick out the separate tufts on the head of a great crested grebe with the UTA that were just a blur without. By eye, I could see a couple of white birds at the water’s edge at perhaps 400yds. At 8x I could see one was a little egret and the the other probably a gull. Boosted, it’s black head was very obvious. The differece meant I could actually see what a distant heron was catching. It was rather more testing spotting the Gadwall nesting in the scrubby grass, but a bit more sunshine fixed that. All in all, a very useful tool to have in the bag.
Even the very best binocular/UTA combination will still be easily beaten by a good 50mm travel scope, like Opticron’s own MM3, on magnification, contrast and fov, but that’s not really the point of a UTA. For me it’s a low cost stand-in for when you really want to leave that scope and tripod at home. I do quite a bit of walking, so that’s quite a lot of the time. Excellent!
David
P.S. Check out Chris Galvin’s demonstrations on Twitter. https://twitter.com/opticronuk[/QUOTE]
