I've owned a pair of SLC 15x56 for just over a week and used them daily apart from one day of woodland birding where my SLC 7x50s were a more obvious choice.
Let's get the bad news out of the way - these are incredibly heavy to carry round the neck even with the very good ladder lock strap. 30 minutes is mildly uncomfortable, two hours bearable but my neck suffered for it for the rest of the day, and I'm used to carrying heavier bins or camera gear. Anyone who can carry these round their neck for a day's birding deserves a medal. If you want a rough idea of the weight - but two glass bottles of beer (330ml /12oz) tape them together (full) and hang round your neck - you'll soon be wanting to empty them.
The big surprise - for me these are perfectly usable handheld for short periods. I've struggled with many a 10x, particularly 10x25's and 10x30s, but the extra weight, thumb grips and overall balance works miracles. They're absolutely fine for shorter views - id checks and observation up to a minute or so within the distance range I'd use a 10x. I wouldn't want to hold them for a very long observation, but in normal use they're fine. Handheld I can't make clear ids much beyond the reach of a 10x - I just get larger fuzzy blobs, but they effectively work as well as 10x but with the bonus of a lens filling view of birds.
I bought the silly priced SLC tripod mount and they're clearly even better on a tripod, allowing more distant ids, although note heat haze can become a limiter (yes even on UK day in April). The tripod mount works extremely well, and with an email to Swarovski asking about purchasing an extra stud for my 7x50s they sent me one free of charge - great service.
Obviously with this magnification they haven't got the widest field of view I think it's 62 degrees apparent or 78m at 1000m but I can't say it caused any real problems in finding birds or following birds in flight. Similarly they're not close focus - I'd estimate a little over 3m in real life rather than the slightly longer spec, but obviously you don't need to get as close to get the same size view. Not a binocular I'd choose for insect watching, but for birdwatching fine, and you can keep a greater distance between you and a flighty subject. For me they worked really well with observing small passerines.
Construction feels bombproof and I like the lightly textured armour - no problems getting a good grip. I've larger hands but with hands roughly in a thumbs up position (but with thumbs angled towards me) I coulld hold the barrels near the objective, have thumbs in the depression and still focus with an index finger. The focusing is typical Swarovski - perfectly smooth, even and precise but with quite long travel from close range to infinity - if you like the less precise faster travel some manufacturers use these might not be for you. I did wonder whether the narrower dof this magnification gives would be an issue, but in practice I found it helped isolate birds in bushes from the bush.
Eye cups are pretty standard - comfortable and hold their position. Eye relief felt good - as a non-glasses wearer I needed the cups extended about half way to prevent kidney beans. A glass wearing friend had no issues. The big objectives mean eye placement is a non-issue and you barely notice the circular edge - it's a very immersive view.
I've no idea what the measured transmission of these is - I'd guess low 90's - the AK prisms certainly deliver a very bright pair of binoculars. I've not tried them at dusk, but the 3.7mm exit pupil was completely adequate even on a very dull and overcast day.
The image is to my eyes perfectly neutral with no colour cast, and contrasty. Sharpness is excellent almost edge to edge, very close to NL levels and with a near flat field. They're effectively CA free - trying hard to induce it I could just detect it on the last 5% viewing a power cable against a near white sky, but otherwise in a week's use I didn't spot any at all - they're as free from false colour as any binoculars I've used. Optically I don't think anyone would have any complaints
Supplied case is good, lift strap is amongst the best straps I've used and proper lugs no pointless fieldpro system!
Final thoughts - yes unbelievably this magnification can be handheld, and these are more stable than many 10x in my hands. Image quality is excellent and they're even better on a tripod - I think my little ED50 is largely retired. I'm seriously tempted to use these where I'd normally use my 10x, but there's no getting around it the weight is an issue. I've got to either swallow my dislike of bino harnesses and go that route (assuming that makes prolonged use comfortable enough) or limit them to very short walks and tripod use.
Let's get the bad news out of the way - these are incredibly heavy to carry round the neck even with the very good ladder lock strap. 30 minutes is mildly uncomfortable, two hours bearable but my neck suffered for it for the rest of the day, and I'm used to carrying heavier bins or camera gear. Anyone who can carry these round their neck for a day's birding deserves a medal. If you want a rough idea of the weight - but two glass bottles of beer (330ml /12oz) tape them together (full) and hang round your neck - you'll soon be wanting to empty them.
The big surprise - for me these are perfectly usable handheld for short periods. I've struggled with many a 10x, particularly 10x25's and 10x30s, but the extra weight, thumb grips and overall balance works miracles. They're absolutely fine for shorter views - id checks and observation up to a minute or so within the distance range I'd use a 10x. I wouldn't want to hold them for a very long observation, but in normal use they're fine. Handheld I can't make clear ids much beyond the reach of a 10x - I just get larger fuzzy blobs, but they effectively work as well as 10x but with the bonus of a lens filling view of birds.
I bought the silly priced SLC tripod mount and they're clearly even better on a tripod, allowing more distant ids, although note heat haze can become a limiter (yes even on UK day in April). The tripod mount works extremely well, and with an email to Swarovski asking about purchasing an extra stud for my 7x50s they sent me one free of charge - great service.
Obviously with this magnification they haven't got the widest field of view I think it's 62 degrees apparent or 78m at 1000m but I can't say it caused any real problems in finding birds or following birds in flight. Similarly they're not close focus - I'd estimate a little over 3m in real life rather than the slightly longer spec, but obviously you don't need to get as close to get the same size view. Not a binocular I'd choose for insect watching, but for birdwatching fine, and you can keep a greater distance between you and a flighty subject. For me they worked really well with observing small passerines.
Construction feels bombproof and I like the lightly textured armour - no problems getting a good grip. I've larger hands but with hands roughly in a thumbs up position (but with thumbs angled towards me) I coulld hold the barrels near the objective, have thumbs in the depression and still focus with an index finger. The focusing is typical Swarovski - perfectly smooth, even and precise but with quite long travel from close range to infinity - if you like the less precise faster travel some manufacturers use these might not be for you. I did wonder whether the narrower dof this magnification gives would be an issue, but in practice I found it helped isolate birds in bushes from the bush.
Eye cups are pretty standard - comfortable and hold their position. Eye relief felt good - as a non-glasses wearer I needed the cups extended about half way to prevent kidney beans. A glass wearing friend had no issues. The big objectives mean eye placement is a non-issue and you barely notice the circular edge - it's a very immersive view.
I've no idea what the measured transmission of these is - I'd guess low 90's - the AK prisms certainly deliver a very bright pair of binoculars. I've not tried them at dusk, but the 3.7mm exit pupil was completely adequate even on a very dull and overcast day.
The image is to my eyes perfectly neutral with no colour cast, and contrasty. Sharpness is excellent almost edge to edge, very close to NL levels and with a near flat field. They're effectively CA free - trying hard to induce it I could just detect it on the last 5% viewing a power cable against a near white sky, but otherwise in a week's use I didn't spot any at all - they're as free from false colour as any binoculars I've used. Optically I don't think anyone would have any complaints
Supplied case is good, lift strap is amongst the best straps I've used and proper lugs no pointless fieldpro system!
Final thoughts - yes unbelievably this magnification can be handheld, and these are more stable than many 10x in my hands. Image quality is excellent and they're even better on a tripod - I think my little ED50 is largely retired. I'm seriously tempted to use these where I'd normally use my 10x, but there's no getting around it the weight is an issue. I've got to either swallow my dislike of bino harnesses and go that route (assuming that makes prolonged use comfortable enough) or limit them to very short walks and tripod use.