IMO one of the reasons to own a SV 8.5X42 is that it bridges the 8X/10X gap a little.
I actually use the SV 12X50 more now than I did previously. IMO a perfect compliment to a nice 7X/8X. You'd be surprised how often there is something close to lean on or to use for a prop.
I think I'd wait on selling that 7X42 Leica!:eek!:
In response to Torview and Pileatus, I had the chance to compare the 10x50SV vs. it's 12x50 counterpart over the last two days. Spent all day Sunday on Galveston Bay and High Island. Lots of time with birds in flight and long distance views out across the water with both a finnstick and a binocular harness. Spent last night for several hours on the night sky comparing as well.
Chuck makes a great point that the 8.5x42 bridges the gap between 8x/10x very nicely. It's a very slight, but noticeable increase in magnification over an 8x roof. When going back and forth between the 8.5x and 10x, there just was not that much difference. Of course, the 10x is only a 17.6% increase in magnification over the 8.5x. The 12x is a 41% increase over the 8.5x. Very noticeable difference.
Another comparison I made was on the night sky comparing the 12x50SV to what has long been my favorite astronomy bin, my Nikon 12x50SE. The increase in FOV of the 12x SV over the SE was very apparent. Such a great view (although the 10x50SV with its wider FOV is pretty incredible on the night sky as well).
As far as ease of view as well as ease of use, here are my observations. The 10x has an incredible WOW factor (I've seen that stated many times here, and it's true). The 12x is not quite as impressive at first glance, but the 12x is just as sharp, and has essentially the same AFOV.
By themselves, I would probably gravitate more toward the 10x50SV. Having said that however, I didn't notice a great difference in my ability to hold the 10x any more steady than the 12x. For handheld use, I use a Rick Young Outdoors binocular harness, which gives me just enough support to easily use either power for extended views. And for terrestrial use neither one of these will serve as my primary bin. On the night sky I will have it mounted next to my Lafuma zero gravity chair, and I find ALL handheld 10x bins a little difficult to hold steady on stars for any length of time. For quick handheld use at night, the ease of use is equal in both bins.
Another consideration in my decision is the fact that I also own the unbelievable Swaro 10x40 Habicht GA. It's smaller, lighter and in many ways easier to use than the 10x50SV. However, I don't use it much as it is my son's primary bin. But, it is redundant with two great 10x bins. The other kicker for me is that the 12x SV is so much nicer on the night sky than my 12x SE, a bin I thought could never be beat for astronomy.
If my primary bin was a 7x42 (which was the case for me until recently) or a 8x32, it would be a "no brainer" to choose the incredible 10x50SV, but I am leaning heavily on buying the 12x50SV and selling the 10x50SV, for three main reasons:
1.) I feel the 12x is a better compliment to the 8.5x with a greater spread of magnification over 10x/8.5x combo (And yes Chuck, I'm keeping a 7x, however it will be my Zeiss FL over the UV+ due to wider FOV and Abbe Koenig brightness).
2.) For astronomy, 12x SV really impressed me over my long-time favorite 12x SE. Very noticeably wider FOV and even flatter field than the SE, which is great on the night sky.
3.) The 12x SV is the same size and weight as the 10x, and it is just as easy to use. For longer range birds in flight, there is no difference in shake when panning, but the magnification is just enough to make a difference. For times that I use a finnstick or monopod, the problems of higher magnification are negated.
Torview started this thread to highlight his experience after a year with the 8.5x42SV. I share his conclusions. More importantly for me, using the 8.5x42 as my primary bin has shaped how I put together the rest of my collection as well. I don't usually like to have redundant bins (although I can appreciate the characteristics of different, but similar mag optics).
My collection will now be:
7x42 Zeiss FL (Great for low light and sporting events with wide FOV)
8x30 Habicht (Love it for hummingbirds in the backyard and as a travel bin)
8.5x42SV (Primary bin, nothing better AFAIK)
10x40 Habicht (Makes the 12x50 decision easier, and my son loves it!)
12x50SV (Beautiful SV view and compliments the 8.5 perfectly. Great Astro bin)
18x70 Nikon Astroluxe (incredible high power Astro bin)