New Swarovski SLC 42 Binoculars (14 Viewers)

[elkcub]

All of the Minox HG have that feature, not just the big 10x52. I haven't tried the Minox, but I own and have used the Pentax a lot. Given its 18" close focus, focusing would be a real chore in the close range (or too course at distance) if it didn't have a variable (or dual) ratio focus. I've tried the Brunton Epoch on numerous occasions and the focus from the close limit of 3 feet to infinity is smooth, precise, and works so well it does not to call attention to itself. I'm not a fan of the Epoch for other (optical) reasons, so I don't own one.

--AP

My impression from what you've said is that the gear ratio change is continuous rather than discrete for the Minox and Brunton. The Pentax might be continuous or discrete, i.e., "dual." It that right? Of course continuous or discrete makes a big difference in what we can infer about the mechanism. Perhaps both are in use.

In any event, contrary to strong assertions made earlier in the thread, it would appear that variable ratio focusers are alive and well. Now the question becomes whether the SLC HD is one of them; I doubt it.
But, I can use what it has quite effectively in the near region, and that capability doesn't interfere in the least with normal ranges. Quite a package.

Ed

 

[The Kingfisher]

Today I had the opportunity to compare the focus speed between the Nikon EDG and the old SLC HD. From infinity to 10 meters the EDG was about 40% faster (140 vs. 240 degrees) than the old SLC HD. However, I never measured from 3 km to 10 meters, but I guess the difference would still be about the same between the two.

Now, if the old SLC HD would be twice as fast as the new SLC the wheel on the latter should rotate 480 degrees. Right? But I do not get it together properly because the focus wheel on the new SLC has a maximum rotation about 450 degrees (note it is all the way down to 3.2 meters and not just to 10). I feel like a big question mark now I must say. Does anyone have a good explanation for this?

 

[elkcub]

Today I had the opportunity to compare the focus speed between the Nikon EDG and the old SLC HD. From infinity to 10 meters the EDG was about 40% faster (140 vs. 240 degrees) than the old SLC HD. However, I never measured from 3 km to 10 meters, but I guess the difference would still be about the same between the two.

Now, if the old SLC HD would be twice as fast as the new SLC the wheel on the latter should rotate 480 degrees. Right? But I do not get it together properly because the focus wheel on the new SLC has a maximum rotation about 450 degrees (note it is all the way down to 3.2 meters and not just to 10). I feel like a big question mark now I must say. Does anyone have a good explanation for this?

That's fairly remarkable. It took you 240˚ to go from inf. to 10m (=33ft) with the SLC HD? It takes me and Kimmo's friend 90˚, and Kimmo himself 130˚. Are you sure you were measuring to 10m and not to 10ft with the SLC HD?

Of course, you're in Sweden where meters would be natural.

Ed

 

[brocknroller]

All of the Minox HG have that feature, not just the big 10x52. I haven't tried the Minox, but I own and have used the Pentax a lot. Given its 18" close focus, focusing would be a real chore in the close range (or too course at distance) if it didn't have a variable (or dual) ratio focus. I've tried the Brunton Epoch on numerous occasions and the focus from the close limit of 3 feet to infinity is smooth, precise, and works so well it does not to call attention to itself. I'm not a fan of the Epoch for other (optical) reasons, so I don't own one.

--AP

Too bad about the Epoch, I like the idea of variable-speed focusing and wish it had been adopted by a lot of other companies. The Epoch is unique looking with its black rubber nibs and white clown bib. I'm surprised that the Epoch sells for $1,600 and even more surprised that the company's top model the Epoch MD sells for $2,700! I think they sold two so far (with a steep in-house company discount .

What do you find lacking optically about the Epoch?

--BP

 

[The Kingfisher]

That's fairly remarkable. It took you 240˚ to go from inf. to 10m (=33ft) with the SLC HD? It takes me and Kimmo's friend 90˚, and Kimmo himself 130˚. Are you sure you were measuring to 10m and not to 10ft with the SLC HD?

Of course, you're in Sweden where meters would be natural.

Ed

Yes, I measured to meters. Its very strange..if I did the measuring right of course. But I did it twice and a cousine got the same result when she was measuring. She is nearsighted like me. I will do the test again today..

But did you do the test from INFINITY to 10 meters? Maybe it was from 3 km to 10 meters?

 

[elkcub]

I'll walk it off and make sure. :-0

Yup, 10m to INFINITY. Just got back.

Ed

 

[The Kingfisher]

I'll walk it off and make sure. :-0

Maybe we should talk about minutes on a clock instead of degrees? :-D For me it took about 35-40 minutes for the SLC HD to go from infinity to 10 meters. For you it should only take 20-25 minutes because thats the same as 130 degrees.

 

[elkcub]

Maybe we should talk about minutes on a clock instead of degrees? :-D For me it took about 35-40 minutes for the SLC HD to go from infinity to 10 meters. For you it should only take 20-25 minutes because thats the same as 130 degrees.

I take 15 min. by that reckoning (90˚). Kimmo takes 20-25 min. Maybe your clock's running fast. :eek!:

 

[The Kingfisher]

I take 15 min. by that reckoning (90˚). Kimmo takes 20-25 min. Maybe your clock's running fast. :eek!:

My cousine just did the test again for me. She wrote that the wheel rotated more than 200 degrees..about 40 min on a clock! Very very strange..

 

[The Kingfisher]

One question for you...what do you guys mean with "infinity"? I mean thats the position where the focusing wheel can not be rotated any more . Maybe different SLC HD has different maximum rotations? The specimen I have done the measures on rotates about 2x360 degrees/120 min from infinity to 1,9 meters.

 

[Alexis Powell]

Too bad about the Epoch, I like the idea of variable-speed focusing and wish it had been adopted by a lot of other companies. The Epoch is unique looking with its black rubber nibs and white clown bib. I'm surprised that the Epoch sells for $1,600 and even more surprised that the company's top model the Epoch MD sells for $2,700! I think they sold two so far (with a steep in-house company discount .

What do you find lacking optically about the Epoch?...

The high price for the Epoch is certainly a mystery. They dropped the real world price (along with the close focus) for the standard Epoch to under $1000, but the MD is still priced over $2000. Who buys them? Probably folks who have money, respect the Brunton brand based on experience with other products, and who want a good bin but don't do much/any research on alternatives.

For me, the fatal flaw of the Epoch MD is the narrow FOV. What is the point of 3 ft close focus if the FOV is so narrow that the fields cannot overlap? I don't know about the MD or the new standard Epoch without close focus, but the older standard Epoch with 3 ft close focus also had too much CA for my taste.

--AP

 

[elkcub]

One question for you...what do you guys mean with "infinity"? I mean thats the position where the focusing wheel can not be rotated any more . Maybe different SLC HD has different maximum rotations? The specimen I have done the measures on rotates about 2x360 degrees/120 min from infinity to 1,9 meters.

Ah, ha. The infinity setting for you is where a very distant object is in focus. For me that point is 135˚ inward from the maximum rotation point, or wheel "stop." Being myopic, your personal infinity setting may be 90˚ inwards from the stop, or even less. If I don't wear my glasses the infinity point moves to about 155˚, accounting for 2-3 spectacle diopters. But, I assume you wear your glasses as I do.

Incidentally, each ridge on the SLC HD focusing wheel represents ten degrees of rotation, since there are 36 in all. I put a tape marker at the various positions corresponding to infinity, 10m, 5m, etc., and simply count between the markers. The picture shows my infinity position aligned with the fixed diopter mark on the binocular body. From the lower edge of the marker there are 9 ridges to the lower edge of the next marker, representing 90˚ from inf. to 10m.

Ed

 

[The Kingfisher]

Ah, ha. The infinity setting for you is where a very distant object is in focus. For me that point is 135˚ inward from the maximum rotation point, or wheel "stop." Being myopic, your personal infinity setting may be 90˚ inwards from the stop, or even less. If I don't wear my glasses the infinity point moves to about 155˚, accounting for 2-3 spectacle diopters. But, I assume you wear your glasses as I do.

Incidentally, each ridge on the SLC HD focusing wheel represents ten degrees of rotation, since there are 36 in all. I put a tape marker at the various positions corresponding to infinity, 10m, 5m, etc., and simply count between the markers. The picture shows my infinity position aligned with the fixed diopter mark on the binocular body. From the lower edge of the marker there are 9 ridges to the lower edge of the next marker, representing 90˚ from inf. to 10m.

Ed[/QUOTE

OK, there we have the answer! :-D But why exactly 135 degrees as infinity point?

 

[elkcub]

My friend, focus on a very distant point and mark where that is on the focus wheel. However many degrees that is from the wheel stop, that is your personal infinity setting, ... for that instrument. It will be different from mine, and it may even be somewhat different from other specimens of the same binocular.

Because people have differing visual limitations (you being myopic and me presbyopic, for example,) binoculars are designed with focus wheel over-travel. Without it, myopics in particular might have a very difficult time focusing on distant objects.

Hope that helps,
Ed

PS. Actually, it doesn't matter how many degrees in your inf. setting is from the wheel stop. What matters is that you use it as the reference point when changing to closer working distances.

 

[kabsetz]

Kingfisher,

Like Ed said, "infinity focus" would be where you see a very distant object perfectly focused. If you want to be exact about it, you need to focus on a star, but then keep in mind that your eyes will possibly have different focus in the dark than in the daylight. Since for most binoculars the focus travel from a distance of a couple of kilometers to true infinity is very small, I tend to use some buildings about 4 km away that I can see from my balcony as my "infinity" target. 10 meters I have measured indoors and can easily replicate.

All binoculars are designed so that they focus "past infinity" for a person with no myopia or presbyopia. This is because people with myopia who do not wear glasses while viewing will need to focus further to see the image in focus, whereas people with presbyopia like myself don't need to focus as far. As an example, the specifications Swarovski gives for the new SLC series has the SLC 42's focusing 4 dpt past infinity, the 8x56 5 dpt past infinity and the 10&15x56 models focusing 8 dpt past infinity.

Prior to these trials with the SLC HD and the new SLC, I had failed to consider the possibility that eye defects (prescription) would have a marked effect on focus speed, and was thus rather surprised when me and my friend got such different focus travel results for the same binocular and for same distances. We were standing side by side and focusing on the same targets, and repeated the tests a number of times. The difference in focus speed with one and the same binocular for us two different viewers was 1.44 fold. This is enough of a difference to make the binocular objectively slow focusing for one and fast focusing for the other (post #261 in this thread). Another surprise for me was when I tried this same test with my Nikon 10x42 SE at home, checking the needed focus travel from 10m-4km without glasses, with reading glasses and with glasses that give me perfect distance vision. I was expecting that with progressively stronger glasses, not only would focus setting for both of these reference distances change, but also the focus travel would shorten. However, for all three conditions the focus wheel turned about 170 degrees. Somebody wiser than me can explain why this is, but it now seems to me that focus speed is not only binocular dependent but also to a surprisingly large extent viewer dependent. Next, I'll try to ask my myopic wife and my daughter who does not wear glasses to test the same distances with the 10x42.

Kimmo

 

[elkcub]

Hi Kimmo,

I just confirmed, with the 8x SLC HD, that my points of best focus at inf. and 10m are displaced by ~20˚ of wheel rotation by not using glasses. The difference is a constant 90˚, however, so it doesn't effect "speed" per se.

Using my 7x42 BGAT*P, the wheel offset at inf. and 10m is ~1 diopter mark, or 22.5 degrees, again leaving a 90˚ rotation between the two markers.

I'm not much of an optometrist, but this focus offset may have to do with my astigmatism correction. At 10m I use an Edmund resolution chart to obtain best focus, which is quite consistent focusing from either direction. So, DOF is probably not a culprit.

Ed

 

[The Kingfisher]

Thanks a lot for the detailed information about "infinity". My new infinity point is a street light about 4-5 km away. I can not measure the old slc right now (I dont own it), but both Nikon EDG and the Nikon SE need a rotation of 90 degrees to focus down to 10 meters. I think thats a perfect speed. The new slc will maybe be slower in the theory and when measuring from infinity to 10 meters, but as I wrote earlier in this thread I do not think it will be a problem at all in the field. Not for me at least.. :-D

 

[The Kingfisher]

By the way..why have you chosen 10 meters as the closest focusing point?

If we are to compare the focus speed of the old SLC HD and the new SLC..should we not use 3.2 meters instead!? Would the old SLC HD still be twice as fast as the new one? Would it still be faster at all? Probably..or?

 

[elkcub]

By the way..why have you chosen 10 meters as the closest focusing point?

If we are to compare the focus speed of the old SLC HD and the new SLC..should we not use 3.2 meters instead!? Would the old SLC HD still be twice as fast as the new one? Would it still be faster at all? Probably..or?

Well, note that my charts went progressively to 10, 5, 3.6, and 2.4 meters. These distances correspond with 33, 16, 12, and 8 feet, respectively. Your new SLC should be compared down to 3.6m, and perhaps to the closest common focusing point. Again, the closest point will be specific to each observer.

If you can give me good readings, plus your finger digit length, I'll plug them into my spreadsheet and compare your push/pull workloads for the two binoculars.

Ed

PS. Those little tabs I put on the focus wheel come from the sticky part of Post-It notes, ... if you have those in Sweden.

 

[kabsetz]

By the way..why have you chosen 10 meters as the closest focusing point?

If we are to compare the focus speed of the old SLC HD and the new SLC..should we not use 3.2 meters instead!? Would the old SLC HD still be twice as fast as the new one? Would it still be faster at all? Probably..or?

Kingfisher,

I have chosen 10 meters for my testing perhaps randomly, but also for three reasons. None of the reasons are imperative, but here they are:

- In practical birding, I have found that I don't often have to quickly change focus from distant to much closer than 10 meters.

- Different binoculars have different closest focus limits, and it has only been in the past 10 years or less that binoculars focusing closer than about 4 meters have become commonplace. So, to be able to compare most all binoculars, 5 meters would be a practical minimum. That could be a better reference distance, but since I started using 10 many years ago, I've thought it better not to change procedures unnecessarily.

- 10 meters is a nice round number.

Kimmo