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8x42 vs. 10x50 dawn/twilight (1 Viewer)


Well-known member
Ok, you've got me, Jerry, I'll have to give a pair of these a go...

I've been trialling a pair of 8x56 SLC's to use as my low light binoculars, but we're not getting on too well, mainly due to the lack of intermediate click stops on the eyecups. Yes, I could probably adapt them with o-rings, but I like a glass (especially an expensive one) to work for me straight out of the box, without having to be adapted. That's just me. Extraordinary glass in low light, really, but they've got to go. (I note William Lewis is letting his recently acquired copy go too, which surprised me).

I know eye relief will be tight, but having recently discovered that I can easily use (and see full FOV) an Ultravid 8x32 or Kowa Genesis 8x33 wearing glasses, I'm confident that these should work for me.

The search is on...
If you can get on with the 8x32 Ultravid wearing glasses, you must be near-sighted.
I am far-sighted and find even the eye relief of my 8x33 Genesis to be suboptimal.
I can also appreciate your "problem" with the 8x56 SLC. To avoid blackouts wearing glasses I have to extend the eyecups about 2 mm beyond the first stop and guess you would be closer to the second stop. This though is a minor irritation on a binocular that has some qualities unmatched by any other centre focus binocular.
A friend has an 8x42 NL, which is an amazing optical achievement with its wide flat field and ergonomicaly it is also excellent, but if an exchange were on the cards, nothing could persuade me to part with my 8x56 SLC.


PS: Tenex was having problems with blackouts with his 10x56 SLC and I suggested he procure some 8x56 eyecups. These solved the problem. I suppose I could go the other way, but it would then make the 8x56 unusable for anyone without glasses.


Yes, I have John to thank for that suggestion. It does seem quite possible (given the reduced range) that the second stop of the 10x eyecups might correspond to "2mm beyond your first stop" and work conveniently for you, but you'd have to try it to see. I wouldn't worry too much about making the 8x56 unusable for others because you'd still have the originals, and with such high ER it's unusable for some like me anyway.

I've always wondered why the 8x56 should have 23mm ER, so much more than anyone could possibly need. There's usually a trade-off between ER and FOV, so couldn't it have had a wider field instead? I must be missing something here.


Well-known member
United Kingdom
Hi Bentley 03

I didn't want to part with them but thankfully the wife has allowed them to stay, few financial bumps in the road!

I know what you mean about eye cup position on them though - tricky! I use the last but one click stop which is actually one click ( approx 2mm) further out than the last click stop - the difference between that and the final click stop seems the smallest gap between stops so I think I'm lucky that's the one that fits.

There's been some discussion recently highlighting that the eye cups for the 8x 10x and 15x are all interchangeable and I believe that swaro may well provide them free of charge so depending on your needs you may be able to find a "factory fit" work around.

All the best

Will, I'm very pleased to hear you are keeping them, your enthusiasm for them was very apparent!

Ideal eyecup position for me (with glasses) is somewhere between the first and second clicks up. The gap between them is enormous, with more than adequate relief for at least one more intermediary stop. I find them very usable when set at the first stop if the target is stationary, but anything which requires panning or pointing up to the sky puts me in all sorts of trouble. Given that these are not intended as a daytime binocular, simply too big and heavy for long walks, I think the investment is excessive for an instrument which will be used infrequently that doesn't fit me perfectly. That said, for their size, they do handle really nicely, once you get to grips with them, and the focus wheel in this copy is at a different level from any SLC's I've ever used before, absolute perfection, just not as buttery smooth as an NL or SF.

I really appreciate your suggestion of swapping out the eyecups with the those of one of the other x56 models, it may well have made the difference for me, but I've already let them go.

All the best,


Well-known member
United Kingdom
John and Tenex, thank you very much for your suggestions, it's really appreciated.

As you'll have gathered from my previous post, I've already parted company with them. That said, I may revisit them at some point (in the quite near future), because as the days get shorter, I'll be walking in darker conditions, and into darkness, more frequently. Optically, I agree, they have special qualities, but they are a big old lump to carry around for any length of time. But, I do really, really like them. I do need to justify owning them though.

My interest has come about after discovering my eye pupils have rather more agility than I anticipated (for my age), so I'm keen to explore low light optics while I still have the ability to take advantage of a large exit pupil. I'm going to experiment with some older large objective instruments over the Winter, but I have a suspicion my journey may well end with another pair of 8x56 SLC's.

All the best,

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