Blurry black edge in SFL 8x30 ? (1 Viewer)

[FVG]

Earlier this year I replaced my Nikon M7 8x30 with a Zeiss SFL 8x30. What strikes me is that in the Nikon I always had razor-sharp black edges around the image (are those the eyepiece or the lens edges?) which gave a tidy overall image. But in the Zeiss that black edge is blurry. When I push the SFL deeper into my eye sockets, the edge becomes sharper but I quickly get annoying blackouts. The blurry black edges are not annoying or limiting, but it gives a somewhat cloudier overall image (not in the center of course).
I was wondering if other SFL (8x30) owners recognize this?
Fred

 

[hgalbraith1949]

Recently I was comparing 8x32 NL Pures and SFL in an optics shop in Massachusetts. I noticed right away that the former had crisp edges (the field stop?), whereas the SFL had blurred edges. This weighed in my decision to buy the swaros.

 

[William Lewis]

I find this all the time with a lot of binoculars I use.

It's not specific to the sfl just an ergonomic thing dependent on face shape and eye relief. It happens much less with binoculars with a narrower apparent field of view though.

I never had a problem with my old habicht 7x42 but its definitely apparent with my SLC 8x56 and Nikon e2 although interestingly to about the same degree despite their very different apparent fov and eye relief specifications. This makes me suspect it's something to do with the optical design as well as just ergonomics/afov/eye relief.

Personally although I'd like a crisp circle around the eye piece field stop I'd prefer a slightly rougher edge and no black outs as i find the black outs affect my enjoyment of a binocular much more adversely. It's not just glasses wearers that sometimes can't see the whole fov!

Will

 

[Mikbul]

Earlier this year I replaced my Nikon M7 8x30 with a Zeiss SFL 8x30. What strikes me is that in the Nikon I always had razor-sharp black edges around the image (are those the eyepiece or the lens edges?) which gave a tidy overall image. But in the Zeiss that black edge is blurry. When I push the SFL deeper into my eye sockets, the edge becomes sharper but I quickly get annoying blackouts. The blurry black edges are not annoying or limiting, but it gives a somewhat cloudier overall image (not in the center of course).
I was wondering if other SFL (8x30) owners recognize this?
Fred

Sounds like the field stop is out of focus. The field stop in my Nikon MHG is razor sharp.

 

[Ratal]

Field stop in my Zeiss VP 8x25 and Opticron Aurora are both razor sharp

 

[dorubird]

Earlier this year I replaced my Nikon M7 8x30 with a Zeiss SFL 8x30. What strikes me is that in the Nikon I always had razor-sharp black edges around the image (are those the eyepiece or the lens edges?) which gave a tidy overall image. But in the Zeiss that black edge is blurry. When I push the SFL deeper into my eye sockets, the edge becomes sharper but I quickly get annoying blackouts. The blurry black edges are not annoying or limiting, but it gives a somewhat cloudier overall image (not in the center of course).
I was wondering if other SFL (8x30) owners recognize this?
Fred

In binoculars or astronomy eyepieces I really admire the very sharp clear field stop and thin as a hair. This contributes a lot to the aesthetics of the AFOV of a binocular. It can be an eliminatory criterion when you are undecided between several binoculars.
I don't know about SFL 8x30 field stop and thank you for the clarification you made about its field stop! But I am also curious about other experience with this SFL 8x30 field stop.
I've experienced many field stop binoculars that aren't exactly thin hair sharp, with slightly blurred line transition to black, for example: Nikon E2 8x30 field stop and Zeiss VP 8x25 field stop... With these, I saw a faint blurred field stop without contrasting delimitation. Instead, in the order of sharpening of field stop: with Leica Ultravid 8x20 I saw the clearest sharp thin hair field stop. With Nikon HG 8x30 and Zeiss SF10x42 I saw a very beautiful field stop with a sudden delimitation between AFOV and external black but nos as Leica. Besides Leica Ultravid 8x20, the champion in the field stop beauty is also Swarovski Habicht 7x42... which not only has a very sharp field stop, but I can see a very large area of black outside the AFOV, which creates the illusion of even greater contrast between the AFOV and the black exterior!

 

[FVG]

I'm glad to see that the phenomenon of a blurry (black) edge occurs in more makes and models and that there is a term for it; "fieldstop sharpness". Strange that I have never seen a test or review of binoculars that discussed this. Because "field stop sharpness" is something different from "edge to edge sharpness"? Or perhaps it is more dependent on face shape and eye relief. Because I read that Rataal has a razor-sharp field stop with the Zeiss VP 8x25 and Doruvogel with the same Zeiss hasn't.

 

[dorubird]

It's about the quality of the field stop that is seen. Of course, if you can't see the field stop at all, that's due to insuficient eye relief.
So Field stop sharpness has nothing to do with "edge to edge sharpness" or eye relief. It's not about whether we see the entire AFOV to the edges or not due insuficeint eye relief. But field stop sharpness depends on its exact position in the optical path not eye relief.
There is another fact that can influence the perception of the field stop, namely whether the person has astigmatism or not. If the person has astigmatism and does not use corrective glasses, then the field stop can be seen blurred.

 

[William Lewis]

I don't think this is the case. If you move your eyes around with virtually any binoculars so you see the edge of the field stop they are all sharp - well almost all, in my old carton 10x50's there is a patch of roughness to the casting.

 

[Mikbul]

It's about the quality of the field stop that is seen. Of course, if you can't see the field stop at all, that's due to insuficient eye relief.
So Field stop sharpness has nothing to do with "edge to edge sharpness" or eye relief. It's not about whether we see the entire AFOV to the edges or not due insuficeint eye relief. But field stop sharpness depends on its exact position in the optical path not eye relief.
There is another fact that can influence the perception of the field stop, namely whether the person has astigmatism or not. If the person has astigmatism and does not use corrective glasses, then the field stop can be seen blurred.

As I said above, the field stop is out of focus, or as Dorobird put it, "exact position in the optical path".

 

[james holdsworth]

Is this really a thing? Henry?

 

[[email protected]]

Earlier this year I replaced my Nikon M7 8x30 with a Zeiss SFL 8x30. What strikes me is that in the Nikon I always had razor-sharp black edges around the image (are those the eyepiece or the lens edges?) which gave a tidy overall image. But in the Zeiss that black edge is blurry. When I push the SFL deeper into my eye sockets, the edge becomes sharper but I quickly get annoying blackouts. The blurry black edges are not annoying or limiting, but it gives a somewhat cloudier overall image (not in the center of course).
I was wondering if other SFL (8x30) owners recognize this?
Fred

Can you take a picture with your cell phone through the ocular of what you are observing?

 

[tenex]

Because I read that Rataal has a razor-sharp field stop with the Zeiss VP 8x25 and Doruvogel with the same Zeiss hasn't.

Curious, although two observers may not be applying the same standard of sharpness.

I haven't tried SFL 30 (only 40) but wouldn't expect to see a fuzzy field stop in a quality binocular, so while thinking about the distinctions Dorubird drew above, I tried a couple of mine. The field is so wide in E II 8x30 that at a proper eye distance, I can barely see the stop at all, but it certainly looks fine to me. (I don't wear specs.) My SLC 10x42 has a more modest field, but still I don't feel I can evaluate the stop precisely. The difficulty is that I can't focus directly on the stop while keeping the instrument aligned in a normal viewing position, and tilting it would render the result invalid. If it were significantly out of position it would look obviously blurry even in peripheral vision, but I've never had such a binocular.

 

[FVG]

Can you a picture with your cell phone through the ocular of what you are observing?

I'll try it one of these days.

 

[FVG]

For anyone who has doubts about the SFL 30, I say again: the blurred fieldstop in my SFL 30 is not so annoying that it hinders my viewing pleasure. Moreover, the Zeiss has qualities that make me forget my Nikon, such as the much better handling of glare and the easier eye placement. I really wanted 8x30 binoculars and I think the Zeiss is about the best available.

 

[Mikbul]

Is this really a thing? Henry?

Don P. answers out of focus field stop. It may actually be your eyes, not the eyepiece. BTW binocular eyepieces are basically the same as telescope eyepieces.
A reticle eyepiece is adjustable because the reticle is at the field stop and every ones eye are different. If you have ever looked thru a riflescope you know what I mean, you have to focus the reticle for YOUR eyes. Bino eyepiece field stops are more than likely set for 20-20 vision.

https://www.bing.com/ck/a?!&&p=6d7a334d788e5345JmltdHM9MTY5NDMwNDAwMCZpZ3VpZD0xMGZhYzZiNy04Yjk0LTYwMjAtMTZjNy1kNTM0OGFmNjYxNDMmaW5zaWQ9NTIwMA&ptn=3&hsh=3&fclid=10fac6b7-8b94-6020-16c7-d5348af66143&psq=eyepiece+field+stop+out+of+focus&u=a1aHR0cHM6Ly93d3cuY2xvdWR5bmlnaHRzLmNvbS90b3BpYy81NDg3MDMtYWRqdXN0aW5nLXRoZS1maWVsZC1zdG9wLWZvY3VzLWluLWEtdGVsZXZ1ZS1kZWxpdGUtZXllcGllY2Uv&ntb=1

 

[b-lilja]

Definitely a thing with the 8x30SFLs, but it doesn't keep me from appreciating its other unique virtues.