The Zeiss SFL 8x30 compared with select current 8x30/8x32 roof binoculars (2 Viewers)

[BertL]

Dear Canip,

Yes, so, after all, the 'Merlitz distortion' does in fact work out. I should get one of these SFL for the simple reason that their distortion curves were intentionally designed for smooth panning - quite amazing to realize how long it took until the panning (which is such a common process during observation) once again entered the merit functions of the optical designers. Even now, the spec sheets contain no entry that refers to the smoothness of panning. It is getting time to think about some sort of quality label which a binocular earns if its panning is pleasant. I will think about how that could be defined in a most simple and comprehensive way.

Thanks a lot for the nice comparison chart!
Holger

For the various SFL models it looks like the k value is all over the place. Not much of a design philosophy ?

 

[Holger Merlitz]

For the various SFL models it looks like the k value is all over the place. Not much of a design philosophy ?

The k-values, as calculated with the official specs, do indeed vary, being about 0.55 (8x30), 0.7 (10x30), 0.75 (10x40) and 0.8 (8x40). This seems to collide with the information I received from Zeiss, according to which the SFL binoculars 'have been designed to closely follow the k = 0.7 curve'. I don't know anything about the origin of these apparent discrepancies. Perhaps, the official specs of the 8x30 are somewhat off - the magnification might be 8.2 instead of 8, which would explain most of the deviation. So far they won't tell me, so I can't answer this question.

Cheers,
Holger

 

[Canip]

We may not

Perhaps, the official specs of the 8x30 are somewhat off - the magnification might be 8.2 instead of 8,

Perhaps we will not get away that easily, Holger.
On my sample, magnification appears to be something like 8.04x** (measured, as precisely as my eyes permit, with the dynameter), so only very slightly more then 8x. That may not explain the difference in k-value.

Canip

** assuming an effective aperture of 30 mm

 

[Holger Merlitz]

Thank you, Canip, for this verification of the magnification. Zeiss will have to explain these data, since they seem to (mildly) contradict their claim that the 8x30 has a k-value close to 0.7. Certainly, k ~ 0.55 is not that far off in terms of overall distortion, but the difference should be visible. Which is your visual impression - is the pincushion distortion of the 8x30 clearly stronger than the distortion of the other SFL models?

Cheers,
Holger

 

[Canip]

is the pincushion distortion of the 8x30 clearly stronger than the distortion of the other SFL models?

I wouldn’t say clearly, but I find it a bit stronger than in the 8x40. The 8x30 for me is still fine, the 8x40 is almost perfect (I don‘t know the 10x30 nor the 10x40).

 

[Holger Merlitz]

It would be great if Zeiss could publish exact values here. Every camera lens comes with a precise specification of its distortion curve, so why do they make such a secret out of the same thing when it comes to binoculars

Cheers,
Holger

 

[BertL]

It would be great if Zeiss could publish exact values here. Every camera lens comes with a precise specification of its distortion curve, so why do they make such a secret out of the same thing when it comes to binoculars

Cheers,
Holger

To my eyes, the SFL 8x30 is a very nice binocular. It reminder me a lot of the SLC 8X42 I used to have.

Anyway thanks for the response

 

[BertL]

A large FOV is just personal preference, but I bet if you polled 100 birders, it would be in their top three qualities desired in their binoculars. If it wasn't Zeiss and Swarovski would not have developed the SF and NL with their huge FOV. it is also a big reason Swarovski outsells most other binocular that and their reputation for being the best binocular in the world. What I don't understand is if there are no side effects like RB or poor panning from a huge FOV why wouldn't you want one? You can see more birds and the FOV doesn't feel as tunnel like. What advantages are there to a smaller FOV other than the size, weight and price of the binocular. I think some people rationalize it by saying they don't need a huge FOV when what they are really saying is I don't want to spend $3000 to get a huge FOV. Now if I had 4 binoculars laid out on a table and I said you pick anyone for free, and they were a MHG, SFL, Retro and an NL which one would you go home with? 😁

SFL

 

[Brink]

SFL

You ought to take the NL, sell it, then buy the SFL and pocket $1k.

 

[henry link]

I wouldn’t say clearly, but I find it a bit stronger than in the 8x40. The 8x30 for me is still fine, the 8x40 is almost perfect (I don‘t know the 10x30 nor the 10x40).

There's a hint suggesting stronger pincushion in the 8x30 than in the 8x40 found in the FOV specs (provided the Subjective Viewing Angle spec is an accurate measurement.) Notice that the difference in the Subjective Viewing Angles between the 8x40 and 8x30 is 5% (60º vs 63º), but the difference between the true FOVs is only 1.43% (140m vs 142m). That would be explained if there is less compression of the outer field in the 8x30, meaning less AMD and more pincushion.

 

[Paultricounty]

SFL

Wow, I’d love to do a poll on that.

 

[Dirkvanleur]

I
Ik heb de Zeiss SFL 10x30 nu 4 maanden in bezit en ik kan gerust zeggen, het is een prima handzame verrekijker, zeer makkelijk te bedienen met een bijzonder helder en scherp beeld.
vergeleken met mijn oude Steiner sky hawk pro 10x42

 

[Paultricounty]

I
Ik heb de Zeiss SFL 10x30 nu 4 maanden in bezit en ik kan gerust zeggen, het is een prima handzame verrekijker, zeer makkelijk te bedienen met een bijzonder helder en scherp beeld.
vergeleken met mijn oude Steiner sky hawk pro 10x42

I
Ik heb de Zeiss SFL 10x30 nu 4 maanden in bezit en ik kan gerust zeggen, het is een prima handzame verrekijker, zeer makkelijk te bedienen met een bijzonder helder en scherp beeld.
vergeleken met mijn oude Steiner sky hawk pro 10x42

misschien moet dit in de nederlandse taal thread

 

[Owlbarred]

As one, I recognize BF serves as a place for recovering (as distinct from recovered) gearheads. Surely not all, but many of us hang here for reasons a bit beyond buying a binocular for birding. Just to be clear...It is after all called Birdforum and we are the bino sub group... Just sayin.

In a weird way, it's sorta therapeutic watching others in the throes of this affliction. Is this our version of the "meeting"?

"My name is Tom and Im a gearhead..."

Don, become? Ha!

Guy cant have too many flashlights....

Well said -- in extreme cases hoarders substituted for collectors.

 

[Maljunulo]

Well said -- in extreme cases hoarders substituted for collectors.

Similar pathology, perhaps less extreme.

 

[BertL]

There's a hint suggesting stronger pincushion in the 8x30 than in the 8x40 found in the FOV specs (provided the Subjective Viewing Angle spec is an accurate measurement.) Notice that the difference in the Subjective Viewing Angles between the 8x40 and 8x30 is 5% (60º vs 63º), but the difference between the true FOVs is only 1.43% (140m vs 142m). That would be explained if there is less compression of the outer field in the 8x30, meaning less AMD and more pincushion.

I just compaired the SFL 8×30 with my Noctivid 8x42. They share almost the same k value.
The AFOV of the Noctivid is smaller on paper than the AFOV of the SFL, but to my eyes the image feels bigger in the Noctivid. The magnification of the SFL feels a little bigger.
The biggest difference is that the DOF in the Noctivid is enormous compared to the SFL. This gives a very transparant view. Following birds on the wing is much easier. The SFL needs more focusing.

The 3D of the SFL looks more apparent, but I think the smaller DOF and the bokeh create that feel.

The Noctivid is much sharper, specally at far distance. For me the Noctivid a better bino by far.
The SFL however comes close!!!! For the money it is an extremely good binocular.

I bought the SFL 8x30 for my long walks. It is light and a far better binocular than many compacts.

 

[Maljunulo]

The Noctivid is much sharper, specally at far distance. For me the Noctivid a better bino by far.

I’m curious how a binocular can be more “sharp“ at some distances, as opposed to other distances.

Please instruct and enlighten me.

 

[Paultricounty]

I just compaired the SFL 8×30 with my Noctivid 8x42. They share almost the same k value.
The AFOV of the Noctivid is smaller on paper than the AFOV of the SFL, but to my eyes the image feels bigger in the Noctivid. The magnification of the SFL feels a little bigger.
The biggest difference is that the DOF in the Noctivid is enormous compared to the SFL. This gives a very transparant view. Following birds on the wing is much easier. The SFL needs more focusing.

The 3D of the SFL looks more apparent, but I think the smaller DOF and the bokeh create that feel.

The Noctivid is much sharper, specally at far distance. For me the Noctivid a better bino by far.
The SFL however comes close!!!! For the money it is an extremely good binocular.

I bought the SFL 8x30 for my long walks. It is light and a far better binocular than many compacts.

That post just went against everything I thought I knew about DOF, transparency, 3D effect and distance observing, oh and bokeh 🤪✌🏼. I guess this is what Bill Cook always talks about.

And did I understand you, that the SFL comes very close to the far better Noctivids 😂🤭.

 

[tenex]

The AFOV of the Noctivid is smaller on paper than the AFOV of the SFL, but to my eyes the image feels bigger in the Noctivid.

Does Leica actually publish AFOV? Assuming you meant TFOV, this could be so if SFL 30, despite having less AMD than the 40, still has more than NV. Measurement might confirm this, as well as any possible difference in magnification.

The 3D of the SFL looks more apparent, but I think the smaller DOF and the bokeh create that feel.

DOF should be quite the same; statements like this are difficult to analyze further not knowing exactly what anyone means by "3D", "transparent", etc.

The biggest difference is that the DOF in the Noctivid is enormous compared to the SFL. This gives a very transparant view. Following birds on the wing is much easier. The SFL needs more focusing.

Often confusion over DOF involves field curvature, but in this case I'm reminded of a recent conversation with ReinerBos who found that a slower focuser gave him this impression. Perhaps that's true of SFL vs NV also?

The Noctivid is much sharper, specally at far distance.

Possibly what you mean is that a difference in sharpness is more noticeable with distant targets? That's how it usually is for me.

 

[dalat]

I took the plunge and bought the SFL 8x30. So far only balcony testing, but looks very good. Could replace my 8x42 Ultravid as my main bin. I'll know it after the summer holidays. But in any case, looks like a great bin for 1000 CHF (benefiting from the trade-in action).