Zeiss SFL 8x40 vs 8x30

[JoeK]

Can anyone who has compared these side by side advise on this?
8x30 @ 16oz 8x40 @ 22oz
I’ve heard regarding similar comparison of swaros NL/EL options that weight concious folks maybe happy with the smaller objective and only be giving up on performance right at the first/last minutes of light and the smaller objectives are toe to toe the rest of the day.
But are we talking the last 5-10min or 30-45min?
Specs list 6ft greater FOV on the 30mm which is negligible.
These will be for chest binos on archery hunts and paired with a larger tripod bino for extended glassing and picking apart country.
I’m may be willing to take 6ozs of glass into the backcountry for 30 min of low light performance but if the difference is only noticable 5-15min maybe I’d go light on my chest and free up weight for the companion tripod binos and MAYBE even tote a compact spotter…
hopefully some 14x52NL’s will come into my life one day.
Anybody speak to this issue overall or these specific binos?
Thanks!

 

[blkqi]

To put it simply, the 40mm will exceed the performance of the 30mm whenever your pupil dilates larger than 3.75mm.

 

[JoeK]

Certainly. However I’ve never measured my pupils and I don’t have any clue at what light intensity that occurs…

 

[blkqi]

No one will be able to provide an adequate answer to your question. This varies by individual and depends on genetics, age, etc.

 

[gr8fuldoug]

Your timing is perfect as the Zeiss SFL's just went on $300.00 off sale

 

[Fritz D]

Not tried the 40 mm objective SFLs but I have the 8x30 version of same. I love it. I’ll never look at compact binos the same way?
Physics being what it is, I can only imagine the 8x40 will be even better-with everything save the increased mass?

 

[texasbbq]

Your timing is perfect as the Zeiss SFL's just went on $300.00 off sale

This has to be or right at the best deal going in optics today.

 

[Quandary]

I have the 8x40. Worn in a chest harness. They are so light I barely notice them.

 

[JoeK]

I opted for 8x30 figuring at first light I’m likely to have a set of larger binos on a tripod anyways and then I can enjoy the smaller and lighter form factor on my chest until dusk when I may be giving up a little performance. Notwithstanding any replies comparing the two on this thread I may still end up ordering a pair of 8x40 and comparing them side by side myself…

 

[JoeK]

Not tried the 40 mm objective SFLs but I have the 8x30 version of same. I love it. I’ll never look at compact binos the same way?
Physics being what it is, I can only imagine the 8x40 will be even better-with everything save the increased mass?

From what I’ve seen on optics comparisons and heard on a couple of podcasts the two may be nearly identical in optical performance until, as blkqi stated, your pupil dilates beyond the 3.75 exit pupil of the 30mm. But smaller and lighter in the hand has a real advantage with a bow in one hand.

 

[JoeK]

I compared the 8x32 SFL and 8x40 SFL and for very little size/weight penalty I found the 40's to be all around brighter and easier to glass with. I have not had a chance to look through the NL 32's but I am sure they are great glass and would serve you well especially for archery season.

^from the 10x32 NL thread which is addressing the same basic points of 30/32mm vs 40/42mm binos though with a distinct context for the other OP.

Really gonna be hard now not to just get my hands on the 8x40s and run my own side by side comparison.