An interesting but may not be fair comparison... (1 Viewer)

What would you think a "Leica 7x42 HD" compared with the new "Zeiss Victory HT 8x42"?

(The power is 7x vs 8X)
The exit pupil is 6mm vs 5.2mm;
The field of view is 140m vs 136m in 1,000m;
The weight is 770g vs 785g
The size in length is 141mm vs 160mm


1. Do you think the "increased" brightness of the HT could compensate the loss of 0.8mm in exit pupil size? (in low light usage)

2. How much could it be detected with the 4m/1,000m FOV for the HT?

Would you think it is worthy to sell a 7x42HD and replace with a 8x42HT? (only full size bino)

spiralcoil said:

What would you think a "Leica 7x42 HD" compared with the new "Zeiss Victory HT 8x42"?

(The power is 7x vs 8X)
The exit pupil is 6mm vs 5.2mm;
The field of view is 140m vs 136m in 1,000m;
The weight is 770g vs 785g
The size in length is 141mm vs 160mm


1. Do you think the "increased" brightness of the HT could compensate the loss of 0.8mm in exit pupil size? (in low light usage)

2. How much could it be detected with the 4m/1,000m FOV for the HT?

Would you think it is worthy to sell a 7x42HD and replace with a 8x42HT? (only full size bino)

Click to expand...

These are both very good binoculars, and from your specs. are very
comparable. Since the Zeiss is not out yet, any differences are subject
to your comparison.
If low light is important, I would think the larger exit pupil of the Leica would have an advantage, even over the smaller Zeiss.

Don't be in a hurry to sell the Leica. Test the Zeiss, and see how they
compare. I am thinking you would find them similar in many ways.

Jerry

On a very short try with the pre production Zeiss HT I think it might just set a new standard in performance. Would I prefer it to an alpha 7x42? I'm not convinced. Personally I think I might trade the Leica for the EDG 7x42 now, and hope Zeiss produce a 7x42 HT in due course. If not I wouldn't bother. DOF vs. 2-4% brightness. I'd take DOF.

Many would differ.

David

Replacing an excellent apple with a superb orange would make sense only if you prefer oranges. If 7x really fits your style, don't give it up easily. I like 8x better than 7x myself, the 7x picture is just too small for me, but where I go is mostly open country. The DOF of 7x is amazing, and if your birding is close in and fast, stick with it. Rumor is that 7x42s are going out of style because of poor sales, and will not be offered in the latest things.

I worked out some simple math. The FL is probably already 4% brighter than the HD, and the HT will take that to 7%. That will be noticeable in good light when the eye is stopped down smaller than either exit pupil, but arguably, in good light, a Leica is bright enough already. But let the sun get low and your eyes start opening up. A 6mm exit pupil has 31% more area, therefore 31% more light content, than a 5.25mm. 24% low light advantage, 7x42 HD.
Ron

Spiral, as has already been mentioned more than once, these are both fine (though different) "alpha's", and, as far as FOV, or AFOV goes, they are about a wash.

It really depends on what for, and how you use them (ie. in lower light, and close-in rapid use, where the more forgiving eye placement, and greater dof of the 7x shows its main advantages - or, over more varied environs where the greater image size of the 8x is advantageous), and also, the characteristics of your own eyesight (visual acuity, distortion characteristics, age related pupil dilation ability, etc).

In terms of raw numbers, both the 7x, and the 8x, have the same 42mm objective, and so the same light gathering ability. One has a 6mm EP, and the other a 5.25mm one - so the 7x is spread over a 30.6% greater area (modified by tr%), when your eyes haven't 'stopped this down' under bright conditions.

Albino's rate the Leica 8x42 Ultravid HD as having 88.1% transmission (even though their graph is higher?! I think the 88.1% value refers to the photopic peak) so the 7x should be similar, and Zeiss so far have claimed 95.8% for the HT (even though their half graph released so far, is also higher! at the photopic peak), so multiplying those out, the Leica 7x is proportional to ~24.91mm², and the Zeiss 8x proportional to ~20.74mm². So at most there is only a 20% brightness advantage to the 7x Leica (probably slightly less once we see the rest of the Zeiss tr% curve), but, only when your pupil has dilated to 6mm.

The 7x Leica won't equal, or surpass, the 8x Zeiss for brightness until your eyes have dilated past about 5.5mm diameter. When this happens will depend upon your eyes, and viewing situation. I would think (unless in deep cover) that this would happen sometime about, or just after after sunset, depending on weather conditions (cloud cover etc). The characteristics of your eyes are then going to play a major part in how beneficial this extra EP will be.

Then there is the whole debate around mesopic and scotopic vision, and the Twilight Factor, which would kick in around about this time - and which is more beneficial in the practical sense for binocular viewing - extra objective size (and hence EP for a given mag), or magnification ratio. There seems to be some sort of feeling that once you have at least ~5-5.5mm EP or so, that the magnification starts to take on more importance for seeing detail. (I'm sure there is still much division among the schools of thought though!)

In normal daytime viewing, the Zeiss HT will have about a 9% greater transmission advantage which should be readily apparent (it's felt around here that a 3 - 6% difference is detectable by the human eye). This advantage to the Zeiss may increase a little bit as you transition from photopic to mesopic vision (but still under that 5.25~5.5mm pupil diameter) - we won't really know for sure until Zeiss reveals the 'secret' other half of the transmission curve.

So on one hand you'll have in the order of about a ~10% transmission advantage for the Zeiss during the day, and the resolution advantages of 8x over 7x, versus, the up to < 20% brightness advantage of the 7x Leica after sunset (but only once your pupils expand past 5.5mm), the greater dof, and more rapid eye placement (also affected just as much by ergonomics).

You really will have to try them for yourself, and also see if the 'fit' and 'feel', and colour rendition, of either, overrides the transmission / resolution /dof characteristics of one or the other. Let us know your findings!


Chosun :gh:

do people also consider the design size too...?

Thank you for those very informative and helpful replies!:t:

Also in another note, do people not also to consider the overall size of the binoculars ?

In an occasion I had the 7x42HD next to a 8x42FL (and a 8.5x42EL too), the Leica looked like a clothes with a size smaller, and hence much more elegance, as well easier to carry and store (particularly if with luggage...) , although they are all 42mm.

Yes. The Leica 7 x 42 Ultravid (which I don't have) is smaller and lighter than the Swarovski SLC 7 x 42 which I have. This is true even of the earlier, heavier Leica 7 x 42 Trinovid BN which I do have. I like using the SLC better because of it's longer eye relief and better, IMO, eye cups. But if I were going on a long sea voyage where I needed a 7 x 42 or spending a year in the jungle, I would take the Leica over the Swarovski because it is more compact.

Bob

I'm betting the Zeiss is brighter. Leica is among the dimmest of the big 4. I always figured they traded in brightness for a certain image warmth and contrast and that that process costs them in light throughput.

I have a pair of Leica 7x42 and Zeiss 10x40 classic The zeiss edges put the Leica at night. It seems to me there is something to the twilight factor. (square root of power x objective). If all things were the same the 8x42 HT would have the edge. chip

For me, when I looked through leica HD, 8x42 and 10x50 I wasn't really impressed. I preferred zeiss FL much more. I don't know why, just felt right in the hands and so on. The image felt very dim when looking through the leica, but when looking with Fls the world was bright.
I can only imagine that HTs can be only better than FLs.

I tried out the 7x Ultra at the Bird Fair as well as the 8x HT and I now have the latter at home.

I'm afraid Ron is absolutely right when he referred to apples and oranges: these are different beasts.

The 7x Ultra has that magical quality that 7x's have of bringing you a breathtaking sweep of FOV and depth of field and all without so much as a wobble.

The HTs are ...................... well I have already described the 8x elsewhere so I won't repeat here. They are a worthy successor to the FL and I think will appeal to a wider audience than FL did.

Lee