Zeiss Conquest HD 8x32 vs. 8x42 for birding (2 Viewers)

[sope0018]

I recently bought a pair of Zeiss Conquest HDs in the 8x32 format. For me, this is a near-perfect binocular. It has a large FOV at 420 ft and a large AFOV at 64 degrees which provides a very immersive image. It handles well, focuses quickly and smoothly, feels great in the hand, is built like a tank, accommodates my rather narrow IPD, eye relief is perfect for me (I do not wear glasses), it focuses nice and close for nearby feeder viewing... I can go on! It is a very well-balanced instrument. However, one evening I was out birding in a forested marshy area following a storm. I was tracking a nighthawk and a few other birds by sound. It was about 1 hour before sunset. Conditions were fairly dim under the forest canopy. I scanned up into the tree tops and could make out some detail, but not well enough to discern tree bark from a stationary bird. I am young and have good vision. I think I may have run into the low-light performance limitation of the 32mm lens + 4mm exit pupil, despite the high-transmission glass found in this bino. I go birding at all hours of the day, including after work and well into twilight. Given the great things I had read on the forum about the CHD 8x32, including some folks mentioning that it could be used in low-light situations better than one might expect, and all the positive things I mentioned above, I really wanted it to work out! I ended up returning it after a few days due to the less than desired low-light performance.

So now, I'd like to try out the CHD in the 8x42 format because the 42mm objectives and 5.25mm exit pupil should let in more light for the conditions I bird in. I haven't been able to test one locally, but I have been able to test it in a store in the 10x42 format. It is also an amazing bino for the same reasons the 8x32 is, and it has an even larger AFOV at 66 degrees. I am reasonably sure that ergonomically, the 8x42 format will work for me, though I may need to get the longer eye cups from Zeiss.

The reason I have not already bought them, however, is because of the model's stated FOV and AFOV. Where the 8x32 and 10x42 have quite large FOV and AFOV (near the top of their class at this price point), the 8x42 has a rather "normal" FOV of 384 ft and AFOV of 59 degrees. My worry is that after experiencing the 8x32, whose FOV is 40 ft wider and AFOV 5 degrees wider, am I going to feel like I'm staring through a tunnel in the 8x42 format? Do other folks on the forum have experience with these specific models who could comment on this? Can folks explain why the 8x32 and 10x42 CHD have such large and immersive AFOV while the 8x42 seems to be more narrow? Does it actually feel narrow? Do the views actually feel quite similar between the 8x32 and 8x42? I'm guessing the 8x42 might be my goldilocks bino but would love to hear about other people's experiences with them. I hope I've not ruined other binocular views after experiencing the 8x32! Thanks for any insights and happy birding!

 

[BKoh]

Order the 8x42 from a retailer that allows returns and see for yourself.

But for low light performance most people suggest a 7mm exit pupil eg 7x50 or 8x56. The obvious penalties are weight and AFOV. But the 7mm exit pupil will let in 3 times as much light (if your pupils dilate to 7mm).

The human eye responds exponentially, not linearly, to light. All things equal, 42mm collects 72% more light than 32mm. But you will not perceive it as 72% brighter. You will see the difference when it is dark, but whether the improvement is enough, only you can decide.

 

[Swedpat]

Sope0018,

I have the 8x42 since several years but consider to replace it with the 8x32, because I recently got a NL Pure 8x42. I recently tried 8x32 and was glad the eye relief was fully sufficient with eyeglasses, maybe the most eyeglasses friendly 8x32 on the market. But it's bulky for being a 8x32. Still noticeably smaller and lighter than the 8x42.
I think the FOV is a matter of being used to. I consider the FOV of 8x42 not being wide but neither narrow.
The difference in brightness between 4 and 5,25mm exit pupil is noticeable in low light but not huge.
I also wonder why the FOV almost always is larger with 8x32 than with 8x42 of same series.
Swarovski EL and NL are an exception.

 

[sillyak]

I would measure your dark adapted pupil. You should be able to Google how to do that. I would start with that before I make a decision.

There is a pretty significant difference in going from a 4mm exit pupil to a 5.25mm, but as others have said, it isn't an absolutely massive difference. You could look at a different binocular model that offers a wider AFOV in a 8x42mm.

 

[chill6x6]

Hmmmm... I've run into this a few times BUT low/poor light is just that. I have never seen a difference comparing 8X32 and 8X42. I talking about carrying both binoculars to the field at the same time. I can see SOME difference with a 10X56...prob not enough difference to ID a bird. There is no reason to not use a 8X32 you like IMO. The Conquest HD 8X32 is a great choice. Now if you just WANT a 8x42, get it. But don't expect any meaningful lowlight performance increase.

 

[Viraj]

I also agree with the @chill6x6. I expected to see a huge difference in the low light performance between M7 8x30 and NL 8x42 but I didn't. I didn't do a Pupil Dilation Test by myself however, I did an overall eye test approximately 5 months ago and had no issues with eyesight. I am in my mid-30s but my pupils might not dilate well because I used to live in a tropical country and usually didn't use eye protection in bright daylight. Surprisingly, I can resolve much more detail in the dusk with Canon 12x36 III with IS enabled.

 

[Swedpat]

I also agree with the @chill6x6. I expected to see a huge difference in the low light performance between M7 8x30 and NL 8x42 but I didn't. I didn't do a Pupil Dilation Test by myself however, I did an overall eye test approximately 5 months ago and had no issues with eyesight. I am in my mid-30s but my pupils might not dilate well because I used to live in a tropical country and usually didn't use eye protection in bright daylight. Surprisingly, I can resolve much more detail in the dusk with Canon 12x36 III with IS enabled.

I am just curious: is there any reason to expect that your dilated pupil size might has been worsened because of bright daylight?
I have not heard about that before.

 

[Viraj]

I am just curious: is there any reason to expect that your dilated pupil size might has been worsened because of bright daylight?
I have not heard about that before.

Actually, I have mistaken. Chronic exposure to sunlight cause several eye problems such as cataracts development, however, I couldn't find any effect on pupil dilation. I am sorry for the wrong point I made.

However, while ago (22:00 hr), I have checked both NL and M7 side by side but couldn't see a noticable difference of brightness. I am wondering why my eyes can't catch it.

 

[Ted Y.]

An 8x42 is preferable when one cannot keep the 8x32 stable enough.
Also, in moments of low light when 8x42 is more effective.
One must test and decide.
Some for FOV difference. It depends on observer.
For me, FOV of 384 ft (at 8x) is no problem.

 

[Ruff-Leg]

Years ago on Better View Desired, Steve Ingraham's now defunct website, he did a side by side test of 8x32 v 8x42 and their ability to yield usable detail in the waning light of descending twilight. As I recall, the difference was about 15 minutes. The article may still be out there (and I may have oversimplified...)

The point is, the benefits of 4mm v 5.25 exit pupils may be smaller than one might think.

 

[sope0018]

This is all great feedback. It sounds like in order for me to pick up any meaningful difference in low light conditions at similar magnification, I would need to try something with a much larger (50mm+) objective lens - and even then it might not be that much of a performance gain. I know I don't want a bino that big. I tend to cover a lot of ground while birding, hiking and such. I enjoyed the relatively compact size of the 32mm objective in the conquest hd, and if I'm not going to get much more low-light performance in such a reasonably sized package, I think I'm willing to accept that compromise in favor of carrying a smaller bino.

 

[Paultricounty]

Seems like maybe your expecting to much from the optics. As others here mentioned going from 4 to 5.25 exit pupal is not really going to give you a night and day difference (no pun intended). Comparing an equal quality 32 mm to a 42 mm really isn’t gonna give you more than another 15 minutes or so of observing time.

Other than exit pupal, light transmission of the optic is another consideration. To gain a few more minutes of observing time you’d have to go with larger exit pupal at cost of weight 8x56 or something with a higher light transmission. My evening choice of optics is a 7x42 Swaro Habicht. To me these are brighter than any 842 or any 7x I have. These do have a tunnel vision but I can read license plates two blocks away with just street lights. 😄

 

[Ries]

As long as you're not specifically birding in twilight conditions, or higher up north in forests, you won't notice much difference and it's mainly ergonomics and optical quality to decide on. For real low light improvement think of 8x50 or 7x42. Here in Dutchieland in somber winter I do choose a 7x42 and certainly notice brghtness difference to Conquest 8x32, especially in the woods.

So when you're not in dark winter areas or targeting twilight viewing like bats, I'm sure a good 8x32 like the Conquest will cover all the needs, and hiking a 8x42 will only be added weight and volume.

 

[sope0018]

That's an interesting thought, Ries. I live in a forested area at about 43 degrees N latitude. It would be interesting to see if latitude, length of twilight, and general weather patterns (it's cloudy a lot here) influenced people's decisions about whether to buy 32mm binos (or smaller) vs. larger objective lenses for added light gathering ability. Out of curiosity, which 7x42 bino do you like to use for winter in Dutchieland?

 

[yarrellii]

I've used the CHD 8x42 for several years and basically got rid of it because of their weight and size. I've also used the CHD 8x32 and I much prefer it overall, but then I don't usually find 8x42 (as a general format) to give me a lot. I didn't get the chance to compare them side by side, but I found the 8x32 to be noticeably bright (overall, I think it's a real gem). But then, my preference could be influenced by the fact that I live in a very sunny place (following Ries train of thought), although I also use my binoculars in trips to places with other light conditions.

As for FOV, I didn't find the 8x42 particularly bad. Yes, on paper the FOV doesn't sound as good as the 8x32, but I don't think that is an actual flaw.
Since you have the 8x32 CHD that is a real allrounder, maybe you could complement it with something with more reach and wider objectives, I had the 10x50 Vortex Viper HD and they were reasonably priced, had very nice optics, a great FOV, build quality seemed nice and were really light and small for a 10x50. That way, you would really have a winning combination: 8x32 and 10x50 when needed.

 

[Ries]

That's an interesting thought, Ries. I live in a forested area at about 43 degrees N latitude. It would be interesting to see if latitude, length of twilight, and general weather patterns (it's cloudy a lot here) influenced people's decisions about whether to buy 32mm binos (or smaller) vs. larger objective lenses for added light gathering ability. Out of curiosity, which 7x42 bino do you like to use for winter in Dutchieland?

I stumbled upon a Meopta Meostar great stuff

 

[james holdsworth]

I’m not sure if there’s any meaningful difference in construction or coatings between the conquest 8x42 and the 32, but I read a lot of comments about quite a bit of CA in the 42s and I see very little in the 32s. And I’m pretty CA sensitive.

 

[Paultricounty]

I tested the 842 CHD and had the 1042 and 832. I thought the 32’s had less CA than both the 42’s. I wound up getting a Genesis 833 (best corrected for CA of any 32 I’ve tried) and the GPO in 1042. Sold both conquest’s. CHD great glass I just preferred the build and construction of the others mentions.

 

[Patudo]

I can't offer an opinion on those specific Conquest models, but I definitely find that if birding in more difficult conditions (poor light, longer distance, etc) I find myself much preferring the 8x42 for its greater ease of view. 8x32s really shine when conditions are good. That said, for true low light observation, to get a real step up in effectiveness you may well need something like a 10x56 (as mentioned by chill6x6). I tried my brother's 10x56 one evening on a peregrine that had gotten into a routine of hunting after sunset and found it quite significantly superior to my regular 10x42. I'm really glad that I don't feel the need to go after nighthawks or other species with similar habits!

re: field of view - like pretty much everyone else I enjoy a wide field of view, but my current 10x42 has a rather narrow field of view and I can live with it. I do notice it after using a wider field binocular, but after half an hour or so I've adapted back to it and everything is fine. If you can position the binocular so that the field stop is as far out as possible (without getting blackouts), even a fairly narrow field of view can seem quite immersive.

 

[Paultricounty]

Interesting point Patudo makes concerning FOV. I noticed the same thing, when using two optically similar quality binoculars. Using one with a very large FOV (like some new premiums) and one with a more general FOV it’s very noticeable going back and forth , but after a while with the smaller FOV, the larger one is not really missed. I seem to settle right into the Image without much thought. Thats not the case when it comes to other attributes , like brightness, edge quality CA correction. Those qualities are very difficult to downgrade as apposed to FOV.

I have a 12x50EL, 7x42UVHD and a Swaro 7x42 Habicht , and had the 10x56SLC and to me the Swaro by far is the brightest and most useful low light bino I’ve ever used. .