Advice: Not too expensive toss in the pocket/bag compact binoculars? (1 Viewer)

[Ignatius]

This factor always seems wird to me...

Careful.
Paddleman peddles half-truths. So does his pal Mr. Whatnot.
There are two measurements that are kinda interesting here: twilight factor (TF) and relative brightness (RB). Only one has to do with the size of the exit pupil (EP) (RB = EP²) while the other, TF, is the square root of magnification x objective aperture.
For his 10x42 vs 8x32 example that gives the following six values: 10x42 - EP=4.2 mm, RB=18, TF=20.5; 8x32 - EP=4 mm, RB=16, TF=16.
This means in daylight both are about equally efficient since the human eye stops down to about a 2 mm pupil. As dusk approaches, the slightly higher relative brightness, which is about discerning details in lower light, and the higher twilight factor, put the 10x42 ahead.

 

[Dennis Mau]

How about the Swarovski, My Junior 7x28? It is the least expensive Swarovski you can buy at $500 with a 4mm EP and has excellent optics, being way brighter and having much easier eye placement than the Curio 7x21 because of the bigger EP. It is not as pocketable as the Curio 7x21 and has a slightly smaller FOV, but you can still throw it in a bag or put it in a coat pocket. To get a 4mm EP with Swarovski glass, you would have to pay over $2000 for an EL 8.5x42 or NL 8x32. It is a bargain even though the colors are a little on the bright side, but that way you don't lose them like the orange Curio!

 

[Maljunulo]

I have always thought twilight factor was nonsense, invented by people who just like to twiddle numbers.

 

[Ignatius]

I have always thought twilight factor was nonsense, invented by people who just like to twiddle numbers.

Had a quick look in my files and found this from a 1958 Zeiss catalog:



Twilight factor has been around for longer than many think. And Zeiss are not really known for frivolous hyperbole.

 

[Dennis Mau]

Careful.
Paddleman peddles half-truths. So does his pal Mr. Whatnot.
There are two measurements that are kinda interesting here: twilight factor (TF) and relative brightness (RB). Only one has to do with the size of the exit pupil (EP) (RB = EP²) while the other, TF, is the square root of magnification x objective aperture.
For his 10x42 vs 8x32 example that gives the following six values: 10x42 - EP=4.2 mm, RB=18, TF=20.5; 8x32 - EP=4 mm, RB=16, TF=16.
This means in daylight both are about equally efficient since the human eye stops down to about a 2 mm pupil. As dusk approaches, the slightly higher relative brightness, which is about discerning details in lower light, and the higher twilight factor, put the 10x42 ahead.

Yes, a 10x42 will kill a 8x32 in low light. That is why hunter's like a 10x42.

 

[tenex]

For his 10x42 vs 8x32 example that gives the following six values: 10x42 - EP=4.2 mm, RB=18, TF=20.5; 8x32 - EP=4 mm, RB=16, TF=16.
This means in daylight both are about equally efficient since the human eye stops down to about a 2 mm pupil. As dusk approaches, the slightly higher relative brightness, which is about discerning details in lower light, and the higher twilight factor, put the 10x42 ahead.

In this example, the 10x42 has the edge in both RB and TF. To tease out the meaning of twilight factor, consider the highest scores among my own bins: which SLC should I use in low light?
10x56 - RB=31.4, TF=23.7
15x56 - RB=13.9, TF=29
I reach for the 10x56 every time. What is TF trying to tell me instead?

 

[tenex]

(What is TF saying instead? It's a question of what you're trying to do, whether it depends on seeing the tiniest details possible, as is not usually the case. See Holger Merlitz, Binocular Handbook, pp.154-155.)

 

[Maljunulo]

Twilight factor has been around for longer than many think. And Zeiss are not really known for frivolous hyperbole.

Thank you.

Certainly not the first time I've been wrong.

I’d still like to know how it’s derived.

 

[Ignatius]

Thank you.

Certainly not the first time I've been wrong.

I’d still like to know how it’s derived.

Ahhh ... I have no idea who came up with that concept/formula in the first place. Of course it could have been Zeiss, it's the sort of thing they'd do. It was in the now retracted DIN 58388 but I no longer have access to those norms and cannot say what exactly it says in there or whether it tells who invented it.
I've dropped a line to Hans T. Seeger about this, but owing to past experience I'm not holding my breath about actually getting an answer.

 

[Jinac]

They are about the same size and weight at 16oz. as most 8x30's like the SFL 8x30, but they will outperform them in low light because of the bigger EP and also have easier eye placement

But the twilight factor ?

 

[Ignatius]

But the twilight factor ?

Not a terribly difficult calculation ...

 

[Jinac]

Not a terribly difficult calculation ...

yes, it was little sarcastic... the TF of the 7x28 is less important that for the 8x30 but...

 

[Binocollector]

DDoptics Lux HR 8x25 is the same bino as the Bynolyt 8x25ED. Found mine for slightly over 200€. It's the perfect "toss in the bag" bino. Optics are really good. They're made in Japan, have a magnesium body, eye cups stay in place once adjusted. And I am not a huge fan of the double hinge on pocket binos. So I prefer the single hinge of the Lux HR. They also have field flattening so at least the whole FoV will be sharp since it's a bit narrow.

 

[Dennis Mau]

DDoptics Lux HR 8x25 is the same bino as the Bynolyt 8x25ED. Found mine for slightly over 200€. It's the perfect "toss in the bag" bino. Optics are really good. They're made in Japan, have a magnesium body, eye cups stay in place once adjusted. And I am not a huge fan of the double hinge on pocket binos. So I prefer the single hinge of the Lux HR. They also have field flattening so at least the whole FoV will be sharp since it's a bit narrow.
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Here is a nice review on the DDoptics Lux HR 8x25. He liked the binocular overall, but he didn't like the focus, which he felt was slow.

"I have owned or used a few pairs of binoculars over the years and cannot remember ever being aware of the focus being fast or slow. I guess they were all pretty similar. The Lux HR 8x25 however are noticeably slow to such an extent that I initially thought they would have to go back. From close focus to infinity is about 2 full turns, my Opticron Travelers are about 2/3 of a turn (which is possibly a bit too fast) The focus does go 3 full turns, but the last turn does not do much – unless possibly if you are viewing stars."

DD Optice Lux HR 8x25 - A quick review

I want to post up a quick review of the DD Optics Lux HR 8x25 that I bought recently. I don’t do reviews as a rule but this is a bit of a Marmite binocular and I feel it would be useful for prospective buyers to know its quirks before ordering. The DD Optics Lux HR 8x25 appears identical to the...

www.birdforum.net

 

[mekidear]

Here is a nice review on the DDoptics Lux HR 8x25. He liked the binocular overall, but he didn't like the focus, which he felt was slow.

"I have owned or used a few pairs of binoculars over the years and cannot remember ever being aware of the focus being fast or slow. I guess they were all pretty similar. The Lux HR 8x25 however are noticeably slow to such an extent that I initially thought they would have to go back. From close focus to infinity is about 2 full turns, my Opticron Travelers are about 2/3 of a turn (which is possibly a bit too fast) The focus does go 3 full turns, but the last turn does not do much – unless possibly if you are viewing stars."

DD Optice Lux HR 8x25 - A quick review

I want to post up a quick review of the DD Optics Lux HR 8x25 that I bought recently. I don’t do reviews as a rule but this is a bit of a Marmite binocular and I feel it would be useful for prospective buyers to know its quirks before ordering. The DD Optics Lux HR 8x25 appears identical to the...

www.birdforum.net

That was me These do have a slow focus, but at middle to far distances where I am predominantly using them, this is an advantage. Much nearer than 10m away, the slow focus and narrow field makes picking up moving birds tricky. This is my most carried and used binocular at the moment though I do only have 3. If you want single hinge, it would be difficult to find better at this price.

 

[Dennis Mau]

That was me These do have a slow focus, but at middle to far distances where I am predominantly using them, this is an advantage. Much nearer than 10m away, the slow focus and narrow field makes picking up moving birds tricky. This is my most carried and used binocular at the moment though I do only have 3. If you want single hinge, it would be difficult to find better at this price.

Outside of the slightly narrow FOV, these look nice, and there are not a lot of single hinge 8x25's at this price point. Single hinge binoculars are a lot easier to use than double hinge, IMO. Dielectric prisms, ED glass. metal eye cups, waterproof and a magnesium body for less than $250. That is a good deal. They are not available in the USA, but you can get them from Teleskop Service, which is a good dealer in Germany. I might have to try these. Thanks for the tip Binocollector and mekidear.

Teleskop-Express: DDoptics Binoculars LUX-HR Pocket ED 8x25-440150010

Pocket binoculars with high quality optical components

www.teleskop-express.de

 

[Dennis Mau]

That was me These do have a slow focus, but at middle to far distances where I am predominantly using them, this is an advantage. Much nearer than 10m away, the slow focus and narrow field makes picking up moving birds tricky. This is my most carried and used binocular at the moment though I do only have 3. If you want single hinge, it would be difficult to find better at this price.

How is the eye relief compared to the eye cup length? Are the eye cups long enough for the eye relief, or do you have to float them?

 

[mekidear]

I use these without specs and with the eye cups all the way out, I have no issues with eye relief.

I will add that I have never had eye relief issues on any binocular so I might just have an accommodating face. (I am sure there is a joke in there somewhere)

 

[Dennis Mau]

I use these without specs and with the eye cups all the way out, I have no issues with eye relief.

I will add that I have never had eye relief issues on any binocular so I might just have an accommodating face. (I am sure there is a joke in there somewhere)

Exactly! Thanks! I have shallow eye sockets, so I have problems if the eye cups aren't long enough for the eye relief. The Zeiss Victory 8x25 is a good example of a binocular that has eyecups that are too short for the eye relief for me which means I either have to float it or I get blackouts.

 

[forent]

DDoptics Lux HR 8x25 is the same bino as the Bynolyt 8x25ED. Found mine for slightly over 200€. It's the perfect "toss in the bag" bino. Optics are really good. They're made in Japan, have a magnesium body, eye cups stay in place once adjusted. And I am not a huge fan of the double hinge on pocket binos. So I prefer the single hinge of the Lux HR. They also have field flattening so at least the whole FoV will be sharp since it's a bit narrow.

These DDoptics Lux HR 25's are quite amazing! Some months ago I replaced my Leica Trinovid 10x25 BCA with the Zeiss Victory Pocket 10x25 and could not be happier.

However, a test report by Gijs van Ginkel on the 8x25 (https://www.houseofoutdoor.com/wp-c...-van-8x25mm.-verrekijkers-5-februari-2019.pdf) drew my attention to the DDoptics Lux HR 10x25, which, in contrast to the 8x25 version, has a fairly wide field of view. The features, warranty conditions and service offered by DDoptics were also impressive. I ordered one and was really impressed. Without exaggeration: if I wasn't so extremely satisfied with my Victory Pocket 10x25, I would have kept the DDoptics. Its wide field of view, the single hinge, the large focuser and the comfortable eyecups (no blackouts) make it very pleasant to use. The optical performance is excellent, even if its contrast is slightly weaker than in the Zeiss. In addition, the focuser is a little too slow for me (as with e.g. most Swarovski binos). But that's nitpicking. Hence, I recommended the DDoptics to a mate who was looking for a lightweight bino for birding on his long hikes. He bought it and is very happy with it.

The DDoptics Lux HR 10x25 is a real bargain IMHO. Highly recommended!