Curio 7x21 vs. CL 8x25 pocket (1 Viewer)

[Trinovid]

...you would be wise to also consider the excellent Zeiss Victory Pocket 8x25 which for me in a recent comparison was better optically than the Swaro CL 8x30 when I was expecting the opposite to be the case.

The Victory Pocket is already legendary, and for very good reasons, but if you're doing a comparison against a compact Swarovski, it'd be a little more fair to make the comparison against their finest tiny performer, the Curio.

I already own the Curio, but will also have the Victory Pocket someday as well.

 

[NatureLvrCanada]

Personally I would recommend the Curio between the two. The quality of the image of either is typical SW - excellent. The Curio has the same EP for practical purposes but with much larger FoV, steadier brighter image, greater DoF, meaningfully smaller and lighter and the double hinge is less fiddly for me than with the CL. You won't lose a lot with 7 as opposed to 8x unless you will be doing a fair amount of longer distance viewing with them. YMMV.

Mike

I have the CL Pocket but am looking to get the Curio for the wider FOV. The wider FOV makes scanning an area faster. If I had to do it again, I would have chosen the Curio over the CL pocket for the wider FOV. I had this insight when I used the Vortex 8 x 42 and saw how much easier it is to scan with a wider FOV.

 

[Swedpat]

I have tried both 7x21 and 8x25, but not compared them side by side.
Both provide fully sufficient eye relief with eyeglasses for me.
The 7x21 is significantly smaller and lighter which can actually be a deciding factor in whether you bring the binoculars with you or not, if the 7x21 fits in your pocket and the 8x25 is just a bit too big. AND: isn't the main reason for compact binoculars that they will fit in a small pocket?
The downside of the smaller size is that it is less comfortable in the hands. But all compact binoculars are still too small for a comfortable grip.
In my opinion the CL 8x25 has a nicer design and I prefer the rubberized finish to the slippery 7x21. But you can easily stick some friction tape on the 7x21, and with the black option, black tape won't hurt the design I think.
Therefore I think I will go for 7x21. It is almost as bright as the 8x25 and significantly brighter than the 8x20. And 7x gives less shaky image and wider FOV.

 

[[email protected]]

I have tried both 7x21 and 8x25, but not compared them side by side.
Both provide fully sufficient eye relief with eyeglasses for me.
The 7x21 is significantly smaller and lighter which can actually be a deciding factor in whether you bring the binoculars with you or not, if the 7x21 fits in your pocket and the 8x25 is just a bit too big. AND: isn't the main reason for compact binoculars that they will fit in a small pocket?
The downside of the smaller size is that it is less comfortable in the hands. But all compact binoculars are still too small for a comfortable grip.
In my opinion the CL 8x25 has a nicer design and I prefer the rubberized finish to the slippery 7x21. But you can easily stick some friction tape on the 7x21, and with the black option, black tape won't hurt the design I think.
Therefore I think I will go for 7x21. It is almost as bright as the 8x25 and significantly brighter than the 8x20. And 7x gives less shaky image and wider FOV.

Try a 10x25 pocket. They are a lot better in low light than a 7x21, 8x20 or 8x25. Miserable low light performance is a downfall of pockets, but the 10x25 because of its superior Twilight Factor of 16.0 performs significantly better at dawn and sunset. You can see much more detail.

 

[gweller]

Try a 10x25 pocket. They are a lot better in low light than a 7x21, 8x20 or 8x25. Miserable low light performance is a downfall of pockets, but the 10x25 because of its superior Twilight Factor of 16.0 performs significantly better at dawn and sunset. You can see much more detail.

I thought we had the same discussion a while back and claim to the conclusion that this was pretty much nonsense??

 

[tenex]

How many people buy a pocket bin for use at dawn and sunset?

 

[[email protected]]

I thought we had the same discussion a while back and claim to the conclusion that this was pretty much nonsense??

It is not nonsense. I have compared many 7x21, 8x20, 8x25 and 10x25 pocket binoculars in low light and the 10x25 always wins. The 10x25 is much better in low light than the 8x25 because of the superior Twilight Factor. The higher magnification helps you see detail better, especially in low light. The 10x25 without a doubt outperforms the 8x25.

Sometime compare a 8x25 to a 10x25 in low light. Or try looking at something in low light with just your eyes from say 50 yards away and then move 20% closer or to 40 feet and see how much more detail you can see. That is what higher magnification does for you in low light.

The extra .5 mm of exit pupil in the 8x25 is not enough additional apparent brightness to overcome the extra 2x magnification of the 10x25. You may not buy a pocket binocular for low light, but it might be the only binocular you have with you when the sun starts going down, and you will appreciate the better low light performance.

 

[Swedpat]

Try a 10x25 pocket. They are a lot better in low light than a 7x21, 8x20 or 8x25. Miserable low light performance is a downfall of pockets, but the 10x25 because of its superior Twilight Factor of 16.0 performs significantly better at dawn and sunset. You can see much more detail.

Here we go again...
First of all: I personally consider 10x as too high magnification for a pocket just because of the difficulty to hold it steady.
10x25 has exit pupil of 2,5mm, and therefore exactly the same image brightness as a 8x20, ~30% dimmer than 7x21 and 36% dimmer than 8x25. And yes: unless it's not too dim you can still see more details than 8x20, 7x21 and 8x25. But when it is enough dark and the image in 8x20 and 10x25 reveal no details at all, some details can still be seen in 7x21 and 8x25.
Difference is very subtle though and it is an exegerration to say that 10x25 performs significantly better. Higher magnification always reveal more details providing the brightness is enough to reveal details.
The actual difference can be described as following naked eye views when standing at different distances:

8x20: 12,5m watching through 2,5mm hole
7x21: 14m through 3mm hole
8x25: 12,5m through 3,125mm hole
10x25: 10m through 2,5mm hole

Twilight factor is not a scientific formula like relative brightness index and it's wrong to claim that low light performance is better because of higher twilight factor.
And this I have explained earlier.

 

[[email protected]]

Here we go again...
First of all: I personally consider 10x as too high magnification for a pocket just because of the difficulty to hold it steady.
10x25 has exit pupil of 2,5mm, and therefore exactly the same image brightness as a 8x20, ~30% dimmer than 7x21 and 36% dimmer than 8x25. And yes: unless it's not too dim you can still see more details than 8x20, 7x21 and 8x25. But when it is enough dark and the image in 8x20 and 10x25 reveal no details at all, some details can still be seen in 7x21 and 8x25.
Difference is very subtle though and it is an exegerration to say that 10x25 performs significantly better. Higher magnification always reveal more details providing the brightness is enough to reveal details.
The actual difference can be described as following naked eye views when standing at different distances:

8x20: 12,5m watching through 2,5mm hole
7x21: 14m through 3mm hole
8x25: 12,5m through 3,125mm hole
10x25: 10m through 2,5mm hole

You will see more detail at 10m through a 2.5mm hole than you will through a 3.125mm hole at 12.5m in low light. Try it sometime. Compare how much detail you can see through a 8x25 versus a 10x25 in low light. Use something like a dollar bill that has a lot of detail on it and try and read it.

In low light, it makes more difference how close you are to an object than a very slight difference in brightness. Look at something in low light with a lot of detail on it with your own eyes from 12.5m and then move 2.5m closer and see how much more detail you can see.

 

[Rg548]

We're talking minutes difference in dawn and dusk light levels between these models.
My FL8x56's were amazing, but my 10x42's were no where near as far behind as the facts and figures would have you believe.
10mins or so of light level difference was all it was give or take.
Too much is put on this brightness... when the light is gone, it's gone.
I sold my 8x56's because the itch wasn't worth the scratch.... a bit of dawn and dusk advantage just wasn't worth it to me.
All different aren't we.

 

[[email protected]]

We're talking minutes difference in dawn and dusk light levels between these models.
My FL8x56's were amazing, but my 10x42's were no where near as far behind as the facts and figures would have you believe.
10mins or so of light level difference was all it was give or take.
Too much is put on this brightness... when the light is gone, it's gone.
I sold my 8x56's because the itch wasn't worth the scratch.... a bit of dawn and dusk advantage just wasn't worth it to me.
All different aren't we.

I have to disagree. My 8x42's and 10x42's gave up when the light started getting low, but my 8x56 just keeps performing even into almost complete darkness.

With the 8x56, it is almost like they have a built-in light inside of them that illuminates the FOV. It is way more than 10 minutes difference. Even when it is almost pitch black out, I can make objects out with the 8x56.

You can see more in low light with an 8x56 than with your own eyes because with 8x magnification you have moved 8x closer to the object. The 8x56's are almost like night vision. Of course, transmission does make a difference. I think the 8x56 SLC with the AK prism has almost 93% transmission

 

[gweller]

I have to disagree. My 8x42's and 10x42's gave up when the light started getting low, but my 8x56 just keeps performing even into almost complete darkness.

With the 8x56, it is almost like they have a built-in light inside of them that illuminates the FOV. It is way more than 10 minutes difference. Even when it is almost pitch black out, I can make objects out with the 8x56.

You can see more in low light with an 8x56 than with your own eyes because with 8x magnification you have moved 8x closer to the object. The 8x56's are almost like night vision. Of course, transmission does make a difference. I think the 8x56 SLC with the AK prism has almost 93% transmission

Isn't this above statement counter to your argument that a 10x25 is better than a 8x25 at dawn/dusk?? Under your premise surely the 10x42 will be better (because of the higher mag.) than the 8x56? Seems to be you just twist things around to suit your own biased opinions...

 

[tenex]

It is known that some older people's pupils still dilate significantly more than others'. This could explain some variation in personal experience regarding the advantage of larger objectives in low light.

 

[[email protected]]

It is known that some older people's pupils still dilate significantly more than others'. This could explain some variation in personal experience regarding the advantage of larger objectives in low light.

Exactly. I am older than dirt, but my SLC 8x56 still seemed brighter than my my Conquest HD 10x56 in low light. I could see more detail with the 10x56, though.

 

[[email protected]]

Isn't this above statement counter to your argument that a 10x25 is better than a 8x25 at dawn/dusk?? Under your premise surely the 10x42 will be better (because of the higher mag.) than the 8x56? Seems to be you just twist things around to suit your own biased opinions...

How so? The Twilight Factor of the 10x25 is 15.8 and the 8x25 is 14.1 so the 10x25 will show more detail in low light. The Twilight Factor of the 10x42 is 20.4 and the 8x56 is 21.1 so the 8x56 will show more detail in low light and because there is a big difference in EP the 8x56 will be much brighter. A 56mm objective pulls in almost 2x the light of a 42mm objective.

 

[Swedpat]

How so? The Twilight Factor of the 10x25 is 15.8 and the 8x25 is 14.1 so the 10x25 will show more detail in low light. The Twilight Factor of the 10x42 is 20.4 and the 8x56 is 21.1 so the 8x56 will show more detail in low light and because there is a big difference in EP the 8x56 will be much brighter. A 56mm objective pulls in almost 2x the light of a 42mm objective.

But a 20x25 has twilight factor of 22,36 so it shows even more detail than 10x25, it's actually as good as 10x50. 25x20 the same. Or why not a 40x25? Twice the twilight factor as 10x25 and better than 10x50.

Not really...

The twilight factor is not an optical law, but only a way to try to describe the fact that magnification can help to show more details despite brightness is lower. TF has its limitation because it's necessary to take both exit pupil and the current light condition in consideration.
Therefore it's wrong to base low light performance on TF alone and use it like it alone determines the low light performance.

 

[Trinovid]

How many people buy a pocket bin for use at dawn and sunset?

How many people buy any binocular for use at dawn and sunset?

I bought my binoculars to use, and when they're not working any more I put them away.

 

[gweller]

But a 20x25 has twilight factor of 22,36 so it shows even more detail than 10x25, it's actually as good as 10x50. 25x20 the same. Or why not a 40x25? Twice the twilight factor as 10x25 and better than 10x50.

Not really...

The twilight factor is not an optical law, but only a way to try to describe the fact that magnification can help to show more details despite brightness is lower. TF has its limitation because it's necessary to take both exit pupil and the current light condition in consideration.
Therefore it's wrong to base low light performance on TF alone and use it like it alone determines the low light performance.

This is why I believe Dennis' premise is too simplistic - there are many more, and more important factors, that makes a binocular suitable for those crepuscular birders amongst us.

 

[[email protected]]

But a 20x25 has twilight factor of 22,36 so it shows even more detail than 10x25, it's actually as good as 10x50. 25x20 the same. Or why not a 40x25? Twice the twilight factor as 10x25 and better than 10x50.

Not really...

The twilight factor is not an optical law, but only a way to try to describe the fact that magnification can help to show more details despite brightness is lower. TF has its limitation because it's necessary to take both exit pupil and the current light condition in consideration.
Therefore it's wrong to base low light performance on TF alone and use it like it alone determines the low light performance.

I know what the Twilight Factor is, and I know it is not an optical law, and using unrealistic binocular formats like a 20x25 or 40x25 to try to disprove it is an old trick that makes no sense because no 20x25 or 40x25 binoculars exists.

There are two things to consider in a binocular in low light, Relative brightness and Twilight Factor. I never base low light performance on Twilight Factor alone. But my point is when relative brightness is close because there is not a huge difference in EP like in a 10x25 and 8x25 binocular Twilight Factor is more important than Relative Brightness.

The additional 2x magnification allows you to see much more detail in low light than the small amount of additional brightness from the slightly larger EP that the 8x25 provides over the 10x25. I have tried many 8x25 and 10x25 pocket binoculars in low light and from experience I know the 10x25 will outperform the 8x25. If you want a pocket binocular, and you think you may use it in low light, a 10x25 is a better choice than an 8x25.

Of course even in the daytime a 10x25 will show you more detail, but the 8x25 will have a bigger FOV and better DOF. Since pocket binoculars are really such poor performers in low light because of their tiny aperture IMO the 10x25 is a better all around choice,

 

[[email protected]]

How many people buy any binocular for use at dawn and sunset?

I bought my binoculars to use, and when they're not working any more I put them away.

A lot of times there are a lot of birds out in the morning and at dusk. I observe a lot of waterfowl and the best time to observe them are dawn and dusk, and sometimes I only have my pocket binocular with me because I carry them when walking my dog around the lake or by the river.

Owl watchers especially use their binoculars a lot at dawn and dusk when Owls are most active, so low light performance is very important. I am not saying the 10x25 is the best tool for low light, just that it is better than an 8x25.