I just wanted to ask those on this forum a question concerning magnification power of two bino's of different power but the same lense diameter and model.

In other words which is going to be clearer and most efficient in low light as well as full sun light. We are speaking of comparing a pair of Pentax 12.5 x 50mm Pentax DCF - SP
to a pair of 10 x 50mm Petax DCF - SP.

I have been told that the 12.5 x 50 will not be as bright in the low light compared to the 10 x 50 bino's. Is this a true fact or somebody's wishful thinking?

In theory, the 10x binos would be brighter in low light than the 12.5x- all other factors being equal.
In real life, you would only be able to discern this in rare conditions of extremely low light, and when your eyes had fully adjusted to low light conditions- in other words, don't worry about any difference in light gathering for most purposes.
Pentax makes very good binos, BTW- very good.
A factor I'd think about, if you're trying to pick which set to buy, is whether you can hold 12.5x steady enough to be usable. No one can hand hold binoculars as steadily as a tripod would. IME, some people can hold 10x glasses steady, some can't (personally, 8x is my limit for holding real steadily).
Holding 12.5x binos steady is something a lot of folks can't do.
You'll get eye fatigue if the image is bouncing around a lot, and it's hard to make out details.
If you typically use a tripod or some other type of rest, maybe not a problem for you.

Jack,...........Thanks for your words of wisdom!

I decided that I would buy both pair and give the 10 x 50 to my wife for watching eagles on the mississippi river near us.

I will keep those 12.5 x 50 for viewing the elk across the canyons, were it is difficult sometimes to see them in the timber. I will use my knees as a brace for my elbows when viewing. I do have a smaller pair of 8 x 42 Bushnell's for viewing off horseback. Thanks once again!

Buy both? Good idea ! :)
Try them side by side and see how they do at dawn and dusk- that's the real proof.
You may find that the 12.5x model has a means of mounting on a tripod- a fairly common feature on glasses over 10x ....

Buy both? Good idea ! :)
Try them side by side and see how they do at dawn and dusk- that's the real proof.
You may find that the 12.5x model has a means of mounting on a tripod- a fairly common feature on glasses over 10x ....

Hello Jack: I finally got those bino's I ordered from a New York company! Now what came to me today where the 12.5 x 50 Pentax.

I quickly took them out of their box to view them against the Bushnell Legends 10 x 42 that I have been using. It was a bit foggy and very overcast with a lot of moisture in the air.

I was viewing a purple martin house 200 yards away for starters with both pair of bino's. I found that right from the start, looking through the Pentax with my glasses on was NOT as simple as viewing through the Bushnell Legends. It seem to be more of a tunnel effect with my glasses on and I could see that I was getting a reflection from my glasses into the eyepiece of the Pentax or for some other reason.

I took my glasses off and compared them that way and soon found out that their is no holding those 12.5 as the salesperson said I should be able to do for several minutes. The Bushnell Legends won out in the test.

Now as far as being "Brighter" I found NO such thing happening comparing both pair of bino's under the NO SUN conditons outside on the back porch. Viewing off 600 yards and more, I saw once again NO visiable difference between the 2 pair of bino's, that my eyes could pick up on.

I would have thought that those 12.5 X 50 would have been brighter, the sales person said "I don't think you will notice a big difference between the 10 x 50 Pentax verses the 12.5 X 50 Pentax. I know I didn't nor my wife notice any difference between those Bushnell Legends that are 10 X 42 and much easyier to hold and put your fingers around them.

The Bushnells and my Leupolds are also easyier to adjust while holding......Ummmm OK, so much for the higher price bino's! I am indeed sending this pair of 12.5 X 50's back and waiting for the 10 x 50 to show up at my doorstep for further evaluation. I hope I can view through those Pentax 10 x 50 with my glasses on as easy as the Bushnells and Leupolds. This pair of Pentax is out of the question, I found them very hard to view through with my glasses on, that is 2 strikes against them from the start.

I am wondering if someone is pulling pulling the wool over the publics eye in these Bino comparisons. Bushnell & Leupolds are so far handier to use, $140 dollars less money. Bushnells and Leupolds weigh less also and I don't see any difference in light what so ever, so why the bigger price on these Japanese Bino's? Their slipover connected, protective eyepieces in the front are a pain in the ARSE too Jack!!!

I really hope those Pentax 10 X 50 work out better, but after viewing these today, I am having my doubts in spades. I'll let you know how they come out in another comparison at my home, as soon as they arrive. I should have listened to YOU instead of the sales pitch I got over the phone from the so called professional and just purchased the 10 x 50 in the first place........Gees! :rolleyes: :o :o

Is there an eyecup that retracts for use with eyeglasses? Most binos have some such provision- the pair I use a lot has rubber eyecups you can roll down if you wear glasses- makes a huge difference. I suspect the 'tunnel effect' is from your eye being too far from the ocular lens- retracting the eyecup should take care of that.
I don't use those objective lens covers. Years ago, I bought a pair of binoculars that had a sliding rubber cover that attached to the neckstrap for the ocular lenses - but no cover for the objective lenses. In practice, when you're carrying the binos around your neck, the objective lenses are towards the ground, and seem to stay remarkably dust free. When you aren't using the binos, they are in a case or on a shelf-probably also standing on their objectives....
Anyway, I was pretty sceptical of the 'no front caps' system, but 30 years of use has converted me.
Thanks for the report.

Is there an eyecup that retracts for use with eyeglasses? Most binos have some such provision- the pair I use a lot has rubber eyecups you can roll down if you wear glasses- makes a huge difference. I suspect the 'tunnel effect' is from your eye being too far from the ocular lens- retracting the eyecup should take care of that.
I don't use those objective lens covers. Years ago, I bought a pair of binoculars that had a sliding rubber cover that attached to the neckstrap for the ocular lenses - but no cover for the objective lenses. In practice, when you're carrying the binos around your neck, the objective lenses are towards the ground, and seem to stay remarkably dust free. When you aren't using the binos, they are in a case or on a shelf-probably also standing on their objectives....
Anyway, I was pretty sceptical of the 'no front caps' system, but 30 years of use has converted me.
Thanks for the report.

Jack, yes they do have eyepieces that screw outward so you can use your glasses when wearing them. I wear mine all the time! However, in comparison to the Bushnells those Pentax have something different about them when I put them up to my glasses to view. They just don't seem to give me the whole picture as the bushnells do.

To me it seems as though the eyepieces are still to close together, even after I try to adjust them and the bushnells are right on period, as though you stuck your head out a window verses looking out that window from across the room. I will just wait for the 10 x 50 to show up and then compare once again.

OK, so even with the eyecups down, the ocular distance is too long for you with your glasses on.
Sounds like the Bushnell Legends are a good fit for you- I dunno if they're a current model or not....
The optimum ocular distance (the ideal distance your eye should be from the ocular lenses) isn't the same for all binoculars. I had a similar problem a number of years ago when I was shopping for binos- couldn't find one that would let me see the full field of view with my glasses on- I wear glasses all the time, too.
I DID find a pair with a bit longer ocular distance that let me see the whole field when I rolled down the eyecups, but you may not like the answer......
They were Leicas :) not cheap, but after using them for 30 years, it works out to a pretty cheap per year price.

OK, so even with the eyecups down, the ocular distance is too long for you with your glasses on.
Sounds like the Bushnell Legends are a good fit for you- I dunno if they're a current model or not....
The optimum ocular distance (the ideal distance your eye should be from the ocular lenses) isn't the same for all binoculars. I had a similar problem a number of years ago when I was shopping for binos- couldn't find one that would let me see the full field of view with my glasses on- I wear glasses all the time, too.
I DID find a pair with a bit longer ocular distance that let me see the whole field when I rolled down the eyecups, but you may not like the answer......
They were Leicas :) not cheap, but after using them for 30 years, it works out to a pretty cheap per year price.

Jack, bottom line is your RIGHT!!! I will never again purchase a pair of Bino's over the internet, unless I can find them and try them out first. Taking the words of comparison tests are NOT THE ROUTE TO GO. I will keep on searching and maybe those Leica's or Swaroskies will find my house sooner than I expected.

2bits, if you can scrape up the money, I doubt you'll be sorry.