Larger light grabbing binos wanted.

[Guest]

It is being able to relax in a recliner chair on summer nights with hand held binoculars that is the joy.Thus looking at something like a good set of 10 x 50 might give an improved brighter view than the 8 x 42's.

[Charic]

The 8x42 should give a brighter view due to the larger exit pupil 10x50=5mm  8x42=5.25mm. but only slightly. The 10x50 should have slightly better contrast between the darker sky, due to the higher magnification. 

Really, nothing is straight forward or simple in the game?

[michael.h.f.wilkinson]

The 8x42 should give a brighter view due to the larger exit pupil 10x50=5mm  8x42=5.25mm. but only slightly. The 10x50 should have slightly better contrast between the darker sky, due to the higher magnification. 

Really, nothing is straight forward or simple in the game?

No, nothing is simple, as much depends on the quality of the optics, coating, internal baffles, etc

[trynda1701]

A question about the 10x50 vs 8x42 bins. Although the 8x42 has a slightly wider exit pupil, shouldn't the 10x50, if steadily held or mounted, show more as it is reaching a fainter stellar magitude? Or am I missing something obvious?

Mark

[Charic]

trynda1701.........Hi, You would think so. If you add more magnification, you'd expect to see more, however If you take the same brand binocular in sizes 8x and 10x, as you increase magnification, the field of view is reduced, so visibly the 10x is now showing less, unless the eye-lenses are so  designed to give extra wide angle views. So the 8x42s should have the advantage in regards to brighter, wider and hopefully steadier image. Whereas the 10x50 will get you closer to the target but with less brightness, and with a narrower visual image. In general, the lower the magnification, the brighter the image will be, and higher magnifications reduce the field of view. Contrast between the darker sky and your target may appear to be enhanced as you increase magnification. I've also noted that all binoculars benefit from being rock steady in their use, but not all binoculars have mounting points. The use of both eyes when using binoculars is also an advantage when viewing over using a telescope with a standard single ocular. Although this is basic fact, its not always considered.

As Michael.h.f.wilkinson points out, the quality is also an important issue, and so are the seeing conditions. I have made several recommendation over how good I thought my 7x50s were/are but the newer Helios 8/40s leave them standing. Build quality, exit pupil size ect.

[trynda1701]

charic

I understand about the narrower field of view (luckily I own CZJ Jenoptem 10x50W's! ) and differing contrast, but surely the 50mm should theoretically show fainter stars than the 40mm? Or would the 50mm have to have only 8x magnification to gain that advantage? (I feel I'm being dense somewhere along this conversation! )

Mark

[Charic]

trynda1701..........The larger objective gathers more light, and the bigger the objective, the fainter the Stars you should be able to see. Stars are just points of light and cannot be magnified? but the objective's size and the sky conditions will allow you to magnify the Planets and various other extended objects.

If you take your Jenoptics and divide the aperture into the magnification the result is 5mm of exit pupil, this is the width of the image that appears to float over the eye-lens when held at arms length. Extended image brightness is proportional to the square of the exit pupil. The greater the relative brightness, the brighter the image should be.

So your Jenoptics are  10x50s. 50/10= 5 x5 =25.  The 25 now referring to the relative image brightness ( RB )

Now take the jenoptic 8x50 (If they have one?) 50/8= 6.25 x5.25 = 39.06 image brightness. 

The 8x50 has the higher relative image brightness of 39.06 therefore should have the brightest image result.

As we compared 8x42s, they have a relative image  of 27.56, so yes, the  10x50 will have the higher RB Number, therefore giving a brighter image over the 8x42 in this case, but whether our eyes can actually perceive this is another matter. but on paper, it may be the deal breaker if your dealing with specifications.

......Only the atmosphere is dense? All these questions and answers make for a better understanding on the subject.

[Guest]

I have just bought a set of Helios Stellar 15 x 70 from Ebay.Hope that they are good.

[Guest]

I have just received my Helios Stellar 15 x 70 binoculars.They are discontinued.Very clear views of the night sky last night.I could easily see the double cluster in Persus and The Andromeda galaxy.I would recommend if seen in the good used ads.

[keithatrochdale]

If you guys are ever in the area, give us an e-mail and we will try and give you a look through our 12" binos.

[trynda1701]

If you guys are ever in the area, give us an e-mail and we will try and give you a look through our 12" binos.

You can't just make a statement like that and not show a photograph! Pictures if you please, my good man!

Mark

[Guest]

I have pointed my binos towards Rochdale,by golly I think that I can see them those pesky 12 inchers. :bino2: :bino2:

P.S. As you can see,I've just discovered these icon faces.