Telescope Reviews: Few 50mm Binoculars handheld vs mounted

Here's a few comparative notes out of some recent observations. Here you can compare, first the difference in what a binocular can see handheld vs mounted and second, some differences between 7x50 and 10x50. Finally you can see a difference between the two 10x50s.

50mm Binoculars, Leopold 10x, Fujinon 10x, Captain’s 7x,
Shown for each model is nominal stated size - stated fov, actual effective aperture, actual Tfov, actual er, close focus ft., fov at close focus.

Fujinon FMT-SX 10x50 - 6.5°, 10x49, 6.7°, er=13mm, 50ft, 6.4°
Leupold Wind River Mesa 10x50 - 5.5°, 10x49, 5.3°, er=17mm, 23ft, 5.1°
Captain’s Helmsman 7x50 - 7.2°, 7x46, 7.3°, er=17mm, 30ft, 7.2°

Referred here as F10, L10, H7

H7 handheld see only the two eyes of the Owl cluster NGC457. Occasionally see a faint glow for the remainder of the wings, body and feet.
L10 handheld sees the two eyes and 2 or 3 more stars resolved and the glow of the remaining stars is constant.
F10 handheld sees the two eyes plus 4 stars resolved and the unresolved glow.

The Double Cluster, preceeding cluster and following cluster,
H7 handheld sees 5 stars pre, 6 stars fol
H7 mounted sees 9 stars pre, 13 stars fol
L10 handheld sees 8 stars pre, 8 stars fol
L10 mounted see 10 stars pre, 13 stars fol
F10 handheld sees 8 stars pre, 11 stars fol
F10 mounted sees 12 stars pre, 21 stars fol

For reference
Fujinon 16x70 mounted sees 32 stars pre, 37 stars fol
Megrez80 at 13x80 mounted sees 28 stars pre, 34 stars fol

I recorded several observations of Comet Holmes with the L10x50 and F10x50 (both on loan from the most generous Walter Locke) and the H7x50. I used the smaller 10x and 7x binoculars both mounted and handheld. In the H7x50 it was difficult to see the differentiation of the bright central core and the wider coma, especially handheld. It appeared mostly as a bright diffuse extended object, but at times I could make out the brighter core. In both 10x50s, for moments I could hold them still enough to notice a distinction between the brighter center and the fainter coma. The nucleus was not seen in any of these 50mm binoculars, even when mounted.

The H7x50 provided a very nice wide-field view that included the entire Alpha Perseus Association in the same view with comet Holmes, a pleasant escape from the views I made for detailed measurements. The L10x50 just barely covered this area, but the H7x50 did so with room to spare.

The Helmsnan 7x50 has the widest fov and did provide some of the nicest wide field views. For instance, Comet Holmes was observed in same fov with the Perseus moving cluster. The Double Cluster was observed with the running man Stock 2 cluster in context. However, the Fujinon 10x50 is very close in fov and provided nearly the same wide field experience, and with much more detailed information. The Leupold is quite narrow and would not provide these wide-field views. And although the 7x50 does provide the widest fov, in every instance, handheld or mounted, it provided the least amount of detailed information.

Summary:
Both 7x50s and 10x50s view improves when you go from handheld to mounted.
10x50s allow seeing considerably more than 7x50s, both handheld and mounted.
Claims that you can see more handheld with a 7x50 than with a 10x50 because of lower magnification showing less shake don't seem to hold much weight when supported with measurements of what can actully be seen.

edz

edz

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