Can the geovids rangefinder binoculars be used for solely visual use? (1 Viewer)

[iseegeorgesstar]

Hey,

I recently realized or re-realized that the Leica Geovid rangefinger binos have a special porro prism. "Perger porro". Being the porro addict that I am, I'm wondering how these rangefinger binoculars would work for visual? Is there always some range tracking viewable inside the eyepiece or can it be shut off? I've never used a rangefinder bino or mono so don't know how they work. (Though I've entertained the idea of picking up the maven's rangefinder monocular in the past.)

Thanks for your comments on the geovid.

 

[John A Roberts]

Hi iseegeorgesstar,

Yes they can. There’s an on/ off switch for the electronics (#2):



- - - -
The use of Perger prisms in the 3rd generation Geovids results in a distinctive shape, along with a degree of offset to the optical axes
(14 mm on the x42 version at an unspecified IPD setting):


Image of Perger prism from Holger Merlitz.



For some examples of the axial offset of various models of roof prism and Porro prism binoculars see post #26 at: Premium (Alpha) vs Image stabilized


And for more on Perger prisms see: Perger Prisms

- - - -
Most premium RF binoculars bring a lot of baggage compared to the non-RF alternatives (especially if you don’t intend to use the RF functions).

Besides significantly greater cost, they're also typically larger and heavier.
Leica Geovid x42 (33.4 oz/ 950 g) verses Geovid Pro x32 and BA x42:


Cropped and lightened image from Josh Boyd at: Leica Geovid Pro 32 Review - Rokslide

For a lot more comparative images see posts #241 and 251 at: 6 January 2022 - New Leica announcement


And the implementation of the RF functions in binoculars often results in: a considerable loss in overall transmission;
significant differences in the transmission of the two barrels, and; some very strangely shaped transmission curves!
See the graphs from various tests conducted by Gijs at: Loss Of Brightness With 8X42 RF (HT)


John

 

[iseegeorgesstar]

I really appreciate the links. Thank you very much for a very informative post.

It seems, like Alice, I've found another rabbit hole to fall into

I wasn't aware of the loss of brightness factor. The 42mm at 33oz basically have the weight of a 50mm I think. I'm curious how pronounced the 3D effect is in these compared to more traditional porros like the SW Habicht.

 

[John A Roberts]

Hi again iseegeorgesstar,

A Perger Geovid x42 has only around 1/4 the objective offset of the Habicht Porro series (14 mm vs 57 mm),
so probably not a significant effect, even at close distances:

To give an idea of the amounts of objective offset possible for different prisms and binocular types:

A) John/ Tringa 45 has previously provided measurements for the following roof prism models,
in post #6 at: [Tech] Are most/all roof binocular oculars and objectives collinear?
Using an IPD setting of 63 mm:
Swarovski SLC 7x42, 2 mm
Swarovski EL SV 10x42, 5 mm
Meopta B1 7x42, 6 mm

Swarovski SLC 8x56, 15 mm (Abbe-Koenig prism)


B) From Leica (IPD unstated):
Geovid Rangefinder x42, 14mm (Perger prism)


C) And from me, using an IPD setting of 63 mm:
Swarovski EL SV 12x50, 9 mm

And some Porros:
Swarovski Habicht 10x40, 57 mm (also Habicht 8x30)
Nikon E 12x40, 63 mm (also E 8x30)
Nikon E II 10x35, 63 mm (also EII 8x30)

- -
So hopefully someone with a Canon 10x42 can provide a measurement for comparison.

- - - -
As can be seen, there's significant differences between:
• what's possible in moderate sized Schmidt-Pechan prism binoculars (2 to 6 mm);
• larger Abe-Koenig prism binoculars (at least 15 mm), and;
• regular configuration Porro prism binoculars (60 mm +/-).

And while some may be able to appreciate the relatively minor effects of 2 to 6 mm of offset, or more likely 15 mm,
either is likely to seem minimal compared to conventional Porro binoculars.
(Personally, I'm never aware of the mildly enhanced effect of my EL 12x50, whereas the effect of the Porros
is always immediately perceptible at closer distances).

. . .

John

 

[Canip]

I'm wondering how these rangefinger binoculars would work for visual?

Actually - very very well !
John posted lots of useful info (as always!) already, so I can make it brief: the Geovid is one of my most used 8x42 binos for visual observations. The built-in rangefinder is in my experience not as powerful as expected, see Leica Geovid 8×42 HD-R (Typ 402) – Binoculars Today
But for visual, I find the Geovid right up there with the best.

 

[Gijs van Ginkel]

We have investigated among others the Leica Geovid Pro 8x32 and the GPO Rangeguide 8x32 . Both are very well suited for use as a standard binocular and especially te GPO Rangeguide has a very good handling comfort as a standard binocular since the tubes are less bulky as the tubes of the Leica (a test of both binoculars is published on the WEB-site of House of Outdoor).
Users/hunters who are color blind can not use any rangefinder binocular as a rangefinder, since the red colored measured values can not be observed with their color blind eyes (personal communication from Jan van Daalen from House of Outdoor).
Gijs van Ginkel

 

[iseegeorgesstar]

Hi again iseegeorgesstar,

A Perger Geovid x42 has only around 1/4 the objective offset of the Habicht Porro series (14 mm vs 57 mm),
so probably not a significant effect, even at close distances:




John

I see what you're saying now. That is a big difference between the two. I could definitely see the 3D effect upclose on trees with the Habicht. The various branches at different lengths from each other create a 3D dimensional space.

On a side note, is there a table somewhere that shows the various objective offset's of some of the more used porro binoculars?

"The use of Perger prisms in the 3rd generation Geovids results in a distinctive shape, along with a degree of offset to the optical axes
(14 mm on the x42 version at an unspecified IPD setting): "

I think I wrongly assumed that the "optical axes" might have to do with CA and how and which colors are presented at different lengths. Thank you for deepening the hobby for me.

 

[iseegeorgesstar]

Actually - very very well !
John posted lots of useful info (as always!) already, so I can make it brief: the Geovid is one of my most used 8x42 binos for visual observations. The built-in rangefinder is in my experience not as powerful as expected, see Leica Geovid 8×42 HD-R (Typ 402) – Binoculars Today
But for visual, I find the Geovid right up there with the best.

Interesting. I think I saw you mention the steiner commander 7x50 are also among your frequently used binoculars. How many do you have exactly!? (Joke)

If the geovids didn't have the RF functionality would you still be using them? I recall actually seeing your post where you tested the accuracy of a few RF monoculars. Very interesting reading.

Thank you all three: John, Pinac, GvG for your work and posts.

We have investigated among others the Leica Geovid Pro 8x32 and the GPO Rangeguide 8x32 . Both are very well suited for use as a standard binocular and especially te GPO Rangeguide has a very good handling comfort as a standard binocular since the tubes are less bulky as the tubes of the Leica (a test of both binoculars is published on the WEB-site of House of Outdoor).
Users/hunters who are color blind can not use any rangefinder binocular as a rangefinder, since the red colored measured values can not be observed with their color blind eyes (personal communication from Jan van Daalen from House of Outdoor).
Gijs van Ginkel

Wow, it never occurred to me that color blind users couldn't see the LED displays. It really shows you how myopic (pun half intended) one's worldview could be. I assume the same thing might apply for certain, if not all, thermal imaging devices?

While subjective, I recall the kowa 6.5x bii having nice handling comfort. I wonder how the GPO would compare.

 

[John A Roberts]

Expanding on the data in post #4 above, regarding the degree of objective offset possible with different types of prisms in binoculars,
later in the original thread Kimmo addressed the degree of offset with the Canon 10x42 IS binocular
(the objective separation is fixed and the eyepieces swivel independently to adjust the IPD):

. . .
Firstly, the optical axis separation between the two objectives in the 10x42 L is 70 mm, which means that it gives a stereo base equal to bare eyes for people with 70 mm IPD, and slightly reduced stereopsis for those with larger IPDs and slightly enhanced stereopsis for people with smaller IPD's.
. . .

Kimmo

John