. Large negative dioptre range binocular (1 Viewer)

. The rather unusual Minolta compact AF binoculars 8×23, according to the instruction sheet, the dioptre adjustment range is -12 to +4. I can't recall having seen such a large negative dioptre adjustment.

This also apparently applies to the 10×23.

The field of the 8×23 is given a 6.6°, 115 m, or 345 feet.

IPD adjustment range 57 to 70 mm.

Autofocus
type pressive phase detection. I don't know if this is a spelling mistake or not.
Range 2 m to infinity
battery condition indicator (red LED)
power 3 volt CR 123 A or DL 123 A
working temperature -4°F to 122°F (-20°C to 50°C)
weight without battery 14.1 ounces (400 g)

Amazingly, the autofocus works well in room light and the image looks quite good.
But you mustn't keep the autofocus button pressed down, as it then starts to hunt for a new focus position.
Once you have found focus, you release the button.

Strange indeed.

There are other Minolta autofocus binoculars. I'm not sure of the date of this one, it could be that the leaflet is printed 1994 August and the Japanese sticker December 2001, but I'm not at all sure of this.
The binocular is marked Japan.
It has an on-off sliding switch. It doesn't feel particularly heavy.
The exit pupils are round nearly all the way to the edges.

. Regarding the last post, I suppose I have to commit the following to memory.

Battery condition indicator.
The red LED near the power switch indicates several battery conditions:
1. If the LED lights continuously for about four seconds after you turn the power on, the battery is good.
2. If the LED blinks four times for about four seconds after you turn the power on, the battery has only about one half its original charge and should be replaced soon.
3. If the LED blinks eight times for about eight seconds after you turn the power on, the battery is extremely low and could quit at any moment.
4. If the LED does not light, either the battery is dead or there is no battery in the chamber. My addition.

Auto Power off.
If, after approximately 2 seconds, you do not use either the autofocus or manual focus buttons, (I didn't realise you could manually focus this binocular) the power will automatically switch off. Pressing any button will restore power. If the battery condition indicator blinks after you press a button, then the battery has less than one half and should be replaced soon.

It will take me a while to memorise this.

. Having used the binocular a bit more, it seems to be quite interesting, although for most people it will be unnecessarily bulky and slightly heavy for the specifications.

The autofocus locks on almost instantly, probably quicker than focusing a normal binocular.
The instruction sheet says that if you are following a moving target you should keep the focus button pressed, otherwise press it to focus and then leave it.

The normal position for focus is the Infinity position. You could actually use it without a battery as an independent eye focus binocular.

It is not waterproof.

The manual focus needs a battery and there are two buttons for forwards and backwards.

The image is a little dull, maybe the transmission is not that high although there are multicoated surfaces.

The focus is achieved by moving a lens group or lens element backwards and forwards between the objective and the Porro prism. There is a surprisingly large amount of travel as it focuses.

I can think of two groups of people who might actually find this binocular very useful.

If in fact it has up to -12 dioptre range, then those people with short sight beyond -7 dioptre prescription may find that this is the only binocular available, although there may be others I'm not aware of.

Also, if somebody only has one hand, then this binocular is ideal as you can focus and hold the binocular with one hand.

The eyepieces seem to be distortion free eyepieces. The edge performance is reasonably good. There is a small amount of false colour, mainly at the edges.

An interesting, mainly concept, binocular. It is surprising how well the autofocus works, but it would be helpful if it were smaller and lighter or had larger optics for the same size.

Obviously, it was not successful in the marketplace. This example was bought new just now but from old stock.

. This Minolta 8×23 AF binocular is proving to be most useful.

In normal light here today, which is cloudy and dull the binocular gives fine high resolution images. Resolution is high or very high.
But what is most interesting is that it does what it says on the box, i.e. autofocus.
I use it generally for looking at objects 5 m to very distant and the autofocus generally takes one 10th of a second or occasionally as long as one fifth of a second to snap into focus.
I haven't really used it to look at flying birds, but I will try to see if it can autofocus on a small bird in flight. I suppose it might depend how the bird flies. Magpies, which seem to have erratic flight may be impossible to focus on.

It is a bit bulky and heavy for a 8×23 binocular, but maybe that is why it resolves so well handheld. It weighs 415 g with the battery.

It is my binocular of choice at the moment during daylight for looking outside the window as the very rapid autofocus makes twiddling a focus knob quite unnecessary.

It cost less than two ponies (or £49), and I consider this to be money well spent, especially as it was still new.