Introduction to Optics

[Scythe13]

Okay, hidey-ho campers.

Time for a little bit of help with getting to grips with optical enhancing equipment, e.g. binoculars, monoculars, and scopes. Granted there may be a load more, but since these are the 3 styles I'm planning on utilising, these are the ones I've learned stuff about.

I'm going to do this in a self created Questions and Answers session.

Q1. What the hell are optics?

Optics is the name given to items that allow your eyes to have enhanced vision. In the context we're using, it'll be focused on seeing a further distance. Technically glasses would count as optics, but that's not something I'm going to cover.

Q2. What the hell are those complicated number things about?

With optics you will get either 2 or 3 lots of numbers. The numbers will be in 1 of 2 formats. First, with 2 lots of numbers, it will look like this AxC. For example, 4x32. If it comes in a 3 group format, it will look like this A-BxC, for example 4-10x50.

The first number, or first 2 number groups (if it's a 3 lot of numbers) is the magnification. So, in the example above, it it's a 4x32, that means the optic has 4 times magnification. If it's a 3 lot of number, e.g. 4-10x50, the - sign means it's variable zoom. So the zoom can be from number A to number B. To use the earlier examples 4-10x50, it means variable zoom from 4 times magnification, all the way to 10 times magnification.

Now, time to explain the last number. The last number is simply the size of the lens on the front of the optic, in millimetres. By the front, I mean the part furthest from your eye and closest to what you're looking at. So, the above examples are talking about a 32mm and a 50mm front lens.

Q3. Why would you need different levels of zoom?

The amount of zoom required depends on what you're using the optics for. The more you zoom, the narrower your field of vision gets (this is a generalisation and not always 100% correction, but it's about 90% right). By this I mean the smaller the area you're able to see at any one time. So, if you're using a 4x optic or a 10x optic, the 10x optic will typically have a narrower field of vision. The field of vision is measured in degrees.

The second reason you'd want different levels of zoom, because you may well be looking different distances, or wanting a better view of the same distance object. There are all manner of different reasons.

Q4. Why is the size of the lens important?

The size of the lens can make or break an optic. The larger the lens, the wider the field of vision. More importantly, however, the more light that will enter the optic. This means that you'll get a much clearer picture in the day, but also at times when light levels are decreased, e.g. dusk or dawn. You can tell a late or early hunter, because they will have a huge lens on their scope.

So, if you use the example of a 4x32 against a 4x50, all things being equal, the 4x50 will give a clearer picture in the day, and will be more effective during the very early morning and later evening. The 4x32 will be lacking the light intake for the very early and very late hours, thus it's 'effective time' is much lower than the 4x50.

One last element about the importance of the size of the lens...weight. If you're a stickler for cutting weight, the optic with a smaller lens should weigh less, and thus you can make a pretty good weight saving by choosing an optic that fits the times you plan to use it in.

Q5. What is the best kind of optic to use?

This is a hugely varied question. I hate answering a question with another question, but the fact of the matter is, you need to be more specific. The best optic will depend entirely on what you're using it for. If you're off hunting, a good set of binoculars, with correct zoom and light intake, will be ideal for grid searching the landscape, then a spotting scope, with high variable zoom, and massive front lens, for getting a better ID on what you intend to shoot, and then a scope that has sufficient zoom and light intake, for your situation. Pretty complex hu? With practice, you'll refine your optics.

If you're just checking out a bird species to get enough data to ID the bird, a reasonable set of fixes zoom binoculars, or maybe even a monocular, would be sufficient. You don't need to pinpoint the exact details, but just pick out broad-stroked data points, for the recognition.

Q6. Do I need to spend a crap load of money? I've seen binoculars for over £600!

Well, this is where some people will go crazy at me, then others will agree with me and smile. So please...deal with my response and suck it up.

Yes and no, both at the same time.

I've used cheap crappy optics and been very unimpressed with them. I've also used cheap crappy optics and been pleasantly surprised. I've had some semi-expensive ones and preferred stuff I already had that were less than half the price of the semi-expensive ones. But the truth is, try out as many different types as you can, before you fork out any semi-large amounts of money.

When I first picked up a Swarovski scope, I wasn't too impressed...aside from the price tag on it. However, when I looked through it....DAMN!!! WOW!!! THAT MAKES SENSE!!! With companies like Swarovski and even Delta, they are able to charge a much higher premium, because their products are amazing! If you are able to afford this kind of optic, you will benefit from their greatness. Try one and you'll see what I mean.

Having just said that, could I justify spending £1000 on a scope? Not when the gun costs around £200, I can't. However, if the gun was closer to the £900 mark, and looking for 700 meter ranges, then I'd definitely be looking at a £1000ish scope. To do otherwise, would be to short-change your gun's abilities.

This is where the 'tight with money' crew get all up in arms and start crying bloody-murder. But the fact of the matter is, if you pick up a very high spec scope, and a cheap scope that have the same 'spec', the difference in quality should be screaming at you. If you can't see the difference, then you must honestly be blind, or the expensive optic is a fake. If the difference isn't screaming...buy the cheaper one...obviously.

It wasn't until I picked up a very-high end scope and looked through it, that I genuinely appreciated the VERY wide range of costing. It was one of those epiphany moments where you can't help but to say "Oh, I get it now."

But as I've already said, you do not need to go high on cost to get benefits from your optics. A simple monocular with a large front lens and a good magnification, can be pretty damn good and pretty damn cheap too.




I hope this information helps.

Enjoy.