What power lens should i shoot????

[Chris]

well im experimenting what lens would work best 4x or 6x???

[Flame]

4x covers all distances :D

[James Park]

If you look at the magnification they give you get the following. Assume a peep to scope distance of 0.8M.
0.25 diopter gives a magnification of 1.25 times.
0.5 diopters gives 1.67 times
0.75 diopters gives 2.5 times
1 diopter gives 5 times, but a lens this strong would be a big mistake.

I think that 0.75 diopters is the best all round choice (and is commonly referred to as "6x", but that nomenclature is fundamentally flawed as the magnification is related to the distance the scope is placed from the peep and is usually nowhere near 4 or 6 times - quoting the diopters is much more satisfactory).

[coach]

WTF James , just something like ' 4x would be fine" is all that was required . Not all of us have your knowledge and bamboozling us with all that info is confusing :o

[Flame]

Tried the 6x but found that the 4x suited me better :D

[Marcus]

I would recommend a 4x as it's easier to hold steady. 6x raises my heartrate when I use it outdoors. Try and see how you go.

[2Dogs]

Have to agree with the 4x

Even Clinterus and Mr Cousin's are using 4x these days.

[Shermo]

A new super clear 4 power lense for my Classic Scope will be arriving tomorrow:D

The lenses in these scopes are like looking through binos :o :D

There are also a number of other scope brands that make very high quality products

[2Dogs]

What?, ...... a cheap **** pair of Tasco's :wink: :lol:

[DrRalph]

WTF James , just something like ' 4x would be fine" is all that was required . Not all of us have your knowledge and bamboozling us with all that info is confusing :o


But why call it 4x at all? If you mean 0.5 Diopters then why on earth would you pluck a meaningless x4 out of the air and use that instead??

Jim is simply continuing the good fight against ignorance and misinformation. Which I wholeheartedly support. Thank you Jim.

[Flame]

Most people know what a 4x is but not many would know 0.5 Diopters or care :D

4x is used as another name for 0.5 Diopters. Don't fret boys :D

[Eberbachl]

4x for me :wink:

[Barry]

James,

I seriously enjoy reading your 'techo' stuff. But in this case there was not enough supporting info... I have no idea what you were talking about?

Perhaps you could give us a little more info on what you were getting at?

[Marcus]

I would also like to know the advantages and disadvantages of each magnification.
From my own playing around I have found
0x and 2x is the most relaxing to shoot, however you MUST not see movement
4x you will see movement you thought wasn't there, but still possible to hold dead still
6x will just about always move, so yu need to be comfortable with that.

I don't think a higher mag makes you more accurate, but I think a lower mag can make you lazy.

For the record Erika and Sten both use 2x lens.

[Robert de Bondt]

Have to agree with the 4x



Should we have to ask a Queenslander? They use XXXX from birth :wink: :D

[James Park]

Sorry about being a bit to obtruse.
The magnification you get from a lens depends upon the distance it is from the peep and also the strength of the lens.
As the distance gets closer to the focal length of the lens the magnification gets more and more and will be infinity at the focal length.
A lens with a focal length of 1M is defined as having a power of 1 doipter.
A stronger lens will have a shorter focal length: 2 diopters means 1/2 = 0.5M focal length.
A weaker lens will have a longer focal length: 0.5 diopters means 1/0.5 = 2M focal length. Similarly 0.75 diopters means 1/0.75 = 1.33M focal length.
"Diopters" is the nomenclature used widely within the optical industry (for example, spectacle lens are quoted in diopters).
The problem with using a 1 diopter lens is that the focal length is getting a bit close to the distance is is from the peep, and we can end up with extreme mangifications.
Another important aspect to consider is that in all scopes we have only a single lens element, and hence it will suffer from a number of significant abberrations (or image imperfections) which will increase as the magnification increases. For example, we will get distortions, lack of clarity, and colour imperfections. In a telescope, these abberrations are minimised by making the lens system more complex (multiple elements, for example).
A further consideration is that as the magnification increases we are spreading the same amount of light out over a larger image, and so the image become darker (which can be a challenge in some circumstances).
A further thing to consider is that as the magnification increases the field of view (how much of the target you can see) decreases. This is important for 3D or ABA, and also has the challenge that as you use higher magnifications you become more likely to shoot on the wrong target face in field rounds (as I have done a few times in major competition).
Where the nomenclature of "2x", "4X", "6x", etc, came from I do not know, but while it is in common use it is fairly meaningless. It tells you just about nothing about what magnification the lens will give, and certainly leads to the widespread misconception that magnifications are greater than we use in practice.

Regarding which lens to use:
I prefer a 0.75 diopter lens, and I do indeed find I can hold it quite still. I find I can aim more precisely with it than with a weaker lens. It is, however, not as clear as a 0.5 diopter lens. Also, for field, it can result in increased difficulty in seeing the target under some lighting conditions. Nevertheless, I have found it the best for me.
I have used a 0.5 diopter lens, and have found no advantages except for the increase in image brightness. As I noted, I can hold quite still with the stronger lens, so nothing to be gained in that respect. One reason you might use it is that the change in magnification will mean that when you are using the lens for gauging in FITA field you will get a different distance at which the target face exactly fills the lens (and indeed Bryce Lee uses a 0.5 diopter lens for field for exactly this reason, but a 0.75 diopter lens for target for the same reasons as do I).
Hence, I would see either 0.75 or 0.5 diopters as the usual selection for a target or FITA field archer.
For 3D or ABA I can see reasons for going to 0.25 diopters.
I can never see a use of a 1 diopter lens.

[Axilla]

Have to agree with the 4x



Should we have to ask a Queenslander? They use XXXX from birth :wink: :D

Too much XXXX can result in dual images :(

[GrahameA]

Good Morning James

If you think the 4X etc. nomenclature is confusing there have a look at what is happening in the (Digital) camera world!

This is the same issue as 'common' names and 'scientific' names.

[James Park]

If you think the 4X etc. nomenclature is confusing there have a look at what is happening in the (Digital) camera world!

This is the same issue as 'common' names and 'scientific' names.
A similar issue is the so-called "back tension" release devices. Very misleading. There is nothing special about those release devices and "back tension". Quite misleading I think, and can lead to incorrect form.
The reason I do not like this incorrect nomenclature is that in many circumstances it leads to people having quite an incorrect understanding of things. "4x" by no means gives a "magnification of 4 times" in virtually every case in which an archer uses such a lens. In fact a magnification of 4 times would be near unuseable.

[Barry]

James,


Thanks for the more detailed explanation. With a bit of extra reading I now understand the whole concept. Unfortunately this is an area where the average person is going to sersiously struggle with the more detailed concepts and I am afraid that commonalities like 4x are going to stick. :lol:

[fletch]

Jim,

The clarity of a picture in a scope also depends on a size of a peep sight hole. Using larger aperture brightens the image, and as a side effect it makes it less sharp (because of decreased depth of field). Positioning of the scope housing withing a target image can be a bit difficult as well.

What would you recommend on a combination of lense power vs peep size?

[James Park]

The clarity of a picture in a scope also depends on a size of a peep sight hole. Using larger aperture brightens the image, and as a side effect it makes it less sharp (because of decreased depth of field). Positioning of the scope housing withing a target image can be a bit difficult as well.
What would you recommend on a combination of lense power vs peep size?
Yes, agree with all that.
I generally go for a reasonably small peep to try to keep the image a bit sharper and to reduce the centering challenge. But that has its challenges for some indoor ranges and for some field targets where the light level is low.

[Ozzy]

Perhaps a "Clarifying Peep' would be the go for the .75 Diopter to sharpen the image up ? :o
The problem with a micro/small peep not only lack of light , but achieving a peep picture with your scope body unless the sight bar is extended out a mile :-?