Andy McLachlan explains why there’s more to gain from scope image enhancers than simply removing glare from your lens
It always surprises me that I don’t see more scope image enhancers used on the HFT regional and national circuit. What we are talking about is a piece of rubber tubing that is a push fit over the ocular lens of a telescopic sight. Its primary function is really to reduce the opportunity of unwanted glare onto your ocular lens that might have a negative effect upon your sight picture. It certainly does a good job of doing this, shading the lens by a couple of inches at least.
However, the ‘enhancer’ also serves an additional and arguably more important function, certainly for me. What it does is to make sure that your eye remains perfectly in line with the scope’s lens system. Failure to make sure that you haven’t dropped your head – or indeed lifted it from your ‘dead-on’ central positioning, with your head resting on the stock’s cheekpiece – will induce the scourge of accurate shooting, the famous and highly unpopular ‘parallax error’.
I don’t know about you, but I have suffered from this major problem, particularly when I started outdoor airgun competition shooting many moons ago. Just moving your head about on the cheekpiece so that it is not perfectly lining up every shot will result in lots of misses and much frustration, as you swear blind that everything was lined up properly in your scope image. Well, it wasn’t! Following your setting of the parallax range on your scope, which cannot be altered during an HFT shoot (normally about 25 yards mid-course distance), if you do not make sure your head is in the correct position, errors will start to creep in. You will start to drop shots, often wondering why you have, which is very frustrating. It can put a newcomer off completely if they can’t understand why the aiming mark on the scope stops working properly.
Line it up
Some relatively expensive scopes are more fussy about parallax than others when it comes to the head position as you take the shot. The only way to find out if your scope starts to ‘do a wander’ is to try it with varying head positions and ranges, rather than the parallax setting you have set. Line up the crosshairs and try to get this central point image to move around on what you are aiming at. If you have parallax error, you will see that the crosshairs move as you change your head position. Not good!
How do we reduce this bad situation, apart from investing in a usually much more expensive optic, which will suffer less from the problem? A cheap and easy step is to get yourself down to your local gun shop and ask to look at a scope enhancer. They usually come in 60-90mm lengths and are available for about £12. We tend to use the straight rubber tubes rather than the specially shaped ‘pig’s ear’ type, although I did personally use one of these a few years ago, I now prefer the straight variety, and it lives permanently attached to my HFT rig’s scope. The 60mm size is usually the one that will fit best, as it allows average eye relief to be taken into account.
This quick and affordable solution will not only improve the image you can see through your scope’s lenses, it will also help to reduce parallax error. One of the ways it does this is by touching your eyebrow area (usually) to let you know that you are in the correct position for the shot. If you can’t feel the scope touching where it usually does, it will mean that your head position is incorrect and allow you to adjust it accordingly.
Very simple, I know – but like all of the best solutions, it actually works!