Fresnel magnification

Most of you wanted to have a really BIG screen after flying your simulation for a short time.... So did I ! Ground targets are difficult to see, specially if they are moving targets; Bandits can be seen only when they are quite close (usually t it's too late at that time ;) ) and some of the instrument-data can be hardly read. So the usual first step is to change the monitor from 15" to 17" and after a while into 19" (some do even switch to 21"), which is an expensive procedure.

There is a cheaper way to have up to a 24" monitor: just by using a magnifying device placed in front of your actual monitor. These magnifiers called Fresnel can be found either under the mentioned name, or just under "TV Magnifying Lens". These last lenses can be found in TV shops, electronic markets, etc, and it might be cheaper for you to buy one of these instead of a real Fresnel. Prices run around $ 140,00 depending on the size you choose.

Screen magnification

Fresnel with frame

Lens curvature

Distorsion and reflections

Front view from pilot's seat

Position of mag. device

That's the result ! - Quite neat, right ?

Due to the curvature of the lens and concentric lines covering the front, you will encounter some smaller problems:
The concentric lines (which are needed to achieve the magnification) produce a slightly blurred image, specially if you are looking at the lens from a short distance. Also nasty reflexes may appear on the screen, specially if you have a light-source placed BEHIND you. This is really upsetting, and that was the reason why I allways flew in a complet dark room. Some other reflections might appear if you have a window behind the monitor. I could avoid this by building a glare-shield of acryl and covering the space between the monitor and the lens.

If the Fresnel is not completely paralel to your monitor's screen, distorsions may appear, specially at the corners of the lens. A key-stone effect is also present if the alignment of screen and monitor is not accurate. It takes some time to place your mag-device into the right position, but after jumping in and out your simulator for several times, it usually works. ;)

If you want even a bigger magnification, you can use 2 Fresnels instead of one. This meant lots of problems, as the distorsions of the first lens were magnified by the second one. Also reflections increased. After some time experimenting with the positioning of the lenses, I found out that the best position would be to place the first lens about 42 cm from the monitor. The second Fresnel about 2.5 cm behind the first one. This way the concentric lines matchet allmost perfectly, distorsion of the image was kept low and I had a screen of about 25" !!!
After covering the whole set with a glare-shield I was happy with the result. By coincidence the size of the HUD display matched precisely the size of my HUD-Frame, and the result can be seen in pic. 6 :)

Some small distorsions will be still present, and sometimes some images may appear a little blurry, but these were facts I could live with.

To zoom please select the picture with your mouse.
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