Optical boosters.

[Tony Z]

Recently there has been some guff about a new product available in the US marketed by Gene Davis which he calls the Optical Booster. Well as i have fooled around with optics and such for a while now i did a little investigating and found that this little device is nothing more than a glorified diopter. But after mucking about this weekend gone i found that they actually do work and not only that, they are available as a sort of filter aswell that can cut down on mirage quite a bit. No-one who has been to our range at this time of year needs to know why this is of interest to us all. Anyway the Davis booster is nothing more than a diopter that is easily obtained from a good camera shop and it just happens that the bloke next door and good mate owns one of the best camera shops in town. The diopters are available in sets of 1x, 2x and 4x. They can be joined together to make more magnifications if you wish, but aberations may come into play if the stack is too big.
The crux is that they do work and do add considerably more magnification than one may think, even i was suprised. The Davis booster is a Ziess, but the good mate next door tells me that there are two breeds of Ziess lenses, one is German and the other is Japanese. The diopter i used is a Hoya which just happens to be the company that makes the Ziess lenses in Japan. It's not a booster for riflescopes, it is a booster for video cameras and such. They come in many sizes and types, but the good thing is that they cost $69 a set of three lenses and an adaptor for some sort of video camera. Bin that and get a good machinist to make an adaptor to fit the lense to your scope and off you go. The Davis booster sells for $100 US and is only one lense with an adaptor for whatever scope you have. The Hoya lenses are not the only ones available, there are heaps of brands about at varying prices, but from what the good mate tells me these are the best value for money. By the way, they can be bought individualy and without an adaptor and work out to be about 15 bucks each. Not bad for a Japanese Ziess without the Ziess printed on the product. Have fun.

Tony Z.
ps, Some fellow on some forum in the US recently claimed that the 3x Davis booster added about a third magnification to his Leupold 45x to make it a 60x. I would agree that there is a substantial magnification increase but the amazing thing is that it does it externally so light dimming assocciated with extreme high powered scopes is not there. The one i used on my B& L 36 did indeed increase the target magnification substantially, but more importantly is that it gave a very pale blue image with virtually no mirage. Win win i reckon and is sort of what Peter Smith up our way has built into his rifle scopes and spotting scopes for years now. Don't get smarter when older, just slower. The one point i failed to mention is that it is possible to get a great increase in magnification by stacking these lenses together, but not loosing field of view like the 40x and 45 x etc scopes do.

[Dr G]

I used to use these sort of diopter lenses on my old film slr. I would use them to boost the standard lens to allow me to take macro shots. They worked ok but obviously not as good as a good macro. I had never thought of using them on a scope. great idea i will have to go dig them up from the shed

cheers Tony

Dr G

[ogre6br]

ok
so a 10X scope with a 2X diopter now becomes a 20X scope without having the small field of view that a 20X can have.

Where do you fit them onto the scope? front or rear lense? does it matter??
my front lense on my 10X is screwed for a mirage/antiglare adaptor- could I fit it to that??

Thanks
later
p

[Rinso]

ogre,

I don't think it makes a direct multiplication (ie 10 x and a 2x lens does not equal 20) I could be wrong though.

The Davis marketed system TZ is talking about has the advantage of being set up for various threads ie and adpation for Leupold, Weaver, B & L .. it however targeted to the BR market and is limited to those common makes and models common in BR.

It was widely discussed on Benchrest Central sometime ago .. do a search and find the thread.

cheers
Rinso

[woob614271]

Look out, TZ; I'll be bending your ear next time I see you...

[Harleyboy]

fellas, I have been in possession of a Davis 3x optical booster lens for about 3 months now & use it on my weaver t36 & can honestly say i dont know how i managed without one for so long.
boosted scopes have been around a long time & I own a couple of 25 x lyman scopes , the advantages over the old boosted scopes is that if mirage is really bad you can screw the booster off in seconds & drop back magnification. I own 3 weaver t36 scopes so effectively i have 3 45x power weavers at the ready.
Most my shooting is 50 yard rimfire benchrest but it allows me to place the dot inside the x ring much easier reducing eye fatigue during a match.
a pleasing feature of the booster is that while they are made to screw onto the rear eyepiece the lens doesnt distort when you move the booster across the back of the eyepiece while you look through it,so thre lens must be flat.
I have an old 24 x leupold tha just doesnt have enough magnification for the competitions i shoot so i got an old cheap tasco scope cover that fit the rear eyepiece & knocked the yellow lens out of it & placed the booster inside the cover ,slipped the cover on the back of the leupold & i had the 24 running the same as a 36 leupold,sharp & clear.

[Tony Z]

The 2x, 3x etc is not a mutiplication factor, it is a factory diopter standard that i don't really know what it represents. Even asking the camera experts left me wondering what the figure meant. The 10x scope with the 4x booster may be transformed into a 13 or 14 power. I think that in the future there may be a few BR shooters that were sorry to sell their old 36x Leupold Silver series scopes that had the lock focus ring as these were far and away the better scope compared to the newer 35, 40 and 45x side focus scopes. Just hunt around for the diopters as there are many and varied types with some like the ones i mention above that have real benefits on crappy light.

Tony Z.