Real Telescopic SIghts for Compound Bows

[NeilM]

I am sure Leupold used to make a pistol scope, or at least a scope with very long eye relief. Worth looking round the 'net'.

Now I understand your application, I think my comments about parallax are less relevant. If you are shooting at a fixed disance all day, or even moving two or three times, you would easily be able to set the scope for each distance.As I am a field archer, I always imagine that scenario.

[geoffretired]

Hi Timujin.
Sorry! I thought STS was shoot through system.
If I had thought of the idea, I would want to see it through. I think some people are just like that. I hope I didn't sound negative in my responses, I really was trying to save time by highlighting possible difficulties.
I have seen some sights recently where the up/down rack is on the bow.
Arten Olympic and one by AGF. They are sturdy enough to allow a scope to be fitted somehow. The up/down would then be taken care of using that sight's adjustment. A tilt adjustment would be possible, to bring the alignment you require. The crescent shape is used on a copper john sight I believe, but I would not want to attempt making that with the machines I have.
Do you envisage the scope in the sight window? Or is it somewhere else?
Is there someone on the forum who knows how to change the eye relief of a scope? I'd be surprised if there wasn't.
Count me in on it; and can I charge exorbitant prices as your sub-contractor?
All the best
Geoff

[3rdof5]

Hi
Just having a look at my arten summit II sight, would it not be possible to modify the sight tunnel bracket, less messing about and it still gives you the up/down movement on the scope, not too sure if you`ve seen/or got one but there are only two screws holding the sight tunnel to the main up/down mech, so all you would really need is a bracket making up to fit back onto it with fixings for the scope.
just a thought.
nice idea though

NeilM

I had a look at the Leupold plus every other handgun scope sight and the only one that has a constant eye relief of 20 inches is the Bushnell. The others have ER starting at 24 inches or so for the very lowest power(1.5X) but then reduces rapidly to about 9 to 10 incehs as one approaches 6X - which isn't much use.

I'm going to talk to a mate of mine regarding playing with lenses to see what the problems are with fixed mag and very long eye relief. I don't know a hell of a lot about optics but I can't believe the problem can't be solved ((stubborness or optimism???)

Geoff - not a problem. As I said I don't mind constructive criticism and I've always found your remarks very useful and insightful.

The problem with the mount is this. It will either have to be along the lines of the Copper John curved sight bar (which in my view is the preferred option because it couples range changes with orientation changes at the same time).

I know the Arten, AGF, Spigarelli and Angel riser mounted sight racks and they could be adapted fairly easily but they have their own attendant problems as the following will show.

I envisage the scope being mounted in such a way that it fits inside the existing sight window on compound bows. That in itself is no great problem.
The other possible mount is a pivot mount which allows the scope to turn about a central axis but this brings with it several problems, not the least of which are, firstly that range changes, being accomplished by rotation about a central axis, would involve really small scope movements (always difficult) and a constantly changing anchor point (not good).

One could simply use an existing sight and mount, mount it backwards on its fitting, and connect the scope to the existing scope holder (with some modifications of course). The problem with that is that as the range changes, one has to reorientate the scope so that the optical elements stay lined up with the eye and that is not a simple exercise, but it can be done. It's finding a simple repeatable way of doing it that remains the problem.

It may not even be necessary to have a real scope at all, just some of the lens elements mounted appropriately. This is the issue I intend discussing with my friend.

As I said, I need to think a lot more about the issues involved and whether the amount of work involved balances the benefits to be obtained.

Geoff, I'll keep your offer about being a sub-contractor in mind

[provins]

I'm finding this a really interesting thread and I do hope you find some of the answers to your questions Timujin.
I shoot unsighted bows but I've often wondered why some one hasn't yet put a tele sight on a compound bow,I look forward to seeing how you get on

[geoffretired]

More ideas flooding out.
I wonder if 2X isn't the best magnification? I can't hold that steady and more mag =more apparent shake. 6X might move the gold out of view under normal shooting conditions.With 2X the ER would be 24" or good enough??
Next thought. Getting the scope to tilt for different ranges could be achieved by fitting two racks and doing more adjustment on one than the other.That would add rigidity to the mounting and allow for lighter racks(compensates for having two)
Another method is one rack and a platform with a ramp that can be jacked up at one end with a screw thread. Fine tilts can then be achieved and the number of turns could be counted and used when putting it back to its starting position.
Also, I asked a question on the off topic section about changing ER; there may be responses there soon.
Photos of finished article are expected soon! Or sketches will do if you don't have a digital camera.

[provins]

Just a thought but have you thought if the scope was fixed and use the mil dots for different ranges?

[simon m]

Originally Posted by provins

Just a thought but have you thought if the scope was fixed and use the mil dots for different ranges?

He's not just a pretty face this one!.

Sounds good in theory....like a four pin field sight sorta fing

[geoffretired]

Would the dots be far enough apart to duplicate the different positions of a normal sight? It would work for distances that are not too far apart; 30m perhaps.Just a thought.

Geoff

Photos of finished article are expected soon!

Hell - don't hold your breath mate. I'm still thinking about this.
If you get some answers on ER I'll be most interested.

provins

I don't think the dots would cover from 18m to 90m, worse luck.