Spotting Scopes: Observing Technique Questions

[Swivelhead]

Over the years I have accumulated a small number of quality optics, primarily binoculars. I began tripod mounting binos in the 80's. Gridding AZ's landscape with tripod mounted binos is one of my favorite ways to hunt.

 

Fast forward to 2010, the year I drew a sheep tag in southwestern AZ. Although I felt I was equipped for such a hunt with my stable of binos, in fact, I wasn't. The distances involved required higher magnification than my most powerful glass was capable of. 15's just didn't have the oomph to X-ray the mountains a mile or two out. Large, "big eye" binos were not an option due to cost. Packing the tripod & head required to handle such glass up and down mtns did not appeal to me either. So, it was time to break out my basically unused AT 80 Swaro scope that I'd purchased 10 years prior.

 

Up to my sheep hunt I'd never spent any real time behind a spotter. Using one eye quadrupled (or worse) the eye fatigue I'd experience using two eyes. Prior to the 2010 sheep hunt, the spotter got used sparingly to say the least.

 

My father is a lifelong amateur astronomer. When I was young, he encouraged me to look through his telescopes with both eyes open. Dad said I'd see more detail and be able to observe longer if both eyes were open. I was able to do this (although it was not easily accomplished) as my non-dominant eye was "in the black."

 

Scouting for my sheep hunt was proving difficult and I was having a tough time finding sheep. Don't remember how it happened but I began corresponding with Nick Heatwole. Nick put me in touch with Tom Saad. Tom and I had a number of conversations about sheep hunting. Among other things, Tom was adamant that I use my spotter and learn to use it with both eyes open. Basically restating what my father had told me many years prior.

 

Unfortunately, I am unable to get my non-dominant eye to shut off during daylight. Concentrating to the best of my ability I still get a double image. Currently, I have used the spotter long & often enough that I can comfortably close my non-dominant eye for long periods of time (hours). I feel confident that I am seeing the FOV well. I use my spotter often these days and when conditions call for long range observation, out comes the scope. Still, I'd like to learn to use both eyes as experienced scope users agree it is the way to go.

 

My questions to those who have mastered the technique:

 

1) How did you train your non-dominant eye to shut down during daylight?

 

2) Do you agree that more image detail is seen with both eyes open?

 

3) Can you comfortably observe longer with both eyes open?

 

Thanks in advance for your input.

[creed]

Years ago I worked as an instrument man on survey crews. Looking through optics all day was part of my job. I have no issues with looking through a scope. It is similar to shooting through a peep sight on a compound bow. I use both eyes open but use a squint which effectively shuts down my left eye. If you have too much difficulty use an eye patch. Some guys swear by it, others say it is useless.

[GJMauro12]

I use my spotter more than the 15s. If I don't have an eye patch I'll throw a blanket or something over me so only the end of the scope is showing. Once it's dark I can keep both eyes open.

 

Probably not the correct way but it works for me

[Mike S]

Years ago I looked through survey instruments as well with both eyes open and no problems. I can still use rifle scopes the same way, but have some strain with long periods behind a spotter. An eye patch takes care of that for me. You will see better with both eyes open, my understanding is that closing one eye results in an involuntary contraction of the other pupil.

[Swivelhead]

Thank you for posting your experiences and solutions. Contraction of the "in use" pupil does make sense to me. I'd be willing to believe that phenomenon would account for a degradation of the image.

 

I've seen competitive shooters wear shooting glasses that had a darkened strip on the non-dominant eye. After reading Mike S's post, suspect a contracted pupil may be why it is done. Think I'll play with some eyeglasses, probably remove the dominant eye lens and vary the "blackout" on the non dominant eye. I'll let you guys know if it works, could be the solution.

[Mike S]

For service rifle shooting I used to put a small piece of "matte" clear scotch tape on my shooting glasses at the spot where the off eye tried to pick up the AR's front sight, might work on a spotter if you were wearing classes.