I recently bought a Leupold American Marksman. The scope is said to have fast focus. While I have used the scope, I still don't understand what "Fast Focus" means. The scope still has micro threads and the rear optical is screwed in or out to focus. Is there a correct way to set it up, eg screw clockwise to the stop/end and then unscrew, or something similar?

Generally, the way to use those things is to aim at a featureless wall or cloudless sky and turn the focus back and forward until the reticle comes into sharp focus. Do it in good light and it will be set for most purposes.

The only real advantage with fast focus is that our eyes do change their own focus in very poor light. So, if you are hunting very early or late, aim at the sky and turn the focus until the fuzzy reticle becomes sharp again.

quote:

Originally posted by sambarman338:
Generally, the way to use those things is to aim at a featureless wall or cloudless sky and turn the focus back and forward until the reticle comes into sharp focus. Do it in good light and it will be set for most purposes.

The only real advantage with fast focus is that our eyes do change their own focus in very poor light. So, if you are hunting very early or late, aim at the sky and turn the focus until the fuzzy reticle becomes sharp again.

Is the fast focus just about the reticle rather than the clarity of your target?

I was always under the impression that the term fast focus applied to scopes with a focus ring on the rear of the objective lens i.e. marked up - & + enabling a quick turn back or forwards to bring the reticle and target into as sharp a focus as possible. The leupold focus of unlocking the lock ring and turning the whole objective housing on its fine thread is a PIA and slow.
The beauty of the fast focus is that the scope can be quickly focussed for another shooter or for the shooter who may wish to remove his glasses if they have fogged due to rain or sweat. This is one of the reasons I have now gone to Vortex scopes in the low end bracket. Along with bloody stiff vari-power adjustment and fiddly scope adjustments, the low end Leupolds have lost traction for me.

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Originally posted by eagle27:
I was always under the impression that the term fast focus applied to scopes with a focus ring on the rear of the objective lens i.e. marked up - & + enabling a quick turn back or forwards to bring the reticle and target into as sharp a focus as possible. The leupold focus of unlocking the lock ring and turning the whole objective housing on its fine thread is a PIA and slow.
The beauty of the fast focus is that the scope can be quickly focussed for another shooter or for the shooter who may wish to remove his glasses if they have fogged due to rain or sweat.

This is what I thought also, so I don't get it with this scope.

Looking at the pictures, I imagine the fast focus on the Marksman works something like the one on an old Nickel scope I've got. The threads look as fine as a slow focus but have a greater pitch, whereby one turn out of the ocular will move it 3mm and expose 4 threads.

Generally, this focus does work mainly on the reticle, though some picture focus and even change of power may occur. The main way to change picture focus, if needed, is through parallax adjustment, if you are lucky(?) enough to have a side knob or the older objective type.

I have wondered if this parallax adjustment could be used as a rudimentary range finder (focus the target then look at the dial) but doubt it would be that precise, if I remembered to look. As with dedicated range finders, I have found that when the critter you want turns up there's a tendency to forget about the extra stuff, just estimate the distance and take the shot.

Thanks for a great responce. The threads really don't look all that different than other scopes I have without fast focus. I have an email to Leupold asking them to explain the scopes fast focus.

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Originally posted by onespeedbiker:
Thanks for a great responce. The threads really don't look all that different than other scopes I have without fast focus. I have an email to Leupold asking them to explain the scopes fast focus.

Good idea, please post their response if you get one.
Other reason I like the 'true' fast focus i.e. ring on rear of objective bell is that when changing the power on a vari-power scope and sometimes even with change of light, the ability to simply refocus the scope slightly is of benefit, just as you do with binoculars.
This can be done easily when setting up for a shot with a Vortex or similar scope but not on scopes needing the objective bell to be unlocked and turned on a fine thread.

no locking ring makes them fast focus

Well the mystery has been solved; the American Marksman scope, regardless of the fact that it advertised as having fast-focus, does not. I emailed a Leupold representative who replied, "The American Marksman is not a Fast-Focus eyepiece, it has the traditional lockring style diopter adjustment."

When I asked why it is advertised as such, he said "This is a great question! I have put a question in with our Product Line Manager for that particular scope, who is also responsible for Specs, and product descriptions for that scope on the website. I have also asked that they remove that description from the website. While it is a lockable adjustment, and 'fast' is a relative term, I am in agreement with you, that it's not accurate.

Let me know if you have any additional questions. Sorry if this has caused any inconvenience.

As a result I returned the scope and upgrade to a VX-2.

It's not surprising to me that Leupold employees have no clue about their own products. When the VX-5HD was introduced, I inquired about the duplex reticle in a particular model. I wanted to know if it was the same duplex used in the VX-R 3-9x40/50. That reticle is bolder/heavier than their standard offering.

I was assured in multiple statements that it was indeed the same.

It is NOT...and not even close.

Well, if nothing else, perhaps it is all a clue that ... the supreme commander of the nation and colonies may be a fraction raiment challenged.

quote:

Originally posted by sambarman338:
Looking at the pictures, I imagine the fast focus on the Marksman works something like the one on an old Nickel scope I've got. The threads look as fine as a slow focus but have a greater pitch, whereby one turn out of the ocular will move it 3mm and expose 4 threads.

Generally, this focus does work mainly on the reticle, though some picture focus and even change of power may occur. The main way to change picture focus, if needed, is through parallax adjustment, if you are lucky(?) enough to have a side knob or the older objective type.

There looks to be something to what you say. One thing I did notice is the rectile remained in focus regardless of the position of the eyepiece.

There should be some change in sharpness, onespeedbiker, but maybe what you're getting at is that reticle focus is not necessarily all that important.

I've got an ancient Nickel Marburg (army?) scope with no hand-adjustable focus. Presumably this made it more waterproof and, since recruits would have had their eyesight checked before acceptance, all would be expected to see the top of the #1 reticle's blunt post, even if a bit fuzzy.

In my book on scopes, being printed this week, I put forward the idea that scopes for hunting in rainforests etc should be made with no adjustments that might possibly let moisture in, assuming that the hunter is already wearing corrective spectacles if his sight is not 20/20.

quote:

Originally posted by sambarman338:
There should be some change in sharpness, onespeedbiker, but maybe what you're getting at is that reticle focus is not necessarily all that important.

I've got an ancient Nickel Marburg (army?) scope with no hand-adjustable focus. Presumably this made it more waterproof and, since recruits would have had their eyesight checked before acceptance, all would be expected to see the top of the #1 reticle's blunt post, even if a bit fuzzy.

In my book on scopes, being printed this week, I put forward the idea that scopes for hunting in rainforests etc should be made with no adjustments that might possibly let moisture in, assuming that the hunter is already wearing corrective spectacles if his sight is not 20/20.

Good to get an answer back from Leupold, it was as I thought, not fast focus. I did have a senior moment and mixed up my terminology in my earlier post when referring to the adjustable objective lense, should have been ocular lense.

I have just had a Leupold experience at the weekend when shooting in my sons 7mm-08 Weatherby Vanguard after having free floated the barrel. It is fitted with what was my VX1 Leupold but when looking on target the crosshair was out of focus for me when wearing my spectacles which give me 20/20 vision. I shot without my glasses and the crosshair was then in focus. I thought my 23 year old sons vision would be 20/20, he has never said otherwise. Had the scope had fast focus I could have quickly adjusted it for use with spectacles and returned it to his setting.

This is the beauty of fast focus in the field where a scope focus can be changed quickly to suit users, range and light.

I'm always a bit concerned over water or gas tightness when seemingly quite freely turning the ocular lense housing on scopes, including Leupold, to focus. Doesn't seem to be any O'ring resistance when turning if this is how they are sealed?
Sambarman you should know the answer to this?

I'm afraid I don't know the answer, eagle27, but I have seen the opposite. Some of the old European scopes had a little screw in the side of the ocular housing to lock a focus setting to stop others fiddling with it, if you did not want to change it much yourself.

I also bought a first-generation Swarovski that would not turn at all and the company couldn't help as they don't service those any more. Finally, I cooled the scope in front of the air-conditioner and put a microwaved wet cloth around the ocular and got it to turn.

Prior to about 1972, I don't think any scopes had O rings. An old Nickel I dismantled only had graphite grease under the variable power ring. Since then I tape the power rings and focus, leaving a tab in case I really want to remove them quickly. You could try that if you worry about moisture getting in.

quote:

Originally posted by sambarman338:
I'm afraid I don't know the answer, eagle27, but I have seen the opposite. Some of the old European scopes had a little screw in the side of the ocular housing to lock a focus setting to stop others fiddling with it, if you did not want to change it much yourself.

I also bought a first-generation Swarovski that would not turn at all and the company couldn't help as they don't service those any more. Finally, I cooled the scope in front of the air-conditioner and put a microwaved wet cloth around the ocular and got it to turn.

Prior to about 1972, I don't think any scopes had O rings. An old Nickel I dismantled only had graphite grease under the variable power ring. Since then I tape the power rings and focus, leaving a tab in case I really want to remove them quickly. You could try that if you worry about moisture getting in.

Thanks for your reply, I suppose a graphite grease on the multiple fine threads is probably a good seal, there maybe a fine O'ring involved too but on the VX1 Leupold at least, I can't feel much resistance when turning the ocular housing to focus the scope.
The fast focus on the rear of the ocular housing of scopes with the fast focus feature certainly feel as though there is a good O'ring or two involved as they have quite a good resistance when rotating + or - to adjust the focus.

O-rings aside, Eagle, my problem with variable waterproofness is the long slot they have to connect the power ring with the scroll. Some scopes twist the whole ocular housing to change power, of course, and I suspect this might be more waterproof. I tend to use the highest power only at the range or if sitting out really late or early. Otherwise, I set the power at the lowest power possible without invoking tunnel vision - and tape it up.