Scope questions

[Three-Fifty-Seven]

Howdy!

I'm looking for a new scope for low light ... I'm looking at the Leupold VX-R 2-7 X 33, which is a 30mm body with a 33mm objective ... My question is:

Will there be an advantage for light gathering with the 30mm tube over a 1" tube, since the objective is only 3mm over the main tube diameter?

I'm planning on putting this on a Ruger #1 375 H&H ...

[Doc Highwall]

Mostly 30mm tubes give more adjustment for windage and elevation.

[winelover]

I'd opt for a lower power variable, especially on a 375 H & H. Look into a lighted recticle also. You will lose the crosshairs before you can no longer see the game animal.

Winelover

[Jim]

A few years ago, I got a crash course lesson from an optics engineer on the "light gathering" thing in scopes. He said there's no possible way that a series of lenses can "gather" light. What makes the difference is quality and clarity of the lenses. He said the only type of optics that can make the picture brighter is the night vision type that actually magnifies light as well as image size.

I dunno, I'm just repeatin' what I was told.

[Three-Fifty-Seven]

I'd opt for a lower power variable, especially on a 375 H & H. Look into a lighted recticle also. You will lose the crosshairs before you can no longer see the game animal.

Winelover


2-7 power seems low to me .. And the scope is lighted ...

Mostly will be used deer and/or elk, possibly get East where the piggies roam ...

[Doc Highwall]

My low power scopes are 1.5x-6x42mm with 30mm tube.

[winelover]

Lower power would be something along the lines of a 1.25 X 4 or 1.5 X 5 or 6

Winelover

[Three-Fifty-Seven]

My low power scopes are 1.5x-6x42mm with 30mm tube.

Who makes that?

[Doc Highwall]

It is a Nikon Monarch Gold and has a 64' FOV @ 100 yards with 4" of constant eye relief.

[David2011]

A few years ago, I got a crash course lesson from an optics engineer on the "light gathering" thing in scopes. He said there's no possible way that a series of lenses can "gather" light. What makes the difference is quality and clarity of the lenses. He said the only type of optics that can make the picture brighter is the night vision type that actually magnifies light as well as image size.

I dunno, I'm just repeatin' what I was told.

Jim, I think the optical engineer might have done a bad job communicating some of his thoughts. The quality and clarity of the lenses is certainly a very important factor but astronomy scopes are rated by their diameter as the measure of light gathering. The first task of an astronomy scope is to gather more light than the human eye can gather. Magnification is the secondary task. As an example, consider the Andromeda Galaxy. It's twice the size of the Moon but it's dim and hard to see. A pair of 7x50 binoculars makes the galaxy stand out in a dark sky. 7x50s will gather about twice the light of 7x35s. An f/1.2 50mm camera lens will gather 4 times the light of an f/2.0 50mm lens. The difference is the diameter of the front objective. The 50mm number in camera lenses designates the focal length rather than the diameter. The f/number designates the diameter or brightness.

The 30mm tube, as Doc Highwall said, allows for more adjustment but it has no bearing on brightness. That is a function of the diameter of the front objective, the quality of the glass and the quality of the coatings.

Shawn, you may want a bigger objective than 33 mm for the best low light performance but a scope with a smaller objective and great contrast will out perform one with mediocre contrast and a larger objective lens any evening.

David

[atr]

I agree with David2011,,,,
the x33 objective is not the best for low light performance....try to find a scope with a x40 or
x42 objective...
also....stay away from glass coated with the reddish color coating....that coating is found on cheaper lenses and in fact blocks certain light wavelengths....
the greenish coated lenses work better as they allow a wider range of light wavelengths

[Doc Highwall]

Actually there is more to it then what has been said.

First optical devises do not gather light, they transmit it.

Each lens has two surfaces that the light has to pass through and each lens surface scatterers and absorbs some of the light not allowing it to pass through which means the more lenses the more of a light loss you have even with anti-reflective coatings.

Astronomy telescopes have fewer lenses then a terrestrial scope and the image is upside down allowing more light to pass through. Terrestrial scopes along with rifle scopes have a erector set of lenses to up-right the image, and scopes that have a zoom have even more lenses.

Scopes are made in two basic designs Reflector and Refractors.

A Reflector has a mirror like the Mount Palomar where the incoming light is reflected off a mirror to a second mirror then to a eye piece lose the least amount of light.

A Refractory has lenses only.

The optical formula for magnification is, the focal length of the objective lens in millimeters divided by the focal length of the ocular lens in millimeters equals magnification.

Now you have to take into consideration exit pupil of the optical devise along with the persons pupil diameter.

The military uses 7x50mm binoculars a lot for the soldiers for a reason, let me explain.

To find the exit pupil of a optical device like the 7x50mm binoculars you divide the objective lens diameter in millimeters by the power equals exit pupil diameter in millimeters.

50mm/7x = 7.1mm
50mm/10x = 5mm
35mm/ 7x = 5mm

From the above example you can see that the 7x50mm binoculars have a 7.1millimeter exit pupil while the 10x50mm and 7x35mm both have a 5 millimeter exit pupil. Even though the 10x50mm and 7x35mm have the same exit pupil diameter, the 10x50mm will be brighter due to the area of the larger 50mm lens.

Now you have to take into consideration the persons eye and their pupil size.
When a person is young their pupil can dilate to approximately 7mm maximum and as they get older it will not be able to dilate as much giving them a harder time to see when it gets dark out. This 7mm pupil size is taken into consideration when the optical devises are designed for maximum light transmission.

I said above that I like the Nikon Monarch Gold scope that is 1.5x-6x42mm. At 1.5x the exit pupil is 28 millimeters which is way over 7 millimeters and at 6x the exit pupil is 7millimeters.

I ask people if they can see a deer at 100 yards in a field and everyone says yes. Then I tell them that with this scope at 6x if I look at a deer at 600 yards that it appears at 100 yards or 1/6Th the distance because of the magnification. Then I ask them a second question, can you hit that deer at 600 yards and does your gun have the recommended 1000 foot pounds of energy at that distance.

The national average for shooting a deer is something like 46 yards and this is where field of view is more important then magnification. The 1.5x-6x42mm Nikon has just over 64 foot field of view at 100 yards and has 4" of constant eye relief so the shooter does not get a scoped eye.

In another thread I mentioned that there is a optical triangle that is governed by the laws of physics. Think of a triangle and at the first point you have magnification, at the second point you have field of view, and the the third you have eye relief.
The laws of physics say you cannot change any one of the points without changing one or both of the other points.

Think of the dangerous game rifles like a Holland and Holland 600 nitro express and if you have ever saw a picture of one with a scope, I know I have not. When hunting in close quarters even for dangerous game you do not need magnification, you need field of view with ample eye relief. The two best times for hunting are early morning and early evening when it is fairly dark and game will be spotted most likely with your naked eye or binoculars like 7x35 or 10x50. This is where optics can exceed the limits of the human eye, the question is how much.

I mentioned above about the 7x35mm and 10x50mm having the same exit pupil but the 10x50mm having greater light transmission or twilight factor but it comes at a price of a smaller field of view and/or shorter eye relief.

If you hold your binoculars or scope up at arms length you can see the exit pupil and measure it with a millimeter scale and see what I have mentioned.

The object of this is our eye is the weak link in using optics specifically our pupils. Example you are young and your pupils dilate to 7mm when it is dark out and you have a pair of 10x50mm binoculars with a exit pupil of 5mm, meaning that you are not getting any light for 1mm all around the outside of your pupil.

What makes this worse is our eyes have both cones for color vision and rods for shades of gray. The eye has cones only in our central vision for color and sharpness and as you go farther to the edge of the eye it slowly changes to all rods for our night vision. In the above example you can see that the cones are not going to get any light with a 5mm exit pupil.

When it is dark out and you do not have any optical devise with you you can help yourself to see better by not looking directly at the object you want to see by looking slightly to the side so you can see it using your rods in your eye.

There is a lot more with optics then I have mentioned here such as lens coatings and aberrations to mention a few and hopefully this will clear up some things.

[L1A1Rocker]

Have you ever considered a "Super Sniper" scope? I've never had one myself (although it's on my to buy list) but have read great reviews on them - especially in dim light applications.

[David2011]

David,

Please explain more on this contrast ... I like the Monarch scope Doc mentioned, but it does not have a lighted reticle (which I "think" I want)

The #1's need a bunch of eye relief too ... well ... so does the 375 H&H!

Another thing I like about the 30mm main tube is field of view

I will say that I got an old pair of bino's from my Father which I believe are 7X35, comparing them to a pair of Baraska 16X32 bino's I have ... The old pair from my Dad are way better early in the morning!

Good contrast doesn't add anything to an image. It's like incredibly clear mountain air. Poor contrast is more like looking through a light haze. With good contrast dark areas in the distance are well defined and rich in color. Highlights are crisp and snappy. Poor contrast washes out the dark areas to a grayish area with poor definition and highlights are less bright and undefined. Looking into the sun through a dirty winshield pretty much defines bad contrast. The spotlessly clean windshield with the sun low and behind you is an example of good contrast.

Next time you're in a store that sells better scopes, look through a cheap scope and then a really good one, preferably both having similar specs like 3-9x40. Set them both at the same power. Look into a dark corner of the building with both scopes. Good contrast will reveal itself when you realize that the better scope not only looks brighter and sharper overall but you can see the details in the darker area much more clearly with the scope that has good contast. As with the binocs, your Dad's better optics give you a better image even at lower power.

The 30mm tube will not increase the field of view. The field of view is determined by the design of the scope's eyepiece. Back to astronomincal telescopes, they can get, for example, 150 power with a narrow or a wide field. The inexpensive entry level eyepieces give a narrow field while a high dollar wide field eyepiece will show more sky at the same power. Rifle scopes are subject to the same design issues.

While it is true that the job of optics in to transmit light, they absolutely do "gather" light. Transmission is a function of the quality of the glass and the coatings. Scopes with fully multicoated lenses throughout will be more likely to have higher transmission and better contrast. The coatings let the light pass through without as much reflecting back off of the surfaces and bouncing around in the scope's tube. That reflecting light causes poor contrast and less of the light that strikes the objective getting to your retina. A 30mm objective lens brings the photons hitting 706.5 sq mm of objective lens to the exit pupil and to your eye. A 50mm objective will bring the photons hitting 1962.5 sq mm of objective lens to the exit pupil and your eye. Result: the more light collected, the brighter the image assuming other factors being similar like glass and coatings. The general consensus of optics designers is that the exit pupil should be 5-5.5 mm as the mature human pupil will only open to that size. An exit pupil larger than that wastes light and field. That is purely hearsay. I'm a shooter, former pro photographer and amateur astronomer- not an optics designer. I have, however, owned enough bad scopes to be willing to spend more these days.

It's hard to argue against the lighted reticle but you want one that can be dimmed WAY down. A buddy and I tried to hunt hogs at night with red dot optics and found that the red dot couldn't be dimmed enough to let us see past the optical sight. It glared and flared so much that we couldn't even see the motion detector lights on the feeder 30 yards away. If you have a dark animal against a dark background in the last minutes of legal hunting, the black reticle is going to be hard to see and some gentle illumination would help.

Inadequate eye relief with the .375 H&H could lead to close encounters of the worst kind. How would you ever get over that kind of flinch?

David

[barrabruce]

Wow good info.
The super sniper line of scopes and the reviews that I have read are from the suppliers site and its mates.
I am not saying either way that anyone may be biased or not.
There are a lot of leupy bashers out there...:)
I have not seen any real hard data on the SS stuff except from someone's word.
With no data to back it up.
Ahh opinions on scopes that the elightend ones haven't even bothered to look though nor test out nor side by side
I would to see a 1-4/5/6x round up scope test with all the latest gear available.

I cannot say they are ****e nor fantabulous As I have never seen one. Nor a lot of the other brands.

Sure they are better scopes than leupy but at least I know what I bought. and what I got.
I would love to have had the importunity to eyeball other scopes and test them out.

I can say though looking through the mk4 1-5x spr is like looking through a new clean window.
I can still see things better at 5x on twilight with the small objective than with "my" eyes.
It is just sharper and good enough for me.
At the range I can see better definition with this scope than one with a 3x-9x x40mm power reasonable priced scope.

The illumination stands out in broad daylight if you are looking into the shadowy scrub well enough.
The latest release model.
I bought this scope cos it ticked more boxes for me than others available.

If you look in to the big game sites the 1-4.5x leupy. Nikon monark???something or other and I believe weaver 1-3x are what the elephant and buff snuffers prefer for good reason. Not cos there cheap nor dear thou.

There has been a whole lot of new 1-4/6x ish scopes to ponder over.

Shiver me timbers if I have to shoot that far that I need a big scope then I'll drive a bit closer before I get out and walk.

Barra

[David2011]

I put a "good" Bushnell, retail around $250, on my AR-15 when I lived in East Texas and mostly punched paper. It was a 4-16x50 with adjustable objective and was adequate for the task. When I moved to New Mexico I went from paper punching to practicing in the desert and looking for live targets. One of the first issues with the Bushnell was the contrast. What had worked just fine with the afternoon sun behind me shining on the paper targets suddenly couldn't help me find a small chunk of rusted steel that I had set on a rock as a target. I was trying to develop ranging skills and learning to use the Harris bipod I had added to the rifle. The metal blended in with the environment through the scope even though it was considerably darker than the rocks and sand. Rust is a natural color and seemed to be a darker shade of the same overall color of everything in the environment. I replaced it with a Nikon Buckmaster 6-18x40 which has micrometer type target turrets, decent transmission and contrast and good power for little targets at 200-400 yards. I think the Nikons are one of the great values in good scopes and am definitely biased toward their glass after making a living with Nikon cameras for many years. So, now I have a nice flat top AR that will hold 1/2 MOA at 200 yards with Win 748 and Hornady V-Max j-words. It has a 16" bull barrel and a Harris bipod that's tall enough to use sitting on the ground. It shoots as well as I can reasonably expect from an AR-15 but when I start walking across the sand hills that is one HEAVY rifle. Yes, there is a point. I put together a combination that was all I wanted in an AR because I bought it when I lived far from the desert. I missed being able to take an offhand shot at a jackrabbit over the weekend because the 6-18 power scope was set on 18X. I couldn't find the jackrabbit before it ran off where it was no longer visible. Even though the rifle is now exactly what I wanted it to be it is not the best mid range setup. Unless I find prairie dogs the rifle is too heavy and has too much scope for 50-200 yard shots. Even then, I will probably need to buy another Harris bipod to shoot from a prone position or off of a bench. An accurate light to mid weight AR with a 3-9 scope and shooting sticks would serve me better for coyotes and other local varmints.

Lessons learned: Heavy rifles, even an AR-15 aren't much fun to carry very far. Should have bought the better scope to begin with. It helps to know what you will do with a gun before you buy it. In defense of that statement, I had wanted a bull barreled flat top AR for some time and when Nancy Pelosi became Speaker of the House I bought it because she didn't want me to have it. I don't regret the purchase but at about 12 pounds it isn't the best choice to tote over a quarter mile of sand hills to a coyote stand. I hope all of my rambling helps at least one person.

David

[Lloyd Smale]

I agree with the others a 30mm tube doesn nothing but add adjustment range to the scope. Bigger objectives help a bit but the biggest differnce you will see in low light will be the quality of the lenses and how well there installed in the tube. Id say its 80 percent lense quality and 20 percent objective size. Once you step up to a scope with decent glass like a nikon monarch or a leupold vx2 or better you wont notice much improvement buy going from say a 40mm objective to a 50. Even a 32 mm objective in a scope with good glass will gather light as good as your eyes will allow. Then you go more the 40 mm you have to deal with mounting the scope in high rings which makes it awkward to use. Bottom line for me anyway is the only thing a large objective scope really does is make a cheaper scope gather a bit more light but then anymore i dont buy cheap scopes.

[barrabruce]

What are you going to shoot?
How far is the normal expected range? 80-90 % of the time.
200 yrds I'd say 4x but thats just me.
a 1.2/2x-4/6x I would still have a crack at bunnies with it out to as far as I could see-um.

I have my gun which I can carry all day and shoot what I want out to where I can hit them.

I'd prefer balance over power if it comes to the crunch.
I like my gun to come up and point naturally like a shot gun and not have to handle a top heavy thing I have to "look" through the scope to see something.
As always your mileage may vary to mine.

Barra
I need the adjustments other wise I would have gotten a 25mm tube.

[1Shirt]

Guess I am just old school. I would recommend a 2.5 or 3X Weaver, because they just plain work. I have a 3X on my #1 in 375H&H, and it works fine for anything I intend to hunt with that rifle including African game.
1Shirt!:coffeecom

[Doc Highwall]

123.DieselBenz, let me know how you like it after you get it mounted. After I bought my first one and mounted it I knew I was going to order another and now I have three of them.

[RobS]

Sorry about that, I didn't catch you mentioning that you went ahead with the Monarch Gold. I think you'll be very happy with it's clarity and light transmission. Keep us up on your review!!!

[RobS]

It never crossed my mind that Sightron wouldn't have lower powered scopes. I guess when I was looking I wasn't in the market for as low of a variable scope magnification as what you are wanting.

[Doc Highwall]

Now you know why I recommended it, and why I have three of them.

[Three-Fifty-Seven]

Now you know why I recommended it, and why I have three of them.

Thanks Doc! :bigsmyl2: