Paul, When doing side-by-side tests in low light, I've found that it is not easy to insure that both scopes are set to the same exit pupil size and magnification. You would have to share the details of your side-by-side comparison for me to understand why the Leupold lost.
Thanks Bruce. I was hoping you would take the time to respond, since I know you're in the scope business, and more up to date and knowledgeable on current scope offerings than I. I'll provide some information to allow you to evaluate my testing. I know that exit pupil is a by product of objective lens diameter divided by power magnification. I didn't adjust power magnification to create equal size exit pupil diameter during my light transmission testing. I realize that the larger diameter objective scopes have the advantage for light transmission under low light conditions, given equal power mag settings. I wanted to compare the actual scopes I owned against one another at equal power settings as the light dimmed, because that's how these scopes would actually perform for me during field/hunting use. Not trying to upset Leupold loyalists, but the light transmission tests on the VX-3 2.5-8x Leupold I owned was disappointingly poor. The difference between the VX-3 and the Zeiss and Sightron SIII was huge. This was the newer VX-3, not the older VariX III. The difference wasn't subtle. There was a lot of difference. No comparison. My buddy came to the same conclusions on light transmission, so we had two sets of eyes reaching the same conclusion.
All resolution testing was also performed at equal power settings across the scopes being compared for resolution. If the lowest powered variable scope maxed out at 8x, then all the other variable power scopes were set to 8x.
I searched the Forum for the comparison testing information I posted following two scope comparison tests. Looks like the first comparison testing was completed in 2007, before I owned any Sightron SIIIs. This Post is dated June 17, 2007.
http://www.longrangehunting.com/forums/f18/ior-scopes-22912/index3.html#post157764
So my initial test was completed prior to June 17, 2007. I provid this to give information on the versions of the various scopes being tested. Some of the manufacturers' scopes today may not be built the same as they were back then.
I also have read praise regarding the light transmission of IOR scopes but it has always been a 2.5-10x IOR or one of the other IOR 4X power magnification scopes. I've read a lot of forum posts including Snipers Hide, Snipers Paradise, 24 hourcampfire, and many articles, and don't recall a single post or article where anyone has done side by side light transmission comparisons with an IOR 6X power magnification scope. If you're aware of any, I would appreciate your posting the web address so I can take a look. A buddy and I went out one winter evening and compared the following four (4) scopes for light transmission, one being my IOR 3-18x 42mm. We both came to the same consensus, from brightest field of view to dimmest field of view. We did turn all scopes to the same power setting for this comparison.
1st - Zeiss Conquest 4.5-14x44mm - Brightest, no doubt about it.
2nd - Leupold LPS 2.5-10x45mm
3rd - Leupold VX3 2.5-8x32mm - Similar to IOR.
4th - IOR 3-18x42mm - Dimmest (Similar to the Leupold VX3).
If the 6X IORs are about the 5th best in light transmission then my comparison couldn't prove it. But they may rank highly against other equivalent scopes that also magnify over a 6X power range. My suspicion is that to achieve the 6X power range multiplication that additional lenses may be required. Each additional lens would cause additional loss of light to the eye.
With respect to resolution, we both rated these four scopes as follows:
1st - IOR 3-18x42mm - Notably the best
2nd - Zeiss Conquest 4.5-14x44mm - Pretty good - similar to Leupold LPS
3rd - Leupold LPS 2.5-10x45mm
4th - Leupold VX3 2.5-8x36mm
I later purchased a Sightron SIII, 6-24x50mm Mil-Dot reticle scope and completed another field comparison test. Same thing. Set up at a private gun range and zero each of the scopes on the 300 yd targets and trees at the end of the gun range an hour before dark, and continue to rotate from scope to scope to compare resolution and light transmission. Set all scopes to the same power, which would have been the highest power setting of the scope with the least power magnification. This post is dated March 3, 2009, so the vintage of the scopes were those manufactured prior to 2009.
http://www.longrangehunting.com/forums/f18/leupold-sightron-39643/index2.html#post266097
I believe I had sold the Leupold LPS scope by now. This test was completed to compare the better performing scopes from the prior testing, against my newly purchased Sightron SIII.
David, I was afraid someone would ask.
Here's an evaluation I recently conducted and reported for a LRH forum member .
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"Today I compared the SIII 6-24x50mm to a new IOR 3-18x42mm MP-8 and my Zeiss Conquest 4.5-14x44mm Mil-Dot scopes. I conducted an elevation turret test on all three scopes at 100 yds. Then I compared all three scopes for resolution and light transmission at 300 yds in the evening (fading) light. The SIII is hitting on all cylinders and I would rate it the best scope of the three - without regard to cost - provided you're content with that 6-24 power range. Based on cost it's obviously the best buy. Here's how I rated these three scopes. I own all three so there's no pride-of-ownership compromises involved in my evaluation.
Resolution.
1) IOR and SIII equally good at 18X. Then I turned the SIII up to 24X and it maintained excellent resolution and improved my ability to resolve details at 300 yds that I was unable to see at 18X through either the IOR or the SIII. In other words, I felt like I obtained the full benefit of the higher powers available in the SIII. Razor sharp.
2) Zeiss provided less resolution with all three scopes tuned to 14X at 300 yds. Still good, but not as sharp as the IOR and SIII.
Light transmission.
1) SIII - best
2) Zeiss - about midway between the SIII and the IOR.
3) IOR – I believe the IOR has some extra lenses in it to provide the 6X power range magnification, and every additional lens will reduce light transmission.
Weight.
1) Zeiss - 17.5 oz - 1" tube
2) SIII - 21.9 oz - 30mm tube
3) IOR - 28 oz - 35mm tube
Parallax Adjustment.
1) SIII - easiest to adjust, however the adjustment operates at a pretty fast rate.
2) IOR - just about as good as the SIII - operates at a slower rate than the SIII.
3) Zeiss - I've never really cared for the parallax adjustment on my Zeiss. It's OK but sometimes a struggle to know if it's set properly.
Crosshair/Reticle.
1) IOR - Best, I really like the IOR MP-8 reticle.
2) SIII and Zeiss - both standard military Mil-Dot.
Cost.
1) SIII ~$800
2) Zeiss~$850 w/o or $950 with target turrets
3) IOR ~$1565 w/illuminated reticle
Elevation Turret Test Results.
SIII: 0.273"/click/100yds in both the UP direction & DOWN direction over a distance of 26" at 100 yards. Same value/click/100yds in both the UP and DOWN directions, however different than the advertised 0.25"/click/100yds. This is why an elevation turret test is mandatory prior to putting any scope into action. Now that I know the IPHY click value, I'll be all set.
Zeiss: 0.243"/click/100yds in the UP direction over a distance of 26" and 36" at 100 yards. No DOWN test completed with Zeiss.
IOR: 0.260"/click/100yds in the DOWN direction over a distance of 26" at 100 yards.
0.250"/click/100yds in the UP direction over a distance of 26" at 100 yards.
The IOR yielded a different value per click per 100 yards in the UP direction versus the DOWN direction. My other IOR is dead nuts on - yielding 0.249"/click/100yds in both directions. This was a brand new IOR scope so I will have to conduct the elevation turret test again and make sure I didn't make a mistake with my calculations and determination.
[IN ORDER TO CLARIFY MY ELEVATION TURRET TESTS: All three scope's elevation turrets returned to zero properly. From a set Zero, I turned the turret in the UP direction and then returned back to zero. Then I turned the elevation turret in the DOWN direction followed by a return to zero. The IOR yielded a slightly different click value when turned in the DOWN direction than in the UP direction, however it and both of the other two scopes returned back to their zero setting correctly.]
I haven't shot the SIII yet but others have already confirmed the turrets are repeatable and that the scope is durable. The SIII has as good, or better, of a replacement warranty as the Zeiss or the IOR. If I were to buy another scope today, it would be another SIII 6-24x50mm Mil-Dot. Sightron is supposed to be adding some additional offerings to their SIII line. Whether there will be additional reticle options or power options, we'll have to wait and see. I understood they're expected to be out in the late summer-fall.
Hope this helps you spend your money wisely. For the money, the SIII is a best buy in my book." lightbulb
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The Vortex Viper is another scope that's at least as good as a Leupold VX-3 at a lesser cost, and the Vortex also includes a no fault lifetime warranty. You can run over the Vortex Viper with your GM (or Toyota) and return it for a replacement - no questions asked.
One year earlier I compared my Zeiss Conquest to my Leupold VX-3. The Zeiss Conquest smoked the Leupy in resolution and light transmission. It wasn't really even close. And I'm now telling you that the Sightron SIII bested the Zeiss Conquest in both categories in my recent side-by-side field comparison. The Sightron SIII is Sightron's top of the line scope. Comparing it to the SIs or SIIs is like comparing a Leupold Mark 4 to a Leupold VXII. The current limitations in the SIII series (my opinion) are the power range and the reticle options currently available. I'm led to believe some additional SIII options may become available later this year.
Leupold has made a good solid aiming device for many many years, which is why they still enjoy such a strong following. But there are currently a number of new players competing for their customers, and some are producing a better product with an equal warranty, at a lesser cost. Now I'm going to put my camo face paint back on and try to blend into the background noise...
I then purchased a second Sightron SIII 6-24x50mm scope. So I posted this on April 24, 2010.
http://www.longrangehunting.com/for...st-sightron-siii-55908/index2.html#post384772
I don't know if this is common amongst mid-priced scopes or not. I have read of similar experiences from other scope owners. Scopes of the same brand/model can perform a littler better or worse than other identical models.
I provided this head to head comparison of my Zeiss Conquest and Sightron SIII in a Post within another Thread more than 1 year ago. So prices may not reflect current prices.
[I'm referring to the March 3, 2009 Post - the one just prior to this quoted Post.]
I have since purchased another Sightron SIII. I have not conducted another head to head test with my 2nd SIII against the Zeiss Conquest. To be honest, I will say that my 2nd SIII is not quite as good optically as my original SIII. Still good but not quite as good. So I don't know if my 1st SIII was the creme of the crop, or if the 2nd SIII was sub-par. My 2nd one still performs very well in all respects, but the resolution and clarity of the glass is somewhat less than my original SIII.
Sorry. I know this throws the whole idea of SIII quality up in the air with question marks??? But I believe this is somewhat true of many makes and models of scopes. I've read this quite often with the Nightforce scopes over the past three years. Subtle differences in sight pictures between different scopes of the same model. Some have great glass. Some have good glass. I'll probably buy a 3rd SIII unless the feedback on the about-to-be-released Vortex Viper PST line of scopes is overwhelmingly outstanding and too hard to resist.
I've since purchased a 3rd Sightron SIII 6-24x50mm LRMOA scope. I have a strong bias towards lighter weight scopes, and these Sightron's weigh considerably less than the IORs, Nightforce, and Leupold Hubble. My hunting is almost entirely backpack hunting in the mountains, and I wrote off scopes weighing more than about 24 oz after having owned and packed two of the 28 oz IORs. Leupold's mid-prices scopes are on the lightweight side, which I appreciate. What I've observed is that as Leupold has attempted to provide higher quality glass (since 2010), the costs of those scopes with the higher quality glass has gone up substantially. As you've mentioned, it's tough competing with the foreign labor markets.
My head to head scope comparisons are now 4 to 7 years old. And all manufacturers' scopes continue to evolve over the years in order to maintain competitiveness. Some of the very same Leupold models I owned and tested back in 2007 and through 2009 may very well have better glass today. My testing of 4 to 7 yr old models may not be comparable to those same brands and model scopes today. I settled into Zeiss Conquest and Sightron SIIIs in mid-priced scopes, based on the scopes that were available at the time I needed some additional scopes for LRH. Scopes that I could afford and that were light enough for me not to cuss them out while packing them for miles in, up, and down, the mountains of Alaska.
For the Leupold loyalists, I used them for 25 years and still own a couple 2.5-8x variables. I've migrated to the brand and model scopes that best suite my current LRH needs, within the constraints of my income and budget. Lighter weight is a large consideration, and Leupolds provided that. So the primary reason I'm not currently using them is the price premium to obtain similar quality resolution and light transmission. I should also mention I hunt sheep every year and sometimes rely on my rifle scope to judge horn length and count growth rings on the horns. I place a high priority on a resolution of the glass at high magnification power settings. In decent light conditions, my SIIIs provide equally good resolution as IOR scopes that cost much more money.
