IS on and off

Some weeks ago, we had a discussion going about shooting long focal lengths with IS on and IS off. I was planning to do some experiements, but my camera was in the shop, then the ice storm. Instead of trying to find that old thread, I'll just start a new one.
I just did a number of test with my 200mm f/2.8 of a distant subject comparing handheld with IS on and tripod with IS off (I was also testing to be sure AF was accurate at infinity).
To my surprise, the images with IS on (handheld) were sharper than those from a tripod with IS off.
All shots were with a Pentax K20D (in camera IS) in good, strong light, progam P, a little over 1/600, same f-stop, ISO 100. At normal view, they both looked the same, but when I magnified them 10 clicks on Infranview full screen, those with IS on were noticably better. I actually expected the opposite.
I also tested the same way with ISO set at 800 (1/2000, f/10) to also check for noise difference. The results for IS on and IS off were the same, and I could tell no difference in noise levels.

It's difficult to make a direct comparison (I know, I've tried :p ).

What tripod is "equivalent" for testing purposes? How steady are you naturally?

I think each person needs to perform his/her own tests using their own equipment (including the tripod normally used) to see how the IS stacks up on an individual basis. I know that, for me, my 4 IS lenses either handheld or on a monopod is good enough for a majority of my shooting.

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Originally Posted by Ron Kruger

I also tested the same way with ISO set at 800 (1/2000, f/10) to also check for noise difference. The results for IS on and IS off were the same, and I could tell no difference in noise levels.

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Noise wouldn't change at the same ISO.

I'm curious if you used a cable release or the self timer on the tripod shots? For me, I always try to use a cable release if possible when shooting on my tripod. With wildlife, that isn't always possible though. If the critter is moving, I have my ballhead loose, so I can track the subject, and use the tripod as a pivot point. I don't have any IS lenses yet, so trying to find the best technique is key for me.

Sorry, Loupey, I wasn't very clear. In addition to testing hand-held (IS on) and tripod (IS off) at the same settings, I tested the same way at two different ISO settings to check for noise (which also affects clarity) between the hand-held and tripod shots taken at 100 and 800 ISO--not at the same ISO.
I'm pretty steady off-hand, but I doubt I'm as steady as even a cheap tripod, so I came away from this very confident in my Pentax's in-camera IS.

No, MJS, I didn't use a cable release. I don't even have one, because I found it impractical for field work. While there is a possibility that I caused some camera shake on my cheap tripod when I pressed the shutter release, I'm pretty smooth and careful about it.
As I mentioned, the difference wasn't noticable until I magnified the images 10 times, but the results were opposite of what I had expected.
Now you've got me wondering if I mixed them up, so I'll do it again for conformation.

Leave it on if you want to. Many people do with no harm to image quality noticed. Mine is on. But Nikon says mine can be on even on tripod :)

I did the experiment again--same results.
I did notice some difference, however, in saturation and hue between IS on and IS off. What's up with that?

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Originally Posted by Ron Kruger

I did the experiment again--same results.
I did notice some difference, however, in saturation and hue between IS on and IS off. What's up with that?

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Never heard of it, never happened to me or people I know. Have you talked to other Pentax users?

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Originally Posted by Ron Kruger

I did the experiment again--same results.
I did notice some difference, however, in saturation and hue between IS on and IS off. What's up with that?

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Could it be a white balance issue? If your camera is set to Auto WB, it could have changed between shots?

Well, the thing that caused me to investigate this IS on or off thing in the first place, is that I noticed a slightly different look in exposures. It's not a great difference and requires a pretty critical eye. I wasn't sure what it was at first, but I'm fairly certain now it is not noise or clarity, but saturation and hue.
It's a consistent difference I've noticed between various shots taken under the same lighting with the same settings, except IS on and off. I imagine you're right about Auto WB, Mike, but I don't think it is a difference in lighting conditions between shots, but some effect IS on and off is having upon the WB reading.

Hi Ron,
Could you post an example? Or would the compression to jpeg and resizing skew the results?


Not to change the topic of your thread.
I would love to see some results from your ISO 100/800 experiments. Are you post your results on that experiment?
What exactly do you look for when comparing the two photos? Is it just how black [no noise] the black parts of the photo are?

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Originally Posted by Ron Kruger

I imagine you're right about Auto WB, Mike, but I don't think it is a difference in lighting conditions between shots, but some effect IS on and off is having upon the WB reading.

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With auto WB, the lighting doesn't have to change at all for the camera to change the WB setting. This is reason I don't use Auto WB.

First to answer some replies, then I'll post the results from my recent tests.
Bob: My tests are for my camera (K20D), and I'm suspect results may vary between brands and even models of the same brand, so I suggest everyone conduct similar tests. I shot all the test images in RAW/JPEG, using exactly the same scene, and saw no appreciable differences between RAW and JPEG images in my camera's computer software imaging program or on Infranview. Besides, I've already deleted the test results, after considerable study and making notes. Maybe later, I'll take the time to shoot some more and process them and post them here, but I have some writing deadlines dogging me now.
The results of the ISO experiements are posted in the Pentax thread, because they are even more specific to the K20D.
MSJ: Because all of my serious shooting is done under the constantly changeing conditions of the outdoors, and because most of my shooting is during spur-of-the-moment situations, I don't have time to shoot test images, study histograms and such such, so I must rely on Auto WB. My subjects move a lot, and none of them want to be famous. Besides, I don't feel I know enough about it to override the auto function.

I understand where you're coming from Ron. I don't mess around with WB in the field either. I set mine on daylight, and leave it there. If I need to change it, it's a simple click of a button in my RAW converter. The reason I brought it up was because it could be the cause of the differences you are seeing. If you do another test, you should be able to check the color temperature in your RAW converter to see if they are exactly the same.

I believe the difference in saturation and hue that I'm seeing between the IS settings has to do with how the auto-exposure is reading when the IS is on and when it is off. I have no idea why, but with the same shots, of the same subject, distance, framing and ISO settings (100), I got 640th sec at F7.1 with IS off and 500th sec at F/5.6 with it off. So I did it again, thinking maybe the light changed between shots (a matter of a few seconds). On the second test I got 500th at F/5.0 with IS off and 400th at F/5.0 with it on.
Now, while this proves the light was changing because of the different exposures between tests at the same IS setting, it does indicated that the readings were varying each time between IS on and IS off.
So I believe the saturation and hue are the same regardless the settings, but the degree of that saturation/hue varies according to the f-stop/shutter speed relationship, which for some reason that eludes me is changing between IS on and IS off. As a general rule, exposures toward the darker side are going to have more saturation (and more dramatic hues), while those on the brighter side have less.These exposure parameters can be controlled by underexposing by -1/3 or over exposing by +1/3 as needed, or by auto-bracketing shots and then picking the one with the perfect exposure/saturation/hue. (Exposure, of course, can also be altered in PP software to get the same thing, but my attitude is to get the best possible shot from the camera and do as little in PP as possible to maintain the integrity of the image, especially with JPEGs.)
As I mentioned above, I shot all the test images in RAW/JPEG, and saw no appreciable differences between RAW and JPEG images in my camera's computer software imaging program or on Infranview.

Generally speaking, I'm getting a slightly darker exposure with IS off than with IS on, and this is why those shots appear to have more saturation and a slightly richer texture, which I actually prefer for images I submit for publication.
The tests I just conducted re-confirm that general image sharpness is better with IS on than with it off and on my tripod. (This time, I might add, I set my camera on mirror-up, 2 sec delay for tripod shots to cut down on possible mirror slap and shake during exposure.) I will admit, however, that my tripod is a WalMart bargain and no were near professional quality.
That’s because I find a tripod impractical for the kind of wildlife photography I do and use a good monopod instead. Most of the time, however, I hand-hold my 200mm F/2.8 for shooting critters.
While my experiments have answered some questions about IS, and have given me some clues to getting the perfect exposure with it either on or off; and while it has renewed my faith in my K20Ds in-camera IS technology, this does raise the puzzling question of why the exposure meter is reading slightly differently between IS on and IS off?

Ah, now things make a little more sense for me. A slightly different exposure would have an effect on the colors. I didn't know you were using AE. My guess is that is the reason you are getting slightly different exposure settings. There is no way that you are going to be able to frame the same image exactly by hand holding do to movement. It wouldn't take much movement to introduce a little more highlight, or shadow into the frame when you move to turn the is on or off. Depending on the metering mode, this difference could be quite large.

If you have time, and want to dig deeper into this, I would test in manual mode, so you know that your exposure isn't going to change at all. Eliminate as many variables as you can. Tripod, manual exposure, manual focus, manual WB etc. I like to do my testing in doors, with a subject that isn't going to move, and lighting that I know isn't going to change. Of course this isn't going be the same way you will be shooting in the field, but it may help you get to the bottom of your questions.

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Originally Posted by Ron Kruger

First to answer some replies, then I'll post the results from my recent tests.
Bob: My tests are for my camera (K20D), and I'm suspect results may vary between brands and even models of the same brand, so I suggest everyone conduct similar tests.

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I hope I am not hyjacking your thread...I don't mean to be...your test just sound so interesting.
Being new to digital slr's I seem to go out shooting with my camera set to different parameters everytime.
I have come back with all orange photos, photos over exposed/underexposed, out of focus, blotchy everything.
Thank God I did not buy this camera and go on a world tour...
I decided I need to just go out in the backyard with a detailed plan to get these setting figured out.

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I shot all the test images in RAW/JPEG, using exactly the same scene, and saw no appreciable differences between RAW and JPEG images in my camera's computer software imaging program or on Infranview.

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Interesting, I can usually see a slight difference, mostly in the hues of the shadows if I put the photos up side by side. It might be worth checking your control panel color depth. When my daughter plays a game on my computer it sometimes switches the monitor color depth to 256 colors (8bit) I'm always checking that it's in 32million colors.

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Besides, I've already deleted the test results, after considerable study and making notes. Maybe later, I'll take the time to shoot some more and process them and post them here, but I have some writing deadlines dogging me now.

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I understand, sorry if I put you on the spot.

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The results of the ISO experiements are posted in the Pentax thread, because they are even more specific to the K20D.

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Thanks, I can't wait to try this test as well.

MSJ: Those are excellent suggestions. I realize a controlled experiement in the outdoors is not cont completely controlled, but that is where I live with my camera, so although my results are open to scientific speculation, all I intend to draw from them is general principles that I can apply to actual field work.
Indoor and studio photography is a whole other world, and I think the results I would get with artifical lighting would not be as applicable to outdoor lighting, and that's where I do everything since my wife won't pose nude for me anymore.
I do, however, want to dig deeper into this and will take your suggestion for more controlled exposures and such at a later date.

FSJ: During my tests, I'm using my 200mm F/2.8 and shooting the front porch of my neighbors house about 1/8 mile away. I'm setting the camera for tripod shots first and putting the exact center of the frame upon his front door. As soon as the shot snaps, I'm grabbing the camera from the tripod, switching IS and taking the IS on shot from the same spot as quickly as possible, but being sure to again center the frame upon his front door.
Given the focal length and the controlled framing, I doubt the exposure would change between shots as it might if I was using a closer subject or a slightly different framing.

Bob: I certainly not new to photography, but am fairly new to digital, so I'm on a learning curve too.
This is my slow time. I've often said the only good thing about February is it only has 28 days. So it is when I conduct various experiments, test lenses and such to learn things that will help me in the field throughout the rest of the year.
You didn't put me on the spot. I believe, based upon MSJs suggestions, that I'll be conducting further, more controlled tests, and I'll post some shots here next time. I probably should have thought of doing that in the first place, because someone may notice something I'm missing.
I have calabrated my screen and set it to load those paramaters each them the computer is turned on, so I think what I'm getting in my camera is what I'm seeing on screen.
And I sincerely hope more people try these tests so we can compare different makes and models, especially those shooting in-lens IS.
The differences between those technologies posed in posts here a couple of months ago is what prompted my investigation about IS in the first place.

I am, by the way, shooting everything in aRGB these days. Even though that is a different color space than sRGB, for comparision purposes, I can't imagine how it would make any difference from one shot to the next, all shot in aRGB.

Another by the way:
I belong to Pentax's Professional Program and have asked one of there Product Specialists to check out these threads and comment, maybe offer some insights--especially about the exposure differences I've noticed with IS on and off.
You know, these guys are pretty clever about designing these products for people who don't know nearly as much about photography as they, and modern cameras are like a computer in your hands. It could be that they realized when someone was shooting with IS off, they would benefit from a 1/3 bump in exposre (slightly higher shutter speed), or when they turned it on, they could get by with a little slower shutter speed and more saturation.
It might be built into the firmware to benefit rubes like us without even knowing it.
I don't know. Just a thought.

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Originally Posted by Ron Kruger

... I got 640th sec at F7.1 with IS off and 500th sec at F/5.6 with it off. So I did it again, thinking maybe the light changed between shots (a matter of a few seconds). On the second test I got 500th at F/5.0 with IS off and 400th at F/5.0 with it on.
...

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This defeats the original purpose of your test (comparing IS/handheld verses non-IS/tripod). Whenever you test anything, you always leave everything that you're not testing unchanged so as not to introduce any variables into the test (which you got).

I see a lot of confusion in this thread. First off, Image Stabilization has absolutely nothing to do with image hue, saturation, or noise. None. It is nothing more than a mechanical counter-movement device that either moves the lens elements (Canon/Nikon), or the sensor (Olympus/Pentax) to compensate for movement in the opposite direction. It's really no more complicated than that. It typically uses a small gyroscopic sensor to tell the camera to adjust the lens element angle or sensor opposite the perceived movement. that's all.

I think the conversation a while back may have come from a statement I made about turning off IS at extreme focal lengths when shooting from a good tripod or rest. The reasoning behind this is that at extreme focal lengths EVERY movement is amplified....even that of the IS mechanism. What was happening to me (typically at focal lengths of 1000mm or more) is that a very slight movement (like pressing the shutter) would cause IS to activate. that would in turn adjust the element in the lens, which would then move the highly magnified single point of focus off target. This would then cause the camera's auto focus to go into "hunting" mode. If you're lucky, 15-20 seconds later you'd be back on target! The best remedy was to simply shut off IS, and thus significantly reduce the lens from going into focus hunt mode.

I think it's a completely irrelevant discussion at focal lengths that are sub 500mm. ANYTHING that is hand held will benefit from IS. Nobody is THAT steady....I don't care how much they brag about how steady handed they are. People wobble (but they don't fall down....sorry....just had a "Weebles" moment there). I don't think I've ever turned it off on my intermediate telephotos.

Now, with all that long winded garbage I just typed.....Canon has just released an incredibel 4 stop IS system with thier new 800mm f/5.6 lens. I stood next to Artie Morris on Saturday morning in dense fog, and watched him nailing shots with a 1.6 CF camera (the 50D) on the 800mm f/5.6....giving him an effective FL of 1280mm...and shooting at 1/30th of a second!!!!!! That system is incredible. If I try that with my 600, all I get are artistic blurs :lol: :lol:

I doubt there is the same effect in IS lens technology, but I am seeing a difference in IS in-camera technology. They may both be trying to accomplish the same thing, but they are doing it from different angles and with different technologies.
Something is happening to saturation and hue between IS on and IS off, and I believe it is due to slightly different (about 1/3-stop or so) auto-exposure readings between IS off and IS on.
I may be confused, as you suggest, or stupid, as Loupey suggests, but something is going on.
I didn't start taking photos yesterday.

Listen, you guys rule the roost here, so if I'm stepping on your attention toes, I'll bow out.

This is a very interesting thread, and I too, am interested in your tests Ron.

Though it is getting quite confusing here. And no, I don't think your stupid (Loupey probably didn't mean that), it is great to hear other people's opinions and experiences with the IS-systems, especially since I use PENTAX too.

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Originally Posted by Canon_Bob

Now, with all that long winded garbage I just typed.....Canon has just released an incredibel 4 stop IS system with thier new 800mm f/5.6 lens. I stood next to Artie Morris on Saturday morning in dense fog, and watched him nailing shots with a 1.6 CF camera (the 50D) on the 800mm f/5.6....giving him an effective FL of 1280mm...and shooting at 1/30th of a second!!!!!! That system is incredible. If I try that with my 600, all I get are artistic blurs :lol; :lol:

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How about the Canon 200mm F2.0L IS lens...? 5-stop IS with auto tripod detection. Olympus E-3 also has 5-stop in-body IS.

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Originally Posted by Ron Kruger

Listen, you guys rule the roost here, so if I'm stepping on your attention toes, I'll bow out.

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Hey Ron, I don't think anyone's trying to offend here. I know I certainly don't want anyone to "bow out". You may have uncovered a flaw in Pentax's IS system.

From my point of view, I don't want the concept of IS being a bad thing being put out there based on isolated or inaccurate results. There are a lot of folks here who are newbies, and if they get the idea that IS is a bad thing, and turn it off because someone in a forum said it affected hue, saturation, and noise in their camera.....well.....I can't really sit back and ignore that. Perhaps Pentax has a flawed system if you're seeing it, but I guarantee you that Canon and Nikon do not have that issue. To me, IS is one of the best inventions in photography ever. And it's improving more and more. There are isolated instances where it may be counter productive, but the goods outweigh the bads BY FAR.

I suggest you lock your camera in manual mode, and redo your tests with the same manual settings in both IS on and IS off modes. Use the same subject, same light, and post the unmodified pics with Exif intact. THEN I'll buy that hue, saturation, and noise are affected in your camera with IS on or off.

You'll have to excuse me if I seem like I'm coming on a bit strong here, but I'm an Engineer by trade....so I always ask questions when things like this are presented. I am having trouble understanding how a purely mechanical function that has no bearing on exposure settings can have an effect on color and noise level. That's all.

Again, there is absolutely no intention of offending here. You may well be onto something that is either Pentax or "in camera" IS specific.

-CB

This is a very interesting thread. I believe you and I both use Pentax K20s Ron. I'd be happy to set it up indoors and run some shots to test this effect. It might be interesting to see if my camera does it as well. Any suggestions on settings?

i agree with what others have said, this is an interesting subject, but as a scientist ( or at least trained to be one) the ONLY way to do a comparative test like this is to keep EVERY setting the exact same EXCEPT the one you are testing. that means manual exposure, manual focus, manual WB, everything except the VR switch and tripod. but think of it this way... with a camera it is REALLY EASY to do this. most experiments its impossible to keep everything but what your looking at the same. and thus you should get really definitive results.

The noise thing is a whole other issue, related to ISO, not IS. And I'm not suggesting in any way that Pentax has "a flawed system." Quite the contrary: My results with IS on were better than those with a tripod and IS off.
In fact, listening to you Canonites, I was beginning to think I made a mistake switching from Nikon film to Pentax digital, instead of sticking with Nikon or switching to Canon or Sony. I don't tend to think that just because it is the camera I chose, it must be the best.
The thing is, both the IS and ISO experiments I've conducted under actual working environment conditions have reinforced that I've made a good decision switching to Pentax and renewed my confidence in the equipment--not the other way around.
These experiments, though maybe not as scientific as some would like, are very practical for my real world applications, in the field, where I make part of my living. I've sold five magazine covers since getting this Pentax last June. That alone should speak well for Pentax quality.
If I switch everything to manual, and shot indoors under closely controlled lighting conditions, would I see the same (slight) differences in exposure values? Probably not. But what would that prove to me for practical applications? Nothing. That's not the way I shoot in the field, nor is it practical to even think of shooting that way in the field.
So you all can take my experiments and finding for what they're worth to you, and for any beginners out there who also misinterpeted what I was trying to say in an objective way--generally IS is better on than off, and is the greatest part of modern digital technology.
Also, beginners should be aware that what I noticed in exposure values were very slight and that I look at all this with a very critical eye toward professional quality beynd what would matter to most.
Nor do I think that my experiments are conclusive in any way. There are so many variable in photography, and there can be differences in equipment, even between copies of the same model. That's why I've suggested that other conduct their own experiments with their own equipment.
So I'm not scientifically ignorant here, either. I'm just trying to be practical for my own business purposes.
At any rate, I think I'll leave all the important stuff to the important people in the future.
Digital Photography Review has a bunch of working professionals and includes the guy who has written over five books about photography and the business of selling images, plus I got to know Pentax's head of product development over there.
There's a bunch of great people here, too, and I've learned a lot. Maybe I'll hook up with some of them later.

Sorry you're feeling offended Ron. That was certainly never my intent. I would've been interested in seeing your next wave of tests.

I consider myself completely agnostic anymore when it comes to manufacturer. When I bought my gear, I researched who was the best at the time. It was Canon....Hands down. Now I'm into that system for more than 15k in glass alone....so switching is highly unlikely unless one of the competitors makes a SERIOUSLY significant advancement. In fact, there's a reason I'm still shooting a 1DsMII Canon instead of the Mark III. The reports of the Mark III focusing problems caused me to decide to skip a generation!

That said, if I were buying today...It'd probably be Nikon. They have (IMO) leapfrogged Canon for the time being. I expect Canon will jump ahead again very soon. The dark horse to watch, IMO, is Sony. They have made moves to position themselves right at the top. I expect they will pretty soon. I don't know a thing about Pentax or Olympus. They may be great for all I know. At the end of the day the fact remains that the photographer has a heck of a lot more to do with the resulting image than the camera does.

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Originally Posted by Dylan8i

i agree with what others have said, this is an interesting subject, but as a scientist ( or at least trained to be one) the ONLY way to do a comparative test like this is to keep EVERY setting the exact same EXCEPT the one you are testing. that means manual exposure, manual focus, manual WB, everything except the VR switch and tripod.

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But if the tests so far seem to suggest that the in-camera IS system of Pentax may be affecting the performance of the in-camera exposure meter, giving different readings depending on if IS is on or off, then leaving the exposure mode to auto seems to be the right way to go for additional testings.

Then again, by using manual exposure mode, and the test results still give us two differently exposed photos, then it's something else that the IS is affecting, I suppose, assuming IS itself does not - I believe - affect exposure at all.

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Originally Posted by AgingEyes

But if the tests so far seem to suggest that the in-camera IS system of Pentax may be affecting the performance of the in-camera exposure meter, giving different readings depending on if IS is on or off, then leaving the exposure mode to auto seems to be the right way to go for additional testings.

Then again, by using manual exposure mode, and the test results still give us two differently exposed photos, then it's something else that the IS is affecting, I suppose, assuming IS itself does not - I believe - affect exposure at all.

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Exactly. the only way to prove this out is to lock out all other variables except IS and then tripod. If the IS on created diffent exposures than IS off under those conditions, then a case can be made for light angle caused exposure variances against the sensor (which is moved on most in-body IS systems). You'd also want to test this in very stable lighting conditions.

Any other testing conditions would quickly cause any conclusions surrounding hue/saturation to be a product of changing light/and or auto exposure setting changes. IS would quickly be dismissed as a possible cause for the variance.

yep first you would need need to isolate the IS function itself to see any differences. then you can move out to using AE under controlled lighting to simulate the field useage that Ron wants to test.

if there is a difference when only IS/tripod is changed then you know thats whats causing it. if there is no difference when just IS/tripod is changed (think of it as a control) but there is one when AE is on and IS/tripod is changed, then you can say that the AE programing is changing something when the IS switch is flipped. THEN you can worry about having to compensate for it one way or another.

I don't think the tripod test will show any difference for the nikon users with a VR lens. The Lens manual states it detects panning and activates IS. So on a Tripod VR on or off should result in an identical photo.

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VR
Vibration Reduction (VR)
This innovative VR system minimizes image blur caused by camera shake, and offers the equivalent of shooting at a shutter speed three stops (eight times) faster.* It allows handheld shooting at dusk, at night, and even in poorly lit interiors. The lens’ VR system also detects automatically when the photographer pans — no special mode is required.
* As determined by Nikon performance tests.

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As I was shooting some indoor shots with a home-made lightbox I shot these jellybeans as a test for this thread. They were shot with the Pentax K20d in all manual mode, at F22, 1/15 second, 400iso, and 200mm. Using a Tamron 28-200mm zoom. The camera was on a tripod for these of course, tripped with a wireless remote and the only change made was to shoot one with SR on and one with it off. No photoshop was done other than to downsize and convert to jpg.

Here is SR on...

http://members.shaw.ca/stillwtrs/sr-on.jpg

And SR off

http://members.shaw.ca/stillwtrs/no-sr.jpg

Hope this helps, although I may be missing something in the discussion that makes this test irrelevant. I do believe I see a loss in the saturation of colours with the SR on, it's very slight but I don't believe I'm imagining it. Actually with the SR off the entire shot seems just slightly lighter. Actually with the SR off the lighting in the shot seems just a fraction brighter.

Interesting. When I first looked at these online, I thought I could see a slight difference. I downloaded both of these images and put them into a single layered file in PS and made them registered exactly the same. When I turn one layer off, I do notice a very slight change, but from what I can tell, it's the noise moving around.

So then I took the color sampler tool, and selected an area using the 11x11 pixel average. When I would check the RGB numbers between the two layers, checking the exact same spot, there was a slight difference. For example, one went from R-171 G-97 B-58 to R-171 G-97 B-56. This could be caused by some different colored noise moving into the selected area but I don't know for sure.

the with out does look lighter to me to. especially in the jelly bean shadows.

Well, by golllly. That's what I've been talking about.
If you will put the two images so you can see the bottom beans at the same time, you'll notice a slightly darker cast to the whole scene and more color saturation in the beans--all colors. That's what I've noticed during field work. It's not saturaton actually, but slightly different exposure values, and you naturally get the look of more saturation with a darker exposure. I often underexpose my shots by -1/3 to get that, because it's better for publication purposes.
In-camera metering systems are very good these day, but they are designed for the average guy who wants to print nothing larger than 8X10s or post them on the internet, both of which use an sRGB color space. Commercial printing uses a larger and more sophisticated color space of aRGB, but even with my camera set at aRGB, the "perfect" exposure is designed for computer screens and cheaper (relatively speaking) printers and just a tad too bright for printing. So I often underexpose shots to get those richer colors for printing.
I shoot differently than most, because I shoot with the printed page in mind, and printing (especially ink absorbstion of paper) robs images of some color saturation and contrast, so I bump them slightly to get the kind of "magic" I used to get from underexposing Kodachrome 25 back in the day.
We're not talking about a big difference in the shots here or what I got in the field--less than -1/3--but I've been doing this for over 30 years and spend a lot of time looking critically at images. I knew I was onto something.
I still have no idea what's causing it, and it really isn't a big deal, but I'd like to see some similar tests conducted with Canon and IS lenses.