[rogerstg]

It won't get better than 6.3 stops. That is unless you can slow the earth rotation.

It seems that all you need is the ability for the camera to know where it is and which direction it is pointed for software to account for the earth's rotation.

Probably need more processing power than currently available, but it would be easier than slowing the earth's rotation.

[Fogel70]

The whole 8 stops of IBIS seems over inflated. If you are shooting a 24-70 lens at 40mm, it feels like even with stabilization that is great, it would be a struggle to hand hold at 6 or 7 seconds, which is what that would be. My experience with Pentax is that IBIS works well till you get to shutter speeds that are slower than 1/2 second and then it doesn't matter what the focal length is, I can't really hand hold it. So, I can hand hold 60mm at 1/6 second and get sharp images, but at 15mm I can only hand hold to about 1/4 second before shake starts to show up.

In a test rig it probably works well, but in the hands of a human the camera shake is probably much more complex with multiple variable frequency and amplitude overlayed on top of each other, which is difficult for the algorithm to predict.

But it is a standardized test rig with 2-axis camera shake that is used for verifying the capacity of image stabilization, so the ratings can easily get over inflated.

[Mooncatt]

But it is a standardized test rig with 2-axis camera shake that is used for verifying the capacity of image stabilization, so the ratings can easily get over inflated.

Lab tests are fine for comparisons, but I don't put a lot of faith in them for just that reason. It's too easy to get caught up in the specs and forget real world variables.

[rogerstg]

Lab tests are fine for comparisons, but I don't put a lot of faith in them for just that reason. It's too easy to get caught up in the specs and forget real world variables.

Yes, like subject movement

[Des]

For those of you who have used the older cameras as well as the latest generations of Pentax gear, have you noticed improvements in the effectiveness of the IBIS systems? A more effective IBIS system and better AF in the k-new would almost clinch a purchase from me.

I've had a K100D super, K-30, K-3, K-S2 and KP. There are obvious improvements in each generation. The KP is a leap ahead of the K-3 or K-S2 (each of which is good) - great for when a tripod isn't available or practical. Here's one at 0.8 seconds.

I have "nervous hands," and my recent freehand use of longer focal lengths has been a challenge.

You are not alone in this - it seems to be a common story. As @BigMackCam said, working on technique can help mitigate the effects. I have found this excellent article really helpful: Making the Most of Long Exposure Handhelds - Introduction - In-Depth Articles

[Password1234]

One thing to keep in mind is that every time the pixel count goes up, the pixel shift impact is more substantial. Even if the performance where to stay the same it would mean an improvement in effectiveness/precision.

[vonBaloney]

One thing to keep in mind is that every time the pixel count goes up, the pixel shift impact is more substantial. Even if the performance where to stay the same it would mean an improvement in effectiveness/precision.

Pixel shift or IBIS? IBIS would have to get better with more pixels on the same size sensor, right?

[Password1234]

Oh sorry I was talking about Sensor shift but wrote pixel shift. But yes it need to improve the more pixel there is on the sensor.

[vonBaloney]

Oh sorry I was talking about Sensor shift but wrote pixel shift. But yes it need to improve the more pixel there is on the sensor.

Oh, I see, I thought you were saying the opposite, but you were saying IBIS *must* improve just to keep the same performance as the pixel density goes up.

[zapp]

Looks like an old thread, but I think it is still relevant. More and more manufacturers include some kind of ibis and optical lens stabilization in their cameras. Pentaxians know that SR works with all lenses, but there is more than a simple number game going on. Most manufacturers claim a CIPA rating only for one or two lenses, some do better for more lenses if you dig deeper.
Results are scaled by pixel pitch. Nikon Zf performs better than Z8 because of wider pixel pitch. The real story starts with long glass. Here shutter/mirror vibration are more important. Rating a long lens stabilization as being 6EV better than without is something. It would be really nice to see more numbers here for different lenses. OM 150-400 has a great rating, but valid for 150mm. The 100-400 performs “worse”. Does Pentax 150-450 really benefit from 5(.5) stop advantage of K1/3 cameras? Sony publishes values for the 1.2/50…
Think a little deeper and it makes perfect sense even for Pentax to work on shake reduction for all lenses. Plus you get all the advantages (and some disadvantages) of a stabilized lens. The internet only discusses numbers and makes silly comparisons. Real values are missing.
Yes, you still need to make your own tests, but manufacturers are not making up numbers, they just do not present all the numbers.

[HoundFrog]

Pentax lost the big game and is reducing itself to a "niche". I would not expect any breakthroughs.

About the 150-450, I use it with K-1 and even the 1/f rule is not enough sometimes. For critical shots where I need full resolution I use tripod and electronic shutter if possible.

[Lowell Goudge]

As I have used Pentax since the inception of digital (and 25 years prior to that on film) and had a ton of old glass I had lots of opportunities to try out IBIS. What I find overall is the following, all of which are my opinion based on use and not scientifically measured.

Starting with the K10D over the *istD I found IBIS did provide 2-3 stops improvement, and this was especially true using shorter focal lengths in low light. I found for longer focal lengths, it was not as effective.

Moving to the K7, I started to notice improved performance with tele lenses, and even posted one shot here of a night heron, taken at 1/40th with a K300/4 on the 1.7x AF converter, I will admit, however, this was probably the best shot I ever took, relying totally on shake reduction, as 1/40 with a 500 mm lens on a crop sensor totally defies the 1/(F x crop factor) rule of thumb which would be 1/750 minimum shutter speed, as it is about 5 stops better. I believe several things helped this shot.
- My technique, with my eye against the viewfinder, one hand on the grip and shutter release, one hand on the lens hood, as far away as possible, stance of feet apart and right leg stepped back about 1 foot, and elbows tight on the body I.e. the classic recommended technique
- the lens, not that the K300/4 is a great lens, in fact I think it is rather average, but at 1040 grams it is relatively light, and compact, especially when combined with the 1.7x converter. 500mm at 1.2 kilos is REALLY LIGHT and the center of gravity is not that far away from the camera itself
- finally, and obviously there were improvements in IBIS between the K10 and K7.

For a long time after this I fell away from relying on IBIS because my main lens for birding was a sigma APO 70-200/2.8 EX and Sigma APO2x EX DG Teleconverter and none of the bodies would allow modification for use of a TC to modify the SR focal length. This was, IMO a mistake by Pentax because they didn’t make a TC themselves, Didn’t for years have an offering of their own beyond 300 mm yet would not accommodate users (and customers) who sought 3rd party solutions for failings in their line up.

The other thing I noticed, and this was with the IBIS implemented in the Q, is that it seemed to be over active, especially with longer lenses, and in many instances I found the best stabilization was at about 2/3 the actual focal length. Where I am heading with this observation links into some of the old observations in this thread, where some manufacturers are claiming greater improvements with some lenses over the general capabilities. This is specifically based on how IBIS has to work.

Regardless of who makes it, or how many sensors, in a camera, all the accelerometers are very close to the focal plane. They have to be because a DSLR is , except for mirror box and grip, about 25mm thick, and a mirrorless, or a small format camera like the Q is substantially less. Therefore to calculate how much compensation is needed, and considering that any movement is most likely in the form of a rotation of a free body about its center of mass, the IBIS really needs to know. Where the center of mass is, for each and every lens, and the range of movement during focusing from min focus to infinity. Without this data, IBIS tuning can ever only be approximate, and would likely support shorter focal lengths over longer ones, and lighter lenses over heavier ones. In fact, this last point could probably be tested easily. I have two lens candidates, to propose the test, my tamron 28-75/2.8 and my sigma 70-200/2.8. Using both lenses at 70-75mm and varying amounts of “need” from the shake reduction, could with enough samples demonstrate the pros and cons of each lens, and how the body manages shake reduction.


The other thing I note in a lot of the old discussion is moving to a formula based on sensor resolution. This is perhaps an incorrect approach. You need to go back to the film era, to get to the root of a lot of rules, specifically with respect to the definition of acceptably sharp.

The definition of acceptably sharp, was that a point of light, would be no larger than 1/100 of an inch when a negative was printed on an 8 x 10 paper. This led to the definition of circles of confusion of .03 mm for Full frame and .02 mm for APS C sensors.

Now consider the resolution of the sensor. A K1 for example has a pixel pitch of 4.9 microns and therefore there a 30 micron spot will span a little over 6 pixels doubling the resolution will make the same spot 12 pixels, but it won’t change at all the size of the spot when printed to 8 x 10. So the only way to gain a claimed improvement in SR performance as a function of resolution is to enlarge further and redefine the circle of confusion.

[HoundFrog]

The definition of acceptably sharp, was that a point of light, would be no larger than 1/100 of an inch when a negative was printed on an 8 x 10 paper.,

I disagree. First if all, that's a pretty old definiton, and it was based on old tech limitations. Everybody zooms now, we need to accept that. And the old artists, when they were creating those huge 6'x8'-ish oil paintings, they did care about tiny details smaller than a match head. More like 10-4 criteria instead of 10-3 you quoted.

Second, the motion blur is very different from Gaussian blur. Motion artifacts are much more visible to an eye. So the criteria for the "shake" artifacts should be even stronger.

[Wheatfield]

I disagree. First if all, that's a pretty old definiton, and it was based on old tech limitations. Everybody zooms now, we need to accept that. And the old artists, when they were creating those huge 6'x8'-ish oil paintings, they did care about tiny details smaller than a match head. More like 10-4 criteria instead of 10-3 you quoted.

Second, the motion blur is very different from Gaussian blur. Motion artifacts are much more visible to an eye. So the criteria for the "shake" artifacts should be even stronger.

That old definition comes from what the human eye can resolve. Our eyes haven't changed all that much in the past 100 years or so.
As for has shake reduction become more effective, yes it has, but it has also had to to keep up with increased pixel density.
Even with shake reduction, I need to be a lot more aware of technique with my 40mp APS-C camera than I do with my 36mp full frame camera.
Shake reduction is reactive technology, not proactive. For it to be effective it has to react faster and more accurately as sensor counts increase since camera movement as slight as 1 pixel will show up as camera shake.

[Lowell Goudge]

I disagree. First if all, that's a pretty old definiton, and it was based on old tech limitations. Everybody zooms now, we need to accept that. And the old artists, when they were creating those huge 6'x8'-ish oil paintings, they did care about tiny details smaller than a match head. More like 10-4 criteria instead of 10-3 you quoted.

Second, the motion blur is very different from Gaussian blur. Motion artifacts are much more visible to an eye. So the criteria for the "shake" artifacts should be even stronger.

But the criteria, of a point being acceptably sharp for an 8x10 print viewed at a normal distance is what was used for the old rule of thumb for motion blur and all calculates backward to the same value +/-10% of the circle of confusion for depth of field, they both are using the same “interpretation” of acceptably sharp, and as others have pointed out, the human eye has not changed. What has changed is the propensity to blow things up bigger, whether in print, or on our computer monitors,