Yet another X-T4 Spec thread; 6.5 stops IBIS...

Stabilize yourselves, this is for the IBIS chasers out there:

From Fujirumors comes the latest rumor: up to 6.5 stops IBIS with certain prime lenses. This is one stop better than the published 5.5 stops of the X-H1 paired with the 35mm f1.4. It will be interesting to find out if Fuji will develop synchronized IS between camera and OIS lenses for even better performance.

I guess I'll sell all my stock in Manfrotto and Gitzo.

Sorry but I don't have a "roll eyes" emoji.

Pretty exciting..as is what I assume will be the further drop in XH1 prices, both new and used.

We are approaching true Last Camera territory here. This thing plus a 16-55 will be tremendously capable.

Lettermanian said:

It will be interesting to find out if Fuji will develop synchronized IS between camera and OIS lenses for even better performance.

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They did that with the X-H1, no reason they won't do that for the X-T4, just firmware/software implementation on the communication between lens and body.

Discussed here:
https://www.dpreview.com/forums/thread/4458132

Lettermanian said:

up to 6.5 stops IBIS with certain prime lenses. This is one stop better than the published 5.5 stops of the X-H1 paired with the 35mm f1.4.

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This is - at this time - pure marketing. I have the X-H1, the 35/1,4 was the first lens I tried on it. I had and have reliably sharp images down to 1/5s, from 1/4s it became unreliable. Some sharp, lots of unsharp at 1/4s.

Even if we take 1/50s (FF equivalent) as "normal" lower shutter speed, 1/3s would just be 3 stops. 6 stops would mean around 1s. Quite a bit away from what I get with the X-H1.

Bernie Ess said:

Lettermanian said:

up to 6.5 stops IBIS with certain prime lenses. This is one stop better than the published 5.5 stops of the X-H1 paired with the 35mm f1.4.

Click to expand...

This is - at this time - pure marketing. I have the X-H1, the 35/1,4 was the first lens I tried on it. I had and have reliably sharp images down to 1/5s, from 1/4s it became unreliable. Some sharp, lots of unsharp at 1/4s.

Even if we take 1/50s (FF equivalent) as "normal" lower shutter speed, 1/3s would just be 3 stops. 6 stops would mean around 1s. Quite a bit away from what I get with the X-H1.

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Everybody is different. Some shake more than others, some have better technique, etc.

Same reason some do 3X4, better than than published shots per charge and others get less. All you can do is measure to a standard so each camera can be compared against the other.

6.5 stops is unreal. Olympus says 8 to 8.5 stops with a few qualifiers. Reason enough to upgrade. Between 6.5 and ISO invariance, darkness is becoming a mote point. (That's without AI stacking.). Let's roll the clock forward a few years and what we see now will become silly. Roll on, Fuji. Roll on.

Lettermanian said:

...It will be interesting to find out if Fuji will develop synchronized IS between camera and OIS lenses for even better performance.

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I thought they already had this in the XH1.

DarnGoodPhotos said:

Lettermanian said:

...It will be interesting to find out if Fuji will develop synchronized IS between camera and OIS lenses for even better performance.

Click to expand...

I thought they already had this in the XH1.

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They do.

HatWearingFool said:

All you can do is measure to a standard so each camera can be compared against the other.

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Yeah, but the standard better be representative for a broad user base.

Not for a few indviduals who have incredibly calm muscles. My values - also without IBIS - are typically a bit better than average (certainly not exceptional), so my numbers with IBIS are probably not too far off.

Bernie Ess said:

HatWearingFool said:

All you can do is measure to a standard so each camera can be compared against the other.

Click to expand...

Yeah, but the standard better be representative for a broad user base.

Not for a few indviduals who have incredibly calm muscles. My values - also without IBIS - are typically a bit better than average (certainly not exceptional), so my numbers with IBIS are probably not too far off.

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. . . but there are standards! Some os are worse than the standards, some are better. The standards are based on focal length and degree of stabilization. However, understanding these standards is next to impossible. This web page would be a good start: https://www.lensrentals.com/blog/2019/01/how-image-stabilization-works-in-camera-and-in-lens/

Bernie Ess said:

HatWearingFool said:

All you can do is measure to a standard so each camera can be compared against the other.

Click to expand...

Yeah, but the standard better be representative for a broad user base.

Click to expand...

Not really. The way they arrive at shots per charge is pretty ridiculous in my opinion. But the important thing is consistency.

If shots per charge doubles that tells me if I upgrade I’ll get double my usual. If you know you get 2 less stops of stabilization than advertised at least you have a base point of reference. Now you’ll probably get 4 instead of 3 stops on the new camera.

olympus claims ~8 stops now, so regardless of what you get it’s probably going to be a stop or two worse on the x-t4 than you’d get on the em-1.3.

Bernie Ess said:

Not for a few indviduals who have incredibly calm muscles. My values - also without IBIS - are typically a bit better than average (certainly not exceptional), so my numbers with IBIS are probably not too far off.

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Dpreview’s review figured the average person could expect 3.3 stops. Of course that was before the improved firmware.

Bernie Ess said:

HatWearingFool said:

All you can do is measure to a standard so each camera can be compared against the other.

Click to expand...

Yeah, but the standard better be representative for a broad user base.

Not for a few indviduals who have incredibly calm muscles. My values - also without IBIS - are typically a bit better than average (certainly not exceptional), so my numbers with IBIS are probably not too far off.

Click to expand...

It is not. It is based on a standard defined in a document with a standardized testing procedure with a "certified" test jig.


If you don't want to pay for a copy of the standards


Two things stand out. Roll, pitch and yaw motions are pretty easy to compensate since they are angular and the sensor only has to be moved angularly and not far. The other two dimensions x and y requires a shift of the sensor which requires a larger shutter and can be impacted by the lens image circle. It is x and y where the limitations will show up.

If I can shoot my 35 hand held at 1/15 (and I actually can on my Pro2/3) then 6 stops means I can hand hold the camera for 2 seconds and get a razor sharp image. Highly unlikely. Secondly depending on the lens there will be significant issues in x and y. With roll, pitch and yaw, the angular correction is magnified with focal length - which is the reason OIS works better than IBIS for long lenses.

For x and y, the error is magnified by a long lens but the corrections are not. With a long lens it is easier to hit the stops - the maximum deviation from center in the linear x and y directions. When that happens the IBIS will do no more.

Camera companies have to have a standard and they have to have a way of testing it. I expect most of the test limit the excursion in the linear directions. But that is exactly where the image stabilization will fail since the sensor can't move past the shutter opening and it can't move past the physical stops on the camera and the actuators have a finite limit for their movement.

But it sure sounds good, but I remember people talking about the image "jumping" in the H1 - primarily in video.

Bernie Ess said:

Lettermanian said:

up to 6.5 stops IBIS with certain prime lenses. This is one stop better than the published 5.5 stops of the X-H1 paired with the 35mm f1.4.

Click to expand...

This is - at this time - pure marketing. I have the X-H1, the 35/1,4 was the first lens I tried on it. I had and have reliably sharp images down to 1/5s, from 1/4s it became unreliable. Some sharp, lots of unsharp at 1/4s.

Even if we take 1/50s (FF equivalent) as "normal" lower shutter speed, 1/3s would just be 3 stops. 6 stops would mean around 1s. Quite a bit away from what I get with the X-H1.

Click to expand...

f you have good technique, it's like having a couple of stops of ibis. However, it doesn't combine well with ibis.

In fact, when I had a Sony a7rii (which had a pretty poor ibis implementation, but for some reason got a CIPA 4.5 stop rating) I barely noticed if it was off or on. I probably got 1 stop or so. Shakier people that needed 1/125 to keep a 35mm lens steady found they got a decent 3 stops of ibis.

Truman Prevatt said:

Bernie Ess said:

HatWearingFool said:

All you can do is measure to a standard so each camera can be compared against the other.

Click to expand...

Yeah, but the standard better be representative for a broad user base.

Not for a few indviduals who have incredibly calm muscles. My values - also without IBIS - are typically a bit better than average (certainly not exceptional), so my numbers with IBIS are probably not too far off.

Click to expand...

It is not. It is based on a standard defined in a document with a standardized testing procedure with a "certified" test jig.

http://www.cipa.jp/image-stabilization/index_e.html

If you don't want to pay for a copy of the standards

https://www.image-engineering.de/co...rds and the challenges for mobile imaging.pdf

Two things stand out. Roll, pitch and yaw motions are pretty easy to compensate since they are angular and the sensor only has to be moved angularly and not far. The other two dimensions x and y requires a shift of the sensor which requires a larger shutter and can be impacted by the lens image circle. It is x and y where the limitations will show up.

If I can shoot my 35 hand held at 1/15 (and I actually can on my Pro2/3) then 6 stops means I can hand hold the camera for 2 seconds and get a razor sharp image. Highly unlikely. Secondly depending on the lens there will be significant issues in x and y. With roll, pitch and yaw, the angular correction is magnified with focal length - which is the reason OIS works better than IBIS for long lenses.

For x and y, the error is magnified by a long lens but the corrections are not. With a long lens it is easier to hit the stops - the maximum deviation from center in the linear x and y directions. When that happens the IBIS will do no more.

Camera companies have to have a standard and they have to have a way of testing it. I expect most of the test limit the excursion in the linear directions. But that is exactly where the image stabilization will fail since the sensor can't move past the shutter opening and it can't move past the physical stops on the camera and the actuators have a finite limit for their movement.

Click to expand...

I am not wild about CIPA, however . . . and maybe why Fuji incorporates OS and IBIS combined in it's longer lenses? Anyway, a lot of this is hype, and does not apply to all lenses. Nice explanation on your part. Thanks.

Truman Prevatt said:

But it sure sounds good, but I remember people talking about the image "jumping" in the H1 - primarily in video.

Click to expand...

Yep! Sure sells cameras, also.

Truman Prevatt said:

Bernie Ess said:

HatWearingFool said:

All you can do is measure to a standard so each camera can be compared against the other.

Click to expand...

Yeah, but the standard better be representative for a broad user base.

Not for a few indviduals who have incredibly calm muscles. My values - also without IBIS - are typically a bit better than average (certainly not exceptional), so my numbers with IBIS are probably not too far off.

Click to expand...

It is not. It is based on a standard defined in a document with a standardized testing procedure with a "certified" test jig.

http://www.cipa.jp/image-stabilization/index_e.html

If you don't want to pay for a copy of the standards

https://www.image-engineering.de/co...rds and the challenges for mobile imaging.pdf

Two things stand out. Roll, pitch and yaw motions are pretty easy to compensate since they are angular and the sensor only has to be moved angularly and not far. The other two dimensions x and y requires a shift of the sensor which requires a larger shutter and can be impacted by the lens image circle. It is x and y where the limitations will show up.

If I can shoot my 35 hand held at 1/15 (and I actually can on my Pro2/3) then 6 stops means I can hand hold the camera for 2 seconds and get a razor sharp image. Highly unlikely. Secondly depending on the lens there will be significant issues in x and y. With roll, pitch and yaw, the angular correction is magnified with focal length - which is the reason OIS works better than IBIS for long lenses.

For x and y, the error is magnified by a long lens but the corrections are not. With a long lens it is easier to hit the stops - the maximum deviation from center in the linear x and y directions. When that happens the IBIS will do no more.

Camera companies have to have a standard and they have to have a way of testing it. I expect most of the test limit the excursion in the linear directions. But that is exactly where the image stabilization will fail since the sensor can't move past the shutter opening and it can't move past the physical stops on the camera and the actuators have a finite limit for their movement.

But it sure sounds good, but I remember people talking about the image "jumping" in the H1 - primarily in video.

Click to expand...

You got it backwards. It's the angular shake that is the hardest to compensate.

First, sensors don't move angularly. They move in the x, y focal plane and rotate about z.

To compensate for a tilt , the sensor has to shift by tan(alpha)*F (for small alphas), where alpha is the tilt and F is the focal length. So for alpha = 1deg and F=200 mm, the sensor has to shift by 3.5 mm.

On the other hand, if you move the camera parallel to the focal plane by X, then the image shifts by X*F/L, where L is the distance to the object. So, unless you take macros or close ups, the shift is small. For example, if you shift your camera by 2mm, and your lens is F=200mm, and the object is at, say, 5 m, then the sensor has to be shifted by 0.08mm

I'd be very careful before celebrating this claim gents. 6.5 stops out of a three axis IBIS means that there's something else at play besides the Ibis system itself, and you may not love it.

Fuji Maine said:

I'd be very careful before celebrating this claim gents. 6.5 stops out of a three axis IBIS means that there's something else at play besides the Ibis system itself, and you may not love it.

Click to expand...

Why would it only be 3 axis? It was 5 in the x-h1.

Adamant said:

We are approaching true Last Camera territory here...

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Shhh. My wife might hear you.