Four shot stack of a good looking and colorful caterpillar

[DanK]

I don't see any difference. Open a picture by clicking on it and go through the images with the cursor, they're all the same.
I think you've just discovered the benefits of the remote control.

George

I agree. I don't see any difference in focal point among these images. In fact, I didn't realize that I was successfully paging through them in the litebox until I notice the counter at the bottom left of the screen. A few had slightly (very slightly) different exposure, but the focus seemed identical to me.

[Stagecoach]

You are correct Brian in that there are clear differences in each of the four images, consisting of brightness changes that may be due to the clouds/sun or exposure chosen and movement that can be due to wind, camera shutter and a live critter

As for the blue area it's very easy to disguise in this image. I'm sure your software can do this;

Simply de-saturate the Blue channel and that area will change to whiteish. Then make a mask and apply this change by brush to just the offending area. Note : The caterpillars body has a slight blue tint and it's up to you if you address this also.

Here's what you can easily get.



Grahame

[Cogito]

You are correct Brian in that there are clear differences in each of the four images, consisting of brightness changes that may be due to the clouds/sun or exposure chosen and movement that can be due to wind, camera shutter and a live critter
As for the blue area it's very easy to disguise in this image. I'm sure your software can do this;
Grahame

Sorry, Grahame, but the only difference I can see between your and Brian's original image is that yours has a blue glow around the caterpillar's bum. Whether my monitor is calibrated or not (it is, by the way) is immaterial.
I also agreed with the previous 2 posts by George and Dan - can't see the point of a 4-stack.....

[JBW]

George you need either glasses or a new monitor. Each and every one of these shots has a different exposure/brightness and differing in-focus areas.

This is not an I say you say because the differences are shown very plainly by the numbers in Capture 1 Sony Pro. If you can see no difference in the bg of the last two shots at the posted size let alone in the lite box in both brightness and detail either ypour eyes or your equipment needs looking to.

And yes I'm also discovering the benefits of remote control.

[JBW]

Sorry, Grahame, but the only difference I can see between your and Brian's original image is that yours has a blue glow around the caterpillar's bum. Whether my monitor is calibrated or not (it is, by the way) is immaterial.
I also agreed with the previous 2 posts by George and Dan - can't see the point of a 4-stack.....

This is interesting. I see Grahame's efforts as eliminating the blue area. You see a bluish tint and no difference in any of the shots. My eyes and my software tell me the same thing. The shots are all different. My eyes may be acting up but Capture 1 Sony Pro is excellent software.

Perhaps if you dl the shots and put them into your favorite software you will see the difference in the numbers that I see in mine?

[JBW]

I agree. I don't see any difference in focal point among these images. In fact, I didn't realize that I was successfully paging through them in the litebox until I notice the counter at the bottom left of the screen. A few had slightly (very slightly) different exposure, but the focus seemed identical to me.

All I can say Dan is that if you look at the bg you should find many differences in both exposure and sharpness.

[DanK]

All I can say Dan is that if you look at the bg you should find many differences in both exposure and sharpness.

Exposure, yes. Focal point, no. Here is a crop from #2. It's posterized because it is a small jpeg, but it will still make the point.



Now, #9:



The exposure is different, but the focal point appears the same to me.

To show what you should be looking for for focus stacking, take this stacked image:



Here is the image from the stack that has the front area in focus:



And here is the one that has the rear leaves (clear on the left) in focus:



The difference between these last two pictures isn't subtle. The only reason to stack is if you can see areas that are in focus in one shot and out of focus in another.

[JBW]

Exposure, yes. Focal point, no. Here is a crop from #2. It's posterized because it is a small jpeg, but it will still make the point.



Now, #9:



The exposure is different, but the focal point appears the same to me.

To show what you should be looking for for focus stacking, take this stacked image:



Here is the image from the stack that has the front area in focus:



And here is the one that has the rear leaves (clear on the left) in focus:



The difference between these last two pictures isn't subtle. The only reason to stack is if you can see areas that are in focus in one shot and out of focus in another.

There is a brown leaf that hangs straight down. The leaf plainly has different areas in focus in the two shots you posted.

I'm not sure about your belief that the only reason to stack is if you can see a major difference between the areas in focus.

Stacking removes noise, can bring out subtle colors and help to create a 3D effect. At least it does with the software I use.

[Stagecoach]

Sorry, Grahame, but the only difference I can see between your and Brian's original image is that yours has a blue glow around the caterpillar's bum.

Really

That's interesting because the procedure I used did not, and could not, affect anything on the caterpillars body rear end. Have another look at the crops that show the 'blue' area.

No 1 - Brian's original posted image in post 1


No 2 - My modified image in post 22


It would be helpful if you can explain exactly where this blue glow is that has been added, because neither my eye-site or RGB values can recognise it.

Hopefully you will reply to this question.

Whether my monitor is calibrated or not (it is, by the way) is immaterial.

Absolutely, difference is difference.

I also agreed with the previous 2 posts by George and Dan - can't see the point of a 4-stack.....

For info my comments have no reference to whether there is a 'point' to stacking these four images, my comments are simply based on facts specific to the content of each image.

[Stagecoach]

Exposure, yes. Focal point, no.

Dan,

I suspect what Brian may be referring to is the 'apparent' sharpness of an edge due to its lighting which affects its contrast between near and far subject. This is assuming his camera is in manual focus, not auto, where the focus plane distance has to remain fixed.

In a discussion the other day I posted a couple of pics of Sansiveria plant leaves with and without a polariser and the change in lighting produced a very noticeable 'apparent' edge sharpness in certain areas.

[JBW]

Dan,

I suspect what Brian may be referring to is the 'apparent' sharpness of an edge due to its lighting which affects its contrast between near and far subject. This is assuming his camera is in manual focus, not auto, where the focus plane distance has to remain fixed.

In a discussion the other day I posted a couple of pics of Sansiveria plant leaves with and without a polariser and the change in lighting produced a very noticeable 'apparent' edge sharpness in certain areas.

I could be referring to that. It was in manual focus. And there are edges not only at the edge of the leaves et alli but also within them.

[Cogito]

Really
It would be helpful if you can explain exactly where this blue glow is that has been added, because neither my eye-site or RGB values can recognise it.

Hopefully you will reply to this question.

Mea culpa! It's Brian's with the blue bum.

[DanK]

It was in manual focus.

There's your answer. If you focused manually, the focus point would only change if you changed the focus manually or moved the camera. Lighting has nothing to do with it. It may be able to affect the appearance of sharpness--where details is most apparent--but it can't change the point of focus.

[JohnRostron]

I cannot see any difference between these four images. As far as I can see, this is certainly a stacked image, but not a focus-stacked image. There are many useful things you can do with a stack, such as (as Brian says) eliminating noise. You can also eliminate stray objects in one of the images (a passing bug, say). Or evening out lighting, as in Brian's Stone Sculpture posting. I find the stacking facility in Affinity is much easier to utilize than that of Photoshop. I have not tried stacking in Capture One, but would be interested to know what algorithm you used in C1 Brian.

John

[DanK]

Indeed. I should have written "the only reason to FOCUS-stack is... I was responding to what Brian wrote, which suggested that focus stacking is the issue he is working on:

For now i am letting the natural light create different focal area as it creates different brightness areas.

Shortly I'll be working on the classical change the focus DoF to bring more of the shot into focus.

My main point was simply that lighting doesn't affect the point of focus. The point of focus is purely a matter of distance and the characteristics of the lens. It's possible that some area in one of the images looks a little sharper than the same area in another; perhaps the camera moved slightly, or the leaf did. But that isn't a change in the point of focus.

[JBW]

I cannot see any difference between these four images. As far as I can see, this is certainly a stacked image, but not a focus-stacked image. There are many useful things you can do with a stack, such as (as Brian says) eliminating noise. You can also eliminate stray objects in one of the images (a passing bug, say). Or evening out lighting, as in Brian's Stone Sculpture posting. I find the stacking facility in Affinity is much easier to utilize than that of Photoshop. I have not tried stacking in Capture One, but would be interested to know what algorithm you used in C1 Brian.

John

Actually John I stack in Fiji and I haveno idea of the engine they use

[JBW]

Indeed. I should have written "the only reason to FOCUS-stack is... I was responding to what Brian wrote, which suggested that focus stacking is the issue he is working on:



My main point was simply that lighting doesn't affect the point of focus. The point of focus is purely a matter of distance and the characteristics of the lens. It's possible that some area in one of the images looks a little sharper than the same area in another; perhaps the camera moved slightly, or the leaf did. But that isn't a change in the point of focus.

Not to argue because as everyone knows I'm not a techy but why is it that the focus often gets stolen by the brightest area?

[DanK]

Not to argue because as everyone knows I'm not a techy but why is it that the focus often gets stolen by the brightest area?

I'm not sure what you are referring to. I don't have the experience of the focus going anywhere as a result of lighting. Are you talking about using AF with multiple AF points? The only way I can think of this happening is if you use AF with multiple points. The camera then has to select among them. It's possible that the camera detects less contrast in dim areas and therefore selects a point in a brighter area. If that is what is going on, it is not brightness affecting the plane of focus. It's brightness affecting the cameras choice of an AF point to use. In this case, this wasn't possible because you said you used manual focus. In that case, brightness has nothing to do with where the focal plane is. It is wherever you set it, and it stays there until you change it or move the camera. So if you want to use focus stacking to increase DOF in macro work, you will have to change the plane of focus (or have a computer do it for you). Waiting for changes in lighting won't do it.

[Stagecoach]

why is it that the focus often gets stolen by the brightest area?

I'm lost here Brian and agree with what Dan has said.

With your question you need to clearly clarify if you are referring to using the camera in manual or AF focusing mode.

I also suspect there is some ambiguity to the terms you are using, it is not clear if your reference to 'focus' means the focal plane (e.g. the subject to sensor distance changing) or the 'apparent' sharpness of an area?

[Stagecoach]

Mea culpa! It's Brian's with the blue bum.

Perhaps more time reading posts with an aim to constructive participation and less haste in trying to be clever would save such mistakes.