How to: FOCUS STACKING

Please post your workflow and tips on how to get best results with FOCUS STACKING

Thanks!!

1. set up on a tripod, IS off.
2. decide what aperture is required - you need enough DOF so that everything in a small portion of the image is in focus. If you have something in the foreground you need enough DOF to have the background directly behind it in focus.

If I am doing landscapes, I will then start at the minimum focus distance and take shots with a 2s timer delay or remote shutter as I manually move the focus until I get to infinity. From experience I know how many shots I will need and approximately at what interval. Usually the amount you will turn the focus ring will be about the same between each shot. I will use this for up to 6-5 shots if going from very near to infinity.

If something is moving in the frame (e.g. a car or person you don't want to include) then I will take duplicate shots at the same focus distance of the moving sumbject if using the manual option.

If macro, then I will likely be taking many more shots, maybe up to 30, with small increments, so I use Magic Lantern focus stacking to move the focus from near to far. This needs a setup that is a whole manual in itself. Otherwise you will need to tether to a computer to control the focus.


Do basic raw conversion to 16bit .tiff in preferred raw converter. I leave it pretty low contrast, unsaturated, no clarity or anything like that. I just want NR, CA correction and highlight reduction/shadow recovery at this stage. I try not to do any distortion corrections either, it is better to do that afterwards if your software allows - distortion can vary with focus distance a bit.

Put .tiff images into Helicon Focus (it was the only 'real' option when I started, and still works fine) and use the default 90% of the time.

Then go around the image cleaning up any issues by paining in parts of a particular image to the main image - this is needed depending on the complexity of the scene. Sometimes it is not needed at all. If things moved a bit during the shooting, you will need to choose one of the duplicates you shot or just the best option if you didn't shoot duplicates or were doing it automated.

Finally finish the image in PS.

There are many more uses than just this simple workflow, sometimes just foreground/background with landscapes where something is moving. Also I sometimes focus stack at f8-f11 and then add a shot at f2.8-f4 for the background and use Helicon Focus to blend all of them.

There are lots of ways to do focus stacking. I have found that you don't have to be particularly fastidious about how you do it and still get good results.

Some people use automated rails, some use tripods or camera stands, some vary the focus, and others vary the distance. They can all be successful, but you can also be very casual about it and get very good results.

Focus stacking sounds highfalutin, but it is easy. I suggest you try an example to prove this to yourself. Select an interesting subject for focus stacking - like a flower or a toy car. Mount a suitable lens so the subject looks nice and you can focus the subject. Set your camera up on a tripod or camera stand. In manual focus, peering through the viewfinder, vary the focus from the front to the back of the subject, and note the positions of the focus ring. Mark the near and far positions on the focus ring using bits of tape or whatever.

Now shoot about 10 shots varying the focus stepwise, going from near to far (or reverse). Divide the focus steps evenly. It is OK to guess. It is not necessary for the steps to be equal, but it is good if the intervals are similar. The aperture can be around f/8 or 5.6 or 4. Don't try to stop down for DOF. You will get your DOF from the stacking. Shoot JPGs. Raw is also OK, just convert to JPG afterwards.

Now download Zerene Stacker, trial version, and install. Launch the program, click on Stack, drag the JPGs into the window on the left, and let the program combine the photos. Then save the stacked photo! Come back here and post the result.

If you are doing extreme closeup work, then you will want to be more fussy about how you make the stack of JPGs, but you can deal with that later.

ejenner wrote in post #18348776
1. set up on a tripod, IS off.
2. decide what aperture is required - you need enough DOF so that everything in a small portion of the image is in focus. If you have something in the foreground you need enough DOF to have the background directly behind it in focus.

If I am doing landscapes, I will then start at the minimum focus distance and take shots with a 2s timer delay or remote shutter as I manually move the focus until I get to infinity. From experience I know how many shots I will need and approximately at what interval. Usually the amount you will turn the focus ring will be about the same between each shot. I will use this for up to 6-5 shots if going from very near to infinity.

If something is moving in the frame (e.g. a car or person you don't want to include) then I will take duplicate shots at the same focus distance of the moving sumbject if using the manual option.

If macro, then I will likely be taking many more shots, maybe up to 30, with small increments, so I use Magic Lantern focus stacking to move the focus from near to far. This needs a setup that is a whole manual in itself. Otherwise you will need to tether to a computer to control the focus.


Do basic raw conversion to 16bit .tiff in preferred raw converter. I leave it pretty low contrast, unsaturated, no clarity or anything like that. I just want NR, CA correction and highlight reduction/shadow recovery at this stage. I try not to do any distortion corrections either, it is better to do that afterwards if your software allows - distortion can vary with focus distance a bit.

Put .tiff images into Helicon Focus (it was the only 'real' option when I started, and still works fine) and use the default 90% of the time.

Then go around the image cleaning up any issues by paining in parts of a particular image to the main image - this is needed depending on the complexity of the scene. Sometimes it is not needed at all. If things moved a bit during the shooting, you will need to choose one of the duplicates you shot or just the best option if you didn't shoot duplicates or were doing it automated.

Finally finish the image in PS.

There are many more uses than just this simple workflow, sometimes just foreground/background with landscapes where something is moving. Also I sometimes focus stack at f8-f11 and then add a shot at f2.8-f4 for the background and use Helicon Focus to blend all of them.

thanks for this: I did try helicon focus but wasn't sure what to do about all the movement in the tree tops (landscapes)

It is only landscapes where I'd be using it.

I found it really hard to work with it seemed that the increments I did would cover all focus in the image I tried but there were still big areas not in focus. I must have been doing something wrong....

Archibald wrote in post #18348792
There are lots of ways to do focus stacking. I have found that you don't have to be particularly fastidious about how you do it and still get good results.

Some people use automated rails, some use tripods or camera stands, some vary the focus, and others vary the distance. They can all be successful, but you can also be very casual about it and get very good results.

Focus stacking sounds highfalutin, but it is easy. I suggest you try an example to prove this to yourself. Select an interesting subject for focus stacking - like a flower or a toy car. Mount a suitable lens so the subject looks nice and you can focus the subject. Set your camera up on a tripod or camera stand. In manual focus, peering through the viewfinder, vary the focus from the front to the back of the subject, and note the positions of the focus ring. Mark the near and far positions on the focus ring using bits of tape or whatever.

Now shoot about 10 shots varying the focus stepwise, going from near to far (or reverse). Divide the focus steps evenly. It is OK to guess. It is not necessary for the steps to be equal, but it is good if the intervals are similar. The aperture can be around f/8 or 5.6 or 4. Don't try to stop down for DOF. You will get your DOF from the stacking. Shoot JPGs. Raw is also OK, just convert to JPG afterwards.

Now download Zerene Stacker, trial version, and install. Launch the program, click on Stack, drag the JPGs into the window on the left, and let the program combine the photos. Then save the stacked photo! Come back here and post the result.

If you are doing extreme closeup work, then you will want to be more fussy about how you make the stack of JPGs, but you can deal with that later.

thanks for this - I'll try the trial version . have you also tried Helicon focus? Just wondered whether one was easier to use than the other...?

I Simonius wrote in post #18348925
thanks for this - I'll try the trial version . have you also tried Helicon focus? Just wondered whether one was easier to use than the other...?

They are both good, but they are different. The stacked products have different appearances. Sometimes Helicon looks better, but when I was trying them, usually Zerene was better. That was a couple of years ago, though. There might have been updates since then.

OK cheers

I Simonius wrote in post #18348924
thanks for this: I did try helicon focus but wasn't sure what to do about all the movement in the tree tops (landscapes)

It is only landscapes where I'd be using it.

I found it really hard to work with it seemed that the increments I did would cover all focus in the image I tried but there were still big areas not in focus. I must have been doing something wrong....

Zerene might be better now.

OK, so focus stacking landscapes is something I do regularly, even more than macro, so I'm going to take the time here to try to provide somethign I hope will be useful and save you some time in the future.

First, it could be that you issue was simply the tree was moving and you need to find a frame with the in-focus tree and paint that in. The stacker will look for edges, and it can think that a leaf is in-focus when it is not if it moves over a part of the background that is smooth. That will create a weird halo-y effect from blending images with the leaves in different positions. A similar thing happens with clouds if they are moving quickly. You often have to paint in the infinity shot for the sky because the stacker picks up the cloud edges on different frames even when you are focused in front of infinity.

However, I also think that a fallacy when doing landscapes is that you don't have to worry about DOF because you cover all focus in the image. For instance, in your case, with the moving (or even a non-moving) tree, you need a shot that gets both the tree and the background directly behind the tree in focus. Otherwise you will not have an in-focus frame to work with because the out of focus tree (when focused on the background) will obscure the part of the image that is in focus behind the tree. This is a limitation of focus stacking that I think many people do not appreciate when they start. If the tree, or object is moving, it is even more important.

It's a little hard to visualize, but when the foreground object is OOF, the edges will blur into the in-focus background. So in effect you never have a shot with the background right next to the tree that is in focus.

So what I would have done is make sure the tree and background directly behind the tree was in-focus in one shot. The stacker might still mess up the tree a bit because it is moving and it looks for edges - so you might have a leaf edge move into a smooth background and the program things it is in focus when it is not really. However, in the case you have enough DOF, then you can paint in the single shot with the tree in focus into the final image.

If you have a landscape with nothing 'sticking up', then you don't have anything in the foreground to obscure the background and you only need to worry about having small enough increments for the aperture you choose.

Take this shot for example:

Personally, if I want to focus stack a landscape shot I just use Ps. "Edit"> "Auto Blend Layers">"Stack images".

OK, this isn't the best example, but I think this experience made me be a bit more careful about DOF when focus stacking. I probably have some old macro examples because there the effect can be more pronounced because of how shallow the DOF can be, even with small apertures.

If you look at the green area, although there is nothing in the background, you can see than the moss in the foreground gets blurred over a wider area when you are focused on the bg. So if you have something with detail in the bg there, you would not be able to see it in the bg focused image. You can kind of see the tree there is obscured. You can also see in the red area how much larger that piece of moss is when OOF.

This is not the clearest example, but I had enough issues with the halo to remember it and realizing the issue. If you can reduce the bluring so that the foreground is just soft when you are focused on the bg, you will usually be just fine.

Thanks for the detailed replies- lots to think about!



I'll get your point about focus stacking at smaller apertures, that makes sense and I think assuming it would work well at wider apertures was probably where I fell down.

I really is just the close foreground and infinity focus conundrum where often with UWA lenses the closest textures/object are very close indeed and short of stopping down to f22 you'll never get the apparent focus to be acceptable, most of the time hyperlocal will do it as long as the nearest textures/object is about 8 feet away (for f8). For the 5DsR this is the optimal f-stop before resolution starts to go into diffraction, though I have to pixel peep to see it, it is there by f11 and by f16 its obvious.

VERY interesting tip about lining up the foreground objects so they don't encroach on the infinite objects- thanks for that!

I Simonius wrote in post #18351393
most of the time hyperlocal will do it as long as the nearest textures/object is about 8 feet away (for f8). For the 5DsR this is the optimal f-stop before resolution starts to go into diffraction, though I have to pixel peep to see it, it is there by f11 and by f16 its obvious.

Right, so it is always a bit of a compromise and yes, I prefer not to use f16 on a 5DIII, so I can see how even f11 you would want to avoid if possible. One thing you can always do is shoot at f8, hyperfocal and then take a shot for the near and a shot for the far/infinity (or even a couple more). If the very near, closer than 8ft is grass or something that doesn't impinge too much on the background, you are set. Even if the nearest object is 8ft away, you can't do worse that your hyperfocal shot and will likely get much/most of the image significantly sharper with the extra shots.

Or, say you need f16 to get the DOF you really want. Take a shot at f16, then set the aperture to f8 and focus stack. You will always have the f16 shot as a backup and can use the other shots, either with or without the f16 shot to fill in what they can - the stacking programs should handle a mix of apertures just fine.

There are lots of 'tricks' you can play like this and most are IMO worth doing. The real trick is knowing what will work and not wasting too much time so you can get on with the next shot. I think that will only come from experience.

I've even tried focus stacking with tilt, but that got too finicky. I will occasionally do a 2-shot focus stack with tilt to get the near corners sharper. And for me just doing that is worth it - like take the usual hyperfocal shot and then just one focused closer, at the near foreground. Since most lenses are weaker in the corners, even at f8, this can sharpen up the image there considerably. I used to do this a lot with my 17-40 in particular.

ejenner wrote in post #18351504
Right, so it is always a bit of a compromise and yes, I prefer not to use f16 on a 5DIII, so I can see how even f11 you would want to avoid if possible. One thing you can always do is shoot at f8, hyperfocal and then take a shot for the near and a shot for the far/infinity (or even a couple more). If the very near, closer than 8ft is grass or something that doesn't impinge too much on the background, you are set. Even if the nearest object is 8ft away, you can't do worse that your hyperfocal shot and will likely get much/most of the image significantly sharper with the extra shots.

Or, say you need f16 to get the DOF you really want. Take a shot at f16, then set the aperture to f8 and focus stack. You will always have the f16 shot as a backup and can use the other shots, either with or without the f16 shot to fill in what they can - the stacking programs should handle a mix of apertures just fine.

There are lots of 'tricks' you can play like this and most are IMO worth doing. The real trick is knowing what will work and not wasting too much time so you can get on with the next shot. I think that will only come from experience.

I've even tried focus stacking with tilt, but that got too finicky. I will occasionally do a 2-shot focus stack with tilt to get the near corners sharper. And for me just doing that is worth it - like take the usual hyperfocal shot and then just one focused closer, at the near foreground. Since most lenses are weaker in the corners, even at f8, this can sharpen up the image there considerably. I used to do this a lot with my 17-40 in particular.

Thanks - yes the 17-40 really needed work to get the corners up to par. Thats why I swapped for the 16-35f4L really

With the 5DsR the tiniest motion throws the advantage over my previous 5D so Im not sure even changing aperture would be possible without some motion creeping in, but the idea is a good one in essence.

I think for simplicity's sake, and specifically with landscapes, takeing one near and one far, or maybe even three shots, near, middle and infinity using hyperlocal on each may be the most workable. [though I think occasionally infinity isn't spot on for even distant trees etc-bit of room for error there too]

I had been trying to focus a shot where the sun had caught a wooden fence just right but there was a near fence, another 14 feet back and a wooden structure sideways on in the middle, and so I took a shot focussed every foot, but it really didn't work at all. It made me realise though that I may have to calibrate my lens too!


I'm not a fan of lots of technical requirements so I may settle on the two or three shot max tactic you describe

thanks again for your detailed explanations

I Simonius wrote in post #18351690
Im not sure even changing aperture would be possible without some motion creeping in,

This is, or should not be an issue. The stackers (Helicon, Zerene) have to re-size and align each shot because changing focus changes the effective FL. So a little movement between shots should be OK. You still want to use a a tripod, but the stackers are usually pretty good since they are set to only moving things a few pixels.

ok thanks