relmet454 Loc: Central Minnesota

I am thinking of experimenting with HDR in portraits, any thoughts? How about combining HDR with focus stacking? ( mainly for shots to get a great dof) I think I will try an HDR set of 3 focused on a front object and then nt moving anything same HDR focused on far object and then try to combine?

rook2c4 Loc: Philadelphia, PA USA

I just can't imagine combining multiple images for both focus stacking and HDR to work very well if done combined in one step. There would be too much trying to pull detail out of blurred (out-of-focus) areas, which I don't think would yield very desirable results, possibly making the final image look excessively grainy and "dirty". But nothing wrong with experimenting.

relmet454 Loc: Central Minnesota

Now that I think about it I think you are right, it would be tricky.

I think if I took 3 pairs of photos it might work its all in the processing. shoot the 3 pairs while adjusting the focus and the exposure bracketing for each pair. Then take and do the focus stacking on each pair, creating 3 single photos each at a different exposure and then use those for the HDR? Its a odd idea but worth a try to see if I could get it to work.

rook2c4 Loc: Philadelphia, PA USA

Sure, give it a try! But seems like a lot of work. I'm not sure why you would want to do focus stacking with a portrait photo when you could simply adjust aperture to get the desired DOF. Unless of course you are doing portraits of insects, etc.

Chinaman Loc: Adelaide, South Australia, Australia

You'll need a head restrainer like they use to have in the old days of portrait photography for the person to keep absolutely still! I believe focus stacking is most useful in macro work where you can't increase the depth of field by usual means - f/stops, camera-to-subject distance, etc.

Jambulee Loc: San Antonio del Mar,Tijuana,Mex

here is a link to one I did a couple years ago: http://lightraysphotography.smugmug.com/organize/Flowers/Focus-Stacked/i-WzXtgxX its not a portrait tho but a still life in my window

fjrwillie Loc: MA

I can't see your link it is asking for a login

Jambulee Loc: San Antonio del Mar,Tijuana,Mex

Ok try this one http://lightraysphotography.smugmug.com/Flowers/Focus-Stacked/i-WzXtgxX/1/L/Sunstatia_Mango_HDR_1-L.jpg

fjrwillie Loc: MA

that worked

conkerwood

I have done quite a lot of work with this idea. There are a couple of pitfalls which make it difficult to work in the situation you describe, but I will get to those. Firstly the best method is to take your series of 3 bracketed pics (-2 0 +2) at various focus points as you suggest. (I have used up to 30 receding focus points trying for a really big DOF with a very close subject) Then combine all of the -2 using something like Helicon Focus then all of the 0 shots and all of the +2 shots. The three shots you end up with are then taken into photomatix or whatever HDR software you use to produce the HDR. The HDR result will be as you expect and if you are doing macro work then as long as you are careful you can end up with a fantastic result. BUT and this is the killer that I never got around, if your pic includes a foreground object which is close and a background which is far, both of which are focussed on in different brackets of shots, you will run into the problem of blooming. By this I mean that if you focus on a far point then a much closer object will be obviously be out of focus. Being out of focus means that it blurs with the blurred area being larger than the object would be if it was in focus. The more out of focus the wider the blur. So when you come to merge your stack you will end up with an in focus foreground subject, an in focus background but there will be a blurred area around the subject because the out of focus blur is larger than the in focus foreground object which you are trying to cover it with. That blur around the object is what is called blooming. The HDR is not an issue, it can be done, but the blooming that arises in focus stacking is the problem in all but a few very specific instances such as macro.

There is one other major issue and thats light. Since the process you are describing can take some time to get the focus adjusted and the brackets taken, anything taken outside risks the light changing which can really mess up the stacking process. Also the amount of time involved increases the chance of movement. I did spend quite a few months working on it and got some passable results but in the end I decided it wasn't worth the effort. But maybe you might come to a different conclusion.

Hope this makes sense.

Peter

Chinaman Loc: Adelaide, South Australia, Australia

Peter, with the 'blooming' problem, has this to do with a wider aperture that was used? You didn't mention what you used. It seems ironic that it doesn't happen in macro shots, where logically, it would be the type of shots that would show this problem up.
I have seen landscape images that were done with 3 images at f-8, focused on the front, midpoint and distant and aligned in Photoshop, and there was no blooming. Maybe there needs to be some layer masking and brushing to eliminate them.

conkerwood

A simple experiment. Set up a tripod set up an object a couple of metres away in front of a long open park. Adjust the focus so that the object in front is in focus and take a shot. Then without moving the camera or changing the settings refocus on a distant point and take the shot. Take both pics into PS and layer one on top of the other, set the transparency at 50% so you can see through. If you zoom in you can see that in the long focus shot the blur around the OOF object makes it larger than the object in the close focus shot.
If you use a mask and paint in all the in-focus areas from both pics you will end up with a blur where the close area covers the distant area because that area is not in focus in either shot. If you go to this post

http://www.uglyhedgehog.com/t-100673-1.html#1709884
and look at the petals at the top you can see the blurred area on the leaves behind even though all the rest of the leaves are in focus. Cloning is a solution but that less than ideal. It is possible to do it with landscapes as long as there are no close objects over distant background. It works ok with insects and bugs because they can be positioned so there is a continual surface from front to back but if you get the wrong angle and have say an antennae at the front sticking up over the back of the insect you will end up with blooming around the antennae.
Hope this makes sense

Peter

Chinaman Loc: Adelaide, South Australia, Australia

OK, so I am discussing this issue with no actual focus stacking experience yet, only with theory, logic and other photographic experience.
My understanding of blooming is a bit like merging 2 layers - one with a sharply focus image, say a flower, and the other a blurred version of the same image. The blurring causes a diffusion of the outlines of the flower, making the flower larger in size to the sharp flower. So merging the 2 together will show the sharp flower with a blurred outer rim.
So it follows that if a wide aperture is used, there will be more areas of out-of-focusness infront of and behind the point of focus compared to if a smaller aperture is used. So as the focus is shifted from front to back, most of the front areas will be out of focus. When they are all merged, those out-of-focus areas may not be completely covered and show through in certain parts.
What I am trying to ask is this: is blooming likely to occur if a small aperture is used. With macro work, the dof is so narrow that using a wide aperture is only going to compound the issue. Normally, using a small aperture in a landscape shot can get everything sharp from front to back. So using 3 shots focusing on the front, middle and back should ensure that it will definitely be sharp from front to back. Hence I think blooming should not be an issue with landscape and non-macro work, but should be a problem with macro work. But earlier on, you said that it is not an issue with macro work -
"but the blooming that arises in focus stacking is the problem in all but a few very specific instances such as macro."
That, does not sound logical to me. But, there is atomic physics and then there is quantum physics!

Jambulee Loc: San Antonio del Mar,Tijuana,Mex

Peter you can get rid of the blooming problem using Zerene Stacker this program allows you to choose which image in the stack you wish to use for that particular object and paint it into the final image. You can paint in or out what ever you want in focus or out of focus. When you have some blooming around a focused part then find the same part where there is no blooming in another frame and paint around the focused area and the blooming will disappear.

conkerwood

Yes I have used Zerene stacker and helicon focus and CS6 so I know what you are saying. But I am saying that in the circumstance when you have a near object in front of a far object then you will have no frames where there is no blooming. If the far object is in perfect focus there must be some blurring from the near object so you have nothing to paint it out with. Of course you can take a number of stacked shots and make a compromise of having a nearly in focus far object behind an in focus near object in which case the blooming is less obvious or even undetectable, but that of course defeats the purpose, which was to have everything in focus from front to back. I would love to be wrong believe me and if someone can do it then I am ready to learn. So can someone set up an object say 30 cm tall, at a distance of say 2.5 meters in front of a long receding scene 500 meters or more so that the front object covers at least part of the most distant area of the scene and takes up say half the frame, use whatever aperture you like and as many, pics in the stack as you like and whatever software you like. If you can produce a pic where the full scene is in focus from front to back with no blooming and no cloning repairs then I will take my hat off to you and I will be picking your brains as to how you did it.

Its a fascinating topic.

Peter