Focus Merging

[FrankMi]

I am hoping that there are techniques available in PS or LR to merge the focus from two objects into one. I know this sounds confusing so I'll demonstrate with the following photos. The shots were taken with the normal lens wide open to minimize the DoF for this experiment.

The area of interest in these photos is the surface of the granite shelf in the foreground. In the first shot, the focus is on the surface and the dust on the shelf can be clearly seen. Please don't tell the wife I shot this before she had a chance to dust!



In the second photo, the focus is on the back wall of the room. Although the dust is no longer in focus, there is now a reflection of the back wall on the surface of the granite shelf.



My goal is to combine the images to get the entire photograph in focus. The trick is in getting BOTH the dust and the reflection in focus on the shelf. So far, the best I've been able to do is this. This is actually the merging of four images to try to get sharp focus from front to back, but the shelf focus experiment only needs two images to demonstrate the principle.



Thank your viewing and whatever suggestions you may have.

[jiro]

I think you did good on that, Frank. You used layering mask, don't you?

[FrankMi]

I think you did good on that, Frank. You used layering mask, don't you?

Hi Willie, thanks for taking the time to look and respond.

Actually I have been trying a number of techniques, starting with PP Edit/Auto-Blend and then touching up with Layers. I tried to use layer masks to blend the two focus images but so far my techniques have been pretty much mutually exclusive. I just don't know the options available anywhere near well enough to even effectively apply what little I have learned but I'm getting there slowly, sometimes painfully slowly. It seems like every time a learn something new I discover how much more I don't know! LOL!

One side benefit of this exercise is I now know I can increase the DoF even with a normal lens in situations where I can get multiple shots at different focus points.

[stevewe88]

Frank, I see you have CS5 at your disposal. Have a look at some tutorials on Focus Stacking on you tube etc, you will be amazed at what it does.

Just take a whole load of images right through the focus range, set CS5 up to stack them and sit back for 5 minutes while it does it's thing.

Much quicker than trying to layer mask it all manually I can assure you

[jiro]

Steve's recommendation is the proper way to do it, Frank. Take heed. Hehehe.

[FrankMi]

Have a look at some tutorials on Focus Stacking on you tube etc, you will be amazed at what it does.

Hi Steve, thank you for the pointers. Now that I know that they call this technique Focus Stacking I was able to watch a number of videos on the process. For the shots above, I was using the Auto-Blend in CS5 as a starting point and had to change the lens focus as I didn't have a slide rail or macro lens. It looks like CombineZM (free) and Helicon Focus are two favorites for Stacking Focus dedicated software. A new world to explore. Thank you!

My real goal is to be able to show the dust (shot # 1) AND the reflection off the wall (shot # 2) on the shelf at the same time. I didn't see anything in the videos that addresses this scenario. It may not be possible but I figured that if it was, someone at CiC would have found a way to do it.

[Ryogenetic]

Frank;
I was looking for other photo stitching threads here on CiC when I came across this thread. It is interesting to see where you got your start with some of the concepts you used in your Project 52. I noticed what you were trying to do and decided to take a shot at it. I only snagged the first two pics; opened both and pasted the second pic to a new layer, added a mask set to screen. Here is the final:



here is what I did:



Ryo
BTW if you have seen any other photo stitching threads...

[FrankMi]

Yep! A great start!

Although I posted the close and far images to show the difference on the granite shelf, there were possible 8-10 images total that were merged using PS CS5 Edit/Auto-Blend Layers to get the final image. My frustration came from the fact that I couldn't find a way to get BOTH the dust and the reflection on the shelf at the same time. I was able to get sort-of a blend of the two but never could get both as sharp as the originals at the same time. In fact the only place where the image is not really sharp is the top of the shelf!

[Snarkbyte]

Hi Frank. You want to try Zerene Stacker . I have been playing aroung with close-ups and image stacking in my Project 52 thread, and I've found ZS to be much better than CS5, particularly in selecting areas of low contrast. For me, it works better than Helicon (which seems to have some issues on Windows 7), and it's even cheaper. See the kumquat images in my Project 52 thread for comparison, and you'll see what I mean. You can download a trial version of ZS at the site referenced earlier in this post. (BTW, I'm not affliated with ZS in any way, and I'm still using the 30-day trial version... just impressed with a good product, and thought I would pass it along. Worth considering, IMO).

[FrankMi]

Thanks for the tip, Al! I'll look into it as focus stacking is one of the toys I'm playing with at the moment.

[Glenn NK]

Focus merging (commonly called focus stacking) is quite common. Most of the people that I know that do it use one of the following programs:

http://hadleyweb.pwp.blueyonder.co.uk/CZM/News.htm

This first one is free and is available online - I've been using it for four or five years.

This next one has a price tag:

http://www.heliconsoft.com/heliconfocus.html

I'm presently evaluating this one using the limited time trial version (the finished image has a watermark on it).

My initial impressions are that Helicon Focus works quite a bit better - few artifacts in the finished image. I know from personal experience that it is much faster. While speed not seem important, even five or six images can take a few minutes with CombineZ, but quite a bit less with Helicon.

On the naturescapes.net site, one of the users posted a stacked image from 23 images. I wouldn't even think of this with CombineZ.

I have no information on Zerene Stacker, but will probably try it in the near future.

Glenn

[GrahamH]

Hi Frank,
Okay, disclaimer - I've never tried focus stacking myself. But hopefully my comments will trigger an idea in someone else.

As far as I know, as the dust AND the reflection are in the the same place, if the in-focus dust is selected then to get the reflection in focus you would need to be able to select the spaces between the dust. This seems a pretty big task for a program to differentiate between the two spaces as the dust is so small. It could easily look like noise.
Which would mean that you could take the reflection in-focus version and ADD noise deliberately to mimic the dust.

Or () you could take the reflection in-focus shot, use a layer mask and manually reveal EACH dust mote. See you in a couple of years when you're done. (Couldn't resist thinking outside the box for fun).
Possibly, if the dust is consistently darker/lighter than the reflection shot, you could get the dust to reveal itself using belnding modes (Darken/Lighten).

Anyone else have an idea?

Graham

[DanK]

If you are going to do a lot of focus stacking, I would second snarkbyte's suggestion of Zerene. It's what I use, and many of the best macro photographers I know use it as one of their primary tools for this. It has a number of advantages over CS5 for this. One is that it has two entirely different stacking methods, DMap and PMax, that are advantageous for different kinds of shots. It also has very powerful retouching tool that allows you to paint from individual frames or from a composite created with the other method. this can be very useful for getting rid of halos and other artifacts that can arise in stacking, e.g., if there is too much distance front-to-back between things that are in focus in different frames.

You wrote:

I didn't have a slide rail or macro lens.

You don't need either one. A macro lens lets you get closer, and because macro entails very narrow DOF, macro photographers more often use stacking, but you don't need a macro lens to stack. Re rails: they are handy for some macro work, particularly at very high magnifications, but at 1:1 - 2:1, I make do fine without one--I just change the focus very slightly between shots.

Here's one stacked with Zerene, with I believe 5 images. I deliberately left out of the stack images that had the petals in the background in focus. The petals on the left were too close to in-focus on the rear-most image that I needed to keep the anthers in focus, so I used the retouch tool to paint that area from the front-most image in the stack.

[Geoff F]

Previously, I have tried some of the software which has been mentioned for focus stacking and found problems.

One was too expensive, one wouldn't work with my computer and the other produced excessively sharpened results which just didn't look natural.

However, like Frank, I have been experimenting with doing this using CS5. And, eventually, things started to make sense.

The potential problems with using the Auto Blend method (after auto aligning the layers) seems to be that it selects then blends the best bits from the layers. So it is either 'on or off' in it's auto masking which can sometimes produce a rather harsh result and I end up going over some areas with a blur brush after combining the layers.

An alternative is to simply align layers and use masks to bring out the best bits which can be gradually merged to give a more natural finish. And this also means that individual layers can selectively receive different amounts of sharpness (Unsharp Mask etc).

Basically with CS5, open the images on separate layers (from a number of options) then Select All Layers. Use Auto Align Layers (from Edit menu). Individually select a layer, add a mask and edit to just reveal the required areas.

I normally find that I start with the foreground image than add a hide all mask to subsequent layers and brush to reveal what is required.

An alternative starting method for CS5 is to use File menu - Scripts - Load Layers and add required files. Select Attempt to Auto align Layers then continue as the previous method.

This I find, works OK with CS5 but when I suggested this method to a friend with Elements 10 he has had problems with doing the auto aligning stage. But there might be alternative methods with PSE 10 of which he currently isn't aware.

I don't know about how this would work with other software though.

And, of course, these methods can be used for a variety of scenes including landscapes, providing there isn't excessive wind or other movements which prevents the auto aligning.

[FrankMi]

Thank you for the feedback, Geoff. I have found much the same thing and I'm hoping that one of the products mentioned will make the process easier to manage.

I've found that doing the Auto-Align and Auto-Blend leaves me with some 'less than ideal' soft spots in the image. If I try to blend back in some of the layers that have been processed in Auto-Blend, that there are blocky brightness levels in the layers, even after deleting the associated layer mask for that layer.

To get around that I merge all the layers down to one image after the Auto-Merge and delete all but the blended layer. I then save the PSD and reopen it, along with all the original images, in layers. Another Auto-Align and I can blend back in to address the soft areas without the blocky off-brightness look.

I am hoping to test some of these image sets with several of the trial versions suggested by Al, Glenn, and Dan, but I will be away starting next week so it will have to wait until I return.

[FrankMi]

Hi Graham, I'm not sure that there is an effective way to clearly show what is resting on a reflective surface and the reflection, which is at a different focal length, sharply in the same resulting image. You can focus on one or the other in any single image but unless you pixel correct each layer I suspect that you'll get one or the other - or blend where you use a 50% opacity for each, which leaves both somewhat unclear.

Perhaps someone out there has a technique I haven't discovered as yet. If anyone wants to play with this, you can use a mirror with a very small object resting on it. Get in close to the mirror with the camera, and make sure the reflection comes from some distance away. It will be setup correctly if there is a significantly different focal point needed to focus on the reflection than is used to get the small object sharp.

[Glenn NK]

You can download a trial version of ZS at the site referenced earlier in this post. (BTW, I'm not affliated with ZS in any way, and I'm still using the 30-day trial version... just impressed with a good product, and thought I would pass it along. Worth considering, IMO).

Thanks for this - I DL'd Zerene last night and compared the images with those from Helicon.

I thought that Helicon was quite good until I tried Zerene. Zerene seems much better for my flower shots - no ghosting with Zerene compared to Helicon. Helicon seemed a bit better than CombineZ for ghosting, but Zerene seems to work best for me. I've only ever tried stacking for closeup/macro work.

I can't comment on CS because I don't have/use it, but the stacking process in Zerene seems much easier than the process in CS.

On a related note, Ben_Egbert started a thread on dpreview about stacking for landscapes (if anyone is interested):

http://forums.dpreview.com/forums/re...ssage=40384729

Glenn

PS - I'm not affiliated with ZS either but have been using stacking for about five years. Many of the flowers in my link were done with CombineZ.

PPS - thanks to Frank Miller for starting this thread on focus stacking and to Al (snarkbyte) for mentioning Zerene.

[Snarkbyte]

Just thought I should mention that Zerene has some tutorials on their website regarding how to use their product, and these are very much worth watching/reading (some are video, others just text). The two algorithms in Zerene Stacker have different strengths and weaknesses, and best results are obtained by using both these methods in combination, as explained in the tutorials. The ZS application has a "retouch" functionality that allows the user to combine the results of the two methods to obtain the best final result.

[DanK]

Glenn,

I do lots of flowers with Zerene. What I have found is that in many instances, DMap does better with flowers. It supposedly preserves slightly less detail than PMax, but it does considerably better, in my experience, with the delicate color balance and textures that are often critical with flowers. Also, stacking can sometimes cause false specular highlights on textured surfaces, and DMap does that less. On the other hand, if you have big distance front-to-back between adjacent parts of the image, I have found that PMax sometimes creates less haloing.

I sgree with Snarkbyte that the tutorials are very helpful, particularly for learning how to use retouching. However, it is not always the case that combining images from both processes works best, at least in my experience. I think the designer chose a case where it does, in order to show that you can use a composite rather than a single image as a source for retouching. I have combined from a second composite a few times, but most often, if I have doubts, I stack both ways, pick the better of the two composites, and go from there.

I'll post one I did recently with DMap. I think it was about 5 images.

Dan

[Glenn NK]

Glenn,

I do lots of flowers with Zerene. What I have found is that in many instances, DMap does better with flowers. It supposedly preserves slightly less detail than PMax, but it does considerably better, in my experience, with the delicate color balance and textures that are often critical with flowers. Also, stacking can sometimes cause false specular highlights on textured surfaces, and DMap does that less. On the other hand, if you have big distance front-to-back between adjacent parts of the image, I have found that PMax sometimes creates less haloing.

I sgree with Snarkbyte that the tutorials are very helpful, particularly for learning how to use retouching. However, it is not always the case that combining images from both processes works best, at least in my experience. I think the designer chose a case where it does, in order to show that you can use a composite rather than a single image as a source for retouching. I have combined from a second composite a few times, but most often, if I have doubts, I stack both ways, pick the better of the two composites, and go from there.

I'll post one I did recently with DMap. I think it was about 5 images.

Dan

Dan:

First off, that is a very good image - well done.

Thanks very much for the valuable information (and to Al too). I'm convinced that I will go to Zerene.

One question to you two: which version are you using?

Glenn