Focus Stacking, CS4 & Helicon Focus

[Dave_Anderson]

I took a series of macro shots that I wanted to use try my hand at focus stacking. Obviously the best way to do this would be to use a focus rail and tripod on a perfectly static subject, but since that's not always possible I decided to do a test under non-optimal conditions. I went ahead and took the shots of a flower handheld. The shots were nothing special but I've spent a few hours today just playing and trying to get my head around the process. I ran into some significant stumbling blocks and figured I'd see what others think about alternatives, workarounds, etc.

First off, I tried using CS4 since I already have it. I started with 6 16-bit TIFFs, ~24.6MP ea. System is an XP quad core 3.0 with 4G, lots of free HD space(~1.8TB) on my scratch drives. CS4 happily loaded the 16-bit TIFF files(6) into layers and auto-aligned them very well, considering the flower was swaying a bit. Unfortunately, when I tried to auto-blend the layers, CS4 ran out of RAM. After many experiments, restarting CS4(and XP) multiple times, etc. I found that auto-blend would work if I started with 8-bit TIFF or jpeg, cropped away the edges to where all images went to the edge of the canvas then reduced the image to 30%. Not especially encouraging, but it actually did a pretty nice job of blending it all together. Allowing CS4 to use more RAM, up to its maximum, didn't seem to help much.

I DL'ed a trial of Helicon focus and it swallowed up the 16-bit tiffs just fine but left a lot of artifacts around the edges, apparently due to movement. I tried exporting the CS4 layers as individual files after aligning and cropping, and ended up with slightly better results. I tried setting the alignment parameters up to 20 to see if maybe I had been limiting HF's ability to align, but it just crashed.

Tomorrow I'll try some captures for stacking using the bellows, since that's the only focus rail I have that's geared; I do have one on the way I can use without bellows.

So, question for the group, what have your experiences been with focus-stacking large files, with these tools or others?

 

[Jack]

With HF, the routine and mask settings matter. You might want to experiment with them.

In preferences, try setting resample method to Lanczos 3 and depth map feathering to 4. In focus parameters, try adjusting the radius and smoothing. Minor changes here can make a big difference in the final output. You can also edit the masks manually as needed if you have problem zones. Finally, remember, that the finer the focus changes between frames (meaning more total focus frames) the better then end result.

 

[Don Libby]

Finally, remember, that the finer the focus changes between frames (meaning more total focus frames) the better then end result.

I normally look at focus stacking with no less than 3 images; near, in-between, and far then depending of the location will add anywhere from 2 upwards to 4 more. It's not uncommon for me to have a range of 5 to 7 images for stacking. I once shot an image over 12 times changing the focus every 1/2 meter till I got out far enough and shot a couple for infinity. Shoot more than you think you'll need so you'll have enough.

HF is great for when you have movements such as windy conditions.

Don

 

[Dave_Anderson]

Thanks for the encouragement, guys. I played with it a bit more and for a while I was having issues with application errors, exceptions, etc. Also, when I tried to select an image in the retouching pane it would tell me it couldn't find the image...

Thinking that I was maybe expecting too much, I thought it over a bit more and decided that I didn't really need to use 16-bit since by the time I am in HF I should have made all of my corrections such as dodge/burn/ND grad/WB/etc. and in HF all I am doing is selecting parts of each image in the stack to go into the finished image. IMHO changes post-HF would be primarily just cropping and sharpening.

I re-exported the files as 8-bit rather than 16-bit TIFF and suddenly it all clicked. I was able to select images in the retouching pane, show masks, clone/copy/etc. with no issues other than the (expected) short delay as I selected different source images. I need to play with it a bit more before I fully understand how to manipulate masks.

So, on to the results. As I said, nothing special here, I was just goofing around in the back yard with my 100 2.8 & ringflash, and the thought of playing with focus stacking popped into my head.

First, here is a GIF that shows the stack. This was handheld, the flower swaying a bit in the slight breeze, and the point of focus does not progress smoothly as it should when stacking. I wanted a difficult test, and I got it.

Here is a larger pic of one of the images in the stack to better illustrate the DOF I was working with at f2.8:

This was my first stack, Method=B Radius=8, Smoothing=4. Of course I would have cropped away the left side, and the halos were especially problematic since HF would not allow me to select individual files on the retouch pane while working with 16-bit TIFFs and I was essentially missing out on the functionality I needed to fix it.

For this stack, I had CS4 handle the alignment step, cropped away the outer area where the images did not overlap, and saved each layer out as an 8-bit TIFF. Working with the smaller files made the full range of features available to me. While I did not try them all, I worked with enough to see that the potential is there to get very good results -- in this case limited by the sloppy capture. I had to stop myself; IMHO this particular photo is not worthy of heroic PP efforts but it served well as an experiment. It seems to me that if I am very careful with alignment and focus steps HF can give me excellent results.

I will contact Helicon about the large file issue and see what they say. I prefer to use maximum resolution/bit depth until the very last moment when I convert to JPEG but all things considered I don't think that's a deal-killer.

And, just for kicks, here is a 1:1 macro of some of the very tiny flowers we have. The ringflash is much better-suited for very close focus on very small subjects. I'm going to figure out some sort of bracket/diffuser setup for larger subjects.

I don't know if I'll be able to get to my experiment with bellows today... the honey-dos are piling up.

 

[Dave_Anderson]

What's MK1 Focus? Is this related to Helicon Focus?

I've been meaning to get back to this, but the holidays have been a bit crazy. Also, while I did get a focus rail that I can use without bellows, I was waiting for Santa to bring the lighting goodies that I want to use for this. I have a a number of goodies I brought back from India and will use them as test subjects.

One thing to experiment with, since the largest subject will have a bit more than a handspan taking up the frame, will be using the focus ring on the lens to change focus vs using a rail. I'm afraid that with the large subject, the perspective shift from using a rail might be an issue.

 

[Dave_Anderson]

Well, the original post #5 in this thread has disappeared... maybe it was spam? Anyway, disregard the first line in my post #5 above.

I finally received a response from the Heliconsoft folks, they suggested that I add a "/3GB" switch to my boot.ini file per this PAE document on Microsoft's WHDC site.

This resolved the issue with HF and large 16-bit TIFFs. Moreover, this change allowed CS4 to see nearly an additional GB of RAM, and it proceeded much further in the auto-blend process, almost completing before it ran out of RAM. I cropped the auto-aligned layers as before, reducing the file size from about 940MB to about 670MB, closed and re-opened CS4, and this time it succeeded in auto-blending all of the layers. The result is below.

This is saved out as JPEG immediately after the auto-blend. This came out far cleaner than the HF result(below); it's a pity that CS4 does such a poor job of making use of virtual memory in cases like this. I realize that I can get better results with HF than the example below through more careful shooting and judicious use of the "retouch" feature, I just wish it were as smart as CS4 in terms of automation and minimizing manual steps.

Heliconsoft has a discount ending 12/31/09, hopefully they will answer my last pre-purchase question before then. It's not clear from their order page whether I need the pro version to enable PAE; this seems to be the case but I want to be sure before forking over the extra $$$.

 

[Dave_Anderson]

[RANT]
:angry: :cussing:
I contacted Helicon Focus on Dec 7 with questions about the problems I was having. I pinged them again on Dec. 26, since I had heard nothing. I received a message on the same day, saying they would get back to me on the 30th. On the 30th, they finally answered part of my question, but not the question about which license would give me the most usable RAM address space(It wasn't clear from their description that the x64 version would do this). I finally received an answer to that this morning, then went to their site and the discount that was supposed to be effective until 12/31 is no longer available.

:cussing:

[/RANT]

OK, I found it at the discounted price here. Successfully purchased and registered at the discounted price. Now to get some captures...

 

[Dave_Anderson]

Well, I'm back, having shot some pics with much more care, with "intent to stack". The main capture that I wanted was the beautiful bone handle & silver inlay on a sword that I brought back from India when I visited in 2007. While I was at it, I took some pics of some boxes that I picked up in various parts of India; most from Bangalore but the two marble boxes I purchased in Agra. Backdrop is a cashmere blanket that I picked up in Old Bangalore; it turned out a bit busy so I may re-shoot using another backdrop but my initial intent was to have everything in the frame be something that I brought back from India. One thing I may try is to use blurred portions of the stack for the blanket so that the sword is the only thing sharp in the frame. The possibilities are endless!

When I was there, the only digital camera that I had was a 4MP P&S; I would love to be able to go back with my DSLR but that's not in the cards at the moment. We'll see what the year ahead holds.

All pics taken with a900 & Minolta 100/2.8 Macro(original) at 1/100 f8, ISO 200, lit by a shoot-through umbrella just outside the upper right of the frame and a piece of paper folded in the middle to act as a free-standing reflector on the left. MF, MLU, cable release, UniWB ETTR.

So, cutting to the chase, here is the finished product:

I used edge sharpening in CS4, Topaz Denoise on the unsharpened areas. I also boosted clarity by about 8 and saturation by about 5 on all of these shots, and played with the curves to richen up the tones. Below is a 100% crop of an area where the bone handle appears to have been repaired(or perhaps it was made this way, all of the seams appear to have the same sort of glue), also showing a spot where the silver inlay was spliced.

Here is one of the original captures, showing how narrow the DOF is even at f8, also by comparing this with the above you can see the extent of the PP.

Here's an interesting feature of Helicon Focus, you can show a 3d map of the stack which helps evaluate how consistent your steps were. At least, that's what I found it useful for -- it may have other uses. Considering that I shot this nearly in the dark, using a maglight to focus(didn't want ambient tungsten light in the frame), the steps were remarkably consistent. However, looking closely at the result, I should have made the steps at least 1/3 smaller since there is slight blurring at the edges of each stack. This is not really visible unless you know where to look, at least not on the SmugMug-resized images up to X3Large. It may be visible in a large print though; we'll see.

Here are the other captures from the same session. The brass boxes were typical handicraft items available at any number of shops, the marble boxes were made using the same translucent marble as was used to build the Taj Mahal(available nowhere else in the world, apparently), the semi-precious stones were inlaid allegedly by descendants of the artisans that did similar work on the Taj and using the same glue/process that has held up for centuries on the structure. I had an opportunity to see the artisans at work but they didn't want me taking pictures. Everything is done with hand tools, the wheels they use to lap the inlays to shape are spun by hand.

This shot shows some slight fringing that I didn't take the time to clean up; visible in the crop below. The sword came out so well that I just batched the next two stacks. Lesson learned, you have to pay attention at every step, with every image.

Again, one of the original captures:

And the 3D map:

(To be cont'd due to 10-image-per-post limit)

 

[Dave_Anderson]

This lacquered gold-painted box shows my lighting setup all too well. Obviously I need a softbox for highly reflective subjects, and I need to take more care with light placement so that the reflection of the light source doesn't take over:

And a crop, showing that here too fringing needs some tweaking to processing parameters and/or retouching.

Again, one of the original captures:

And the 3D map:

All in all, I am very happy with the results; at least I can see the road from here to the results I want. For people considering Helicon Focus, I have the following advice to offer:

• At minimum, get the pro version so that you can retouch and get rid of the fringing when it occurs.
• If you want to stack 24 MP 16-bit TIFFs then you need the Pro x64 version. On 32-bit Windows, it will give you GB total memory address space, on 64-bit windows it will allow you to make use of all RAM in the system plus any virtual memory.

 

[Jack]

Congrats Dave,

It appears you have found a very workable solution!

 

[Dave_Anderson]

Yep, looks very workable.

I should mention, earlier in this thread I mentioned performing some PP on images before stacking. I was doing this because I was having trouble getting HF to handle the 16-bit TIFFs, and recognizing that PP options(especially curves) are limited on 8-bit files I was doing the PP prior to downconverting. For the three recent images above, I converted to 16-bit ProPhotoRGB TIFF with no sharpening, NR or other adjustments, and performed all PP on the stacked TIFF output by HF. This makes for a much simpler workflow and at least in theory should provide same or better end results.