Focus stack issue

[sanfairyanne]

This is a 100% crop of an image I focus stacked with a group of 5 images. I bought Helicon Focus software and it creates this issue. What you see in the image is a natural sandstone arch, the software seems to struggle with the edge of the arch, I imagine it's confused and can't define what is the arch and what is the background.

I've tried doing it via the automate feature in CS5 but that can't cope either.
I suppose I should learn to do it manually in layers.

Any ideas/advice would be much appreciated.

[Tony Jay]

My information is that this is a known issue with Helicon Focus.

However I do have a question: How did you plan the various focus points? Did you use Helicon remote or some other automated solution or was this done "manually"?

The reason I ask is that how you chose your focus points can contribute to the highlighted issue.
BTW my facility with Helicon Focus is still a work in progress so I am not yet an authority.

Regards

Tony Jay

[Dward]

I've had better luck with Zerene Stacker.   It finds edges and leaves no artifacts that I can see.

 Both programs are excellent, but Zerene is cheaper, and I find it can sometimes stack successfully where Helicon doesn't (and vice-versa.

David V. Ward, Ph. D.
www.dvward.com
David V. Ward Fine Art Photography

[sanfairyanne]

Thanks I'll take a look at it.

[sanfairyanne]

Oh sorry I didn't see the other reply. I did my focus points manually actually I couldn't get my eye to the viewfinder so I just hoped for the best one or two attempts I didn't even focus far enough. Thankfully I shot this many times, I used an entire 5D2 battery on this one shot.

[bill t.]

Not sure what I'm actually looking at in the example.

But Helicon and I think also Zerene give you the option to edit various of the stack elements with something like masks.  You can specifically select only parts of the image from a specific stack member.  This often helps remove ambiguities, "cloud echoes" and such areas where elements of two or three neighboring stack members are entwined inappropriately.

[sanfairyanne]

I just tried Zerene, good god it's slow. I started with Tif files but then reduced Jpegs down to less than 1mb a file even with just 7 files its takes something like 10 minutes. I'm getting messed up with it, I get to the bit where it produces an image but when I saved it there isn't a result in that folder rather a bunch of aligned/unaligned images.

I don't suppose anyone has much idea where I'm going wrong with this it's getting tedious.

Thanks

[Bart_van_der_Wolf]

Any ideas/advice would be much appreciated.

Did you use method A or method B? Method A is better at getting surface structures, and Method B is better at edges, although occluded edges require the selection of the proper focus planes. The Pro version allows to retouch by using the details from certain focus planes.

Cheers,
Bart

[sanfairyanne]

I'm not sure, I will re-do it in Tiff and try it in both to compare the results. Thanks for the advice I had no idea what was the difference between the two.

[Tony Jay]

I did my focus points manually actually ....

It can be very hard to be sure that one has accurately overlapped acceptable focus in all areas.
Helicon sells a utility called Helicon Remote that is very useful in this regard.
It does require tethering to a computer though.
What one does is show the software the near and far limits of required focus.
The software detects the lens focal length, f stop etc and can then precisely calculate the focusing intervals required (these are not like regular fence posts but closer together the closer one is to the camera and further apart as one moves away from the camera).
The software will also control the camera and execute the series of shots appropriately.
Helicon Remote will also do HDR sequences, either in isolation or in combination with the focus stacking.

Another possible solution is the Promote Control programmable remote (useful where tethering to a computer is impractical).

Although accurate shooting may not completely eliminate the possibility of artifacts it does give the software the best possible starting point.

Regards

Tony Jay

[sanfairyanne]

Wow that Promote Control really looks amazing and it's not much more expensive than the Canon Intervalometer. I'm intrigued as to how it adjusts focus. I'll contact the company. One thing that's alway struck me is why don't the manufacturers build this into their cameras. I mean having to use the intervalometer to do time lapse etc is plain daft, I'd ditch Jpeg in camera for that any day of the week.

[Tony Jay]

Wow that Promote Control really looks amazing ... I'd ditch Jpeg in camera for that any day of the week.

Yes, it does have its uses all right.

BTW, the website is fairly comprehensive and if my memory is correct there are also several videos demonstating its operation floating about on the net as well.

Regards

Tony Jay

[sanfairyanne]

Yes I've just watched one, I'm putting in an order ASAP. I just finished a 5 month shoot in the American Southwest I wish I'd got this at the start of the trip.

[Tony Jay]

Good luck with its use.

I haven't used it for its time-lapse abilities yet but am very much looking forward to experimenting doing time-lapse star trails and reconstructing them as stacks.
The result should be indistinguishable from a single long exposure except for the absence of noise (a fantastic side-effect of the post-processing stacking).

Regards

Tony Jay

[sanfairyanne]

Tony,

I wanted one good star trail on my website and so I stacked about 50 images in CS5 (automated) it's certainly less noisy though it probably helped that I was shooting in negative fahrenheit conditions as that reduces noise in camera.

[Tony Jay]

How long were the exposures?

Regards

Tony Jay

[Alan Smallbone]

The Promote Controller works great for a lot of uses, especially timelapse, where you can do hdr timelapse, as well as normal timelaps, it will also calculate hyperfocal settings. The hdr function allows the user to define the number of frames and spacing in EV. The focus stacking works by setting the start point and the end point, then you tell it how many shots and it figures out the steps and takes them. You can set the step size, although the default works fine. The latest version of the firmware, still beta, will do bulb ramping, which is nice when you are doing timelapse. Well worth the money in my opinion. Automated focus stacking only works on lenses that can autofocus.

Alan

[bill t.]

Blast!  That my unloved Promote can now do focus stacking with those intractable autofocus lenses in muddying my decision to pick up a D800 to replace my present 5D2.  Apparently Promote focus stacking works with Canon only.  If the focus sequencing is truly repeatable it will be a major blessing for us stitchographers.

[sanfairyanne]

Sorry for a late reply I got held up in the airport. Tony my star trail shots were about 45 seconds it's here if you care to look at it:
http://www.flickr.com/photos/andrew_waddington_images/6049592779/in/photostream

It's really easy to do you just get a decent exposure and go for it, the one thing I notice is that because you have a minimum of a 1 second gap between exposures you actually see this as a gap in the result. Someone recently gave me a Photoshop script to combat this, however, I've not bothered with it, I mean who really notices that gap anyway. I used my 16-35L lens probably at about 17mm at around f5.6.

Can anyone explain what is bulb ramping?

[Tony Jay]

I have to confess I have never encountered the term "bulb ramping".

Thanks for the insight into your star trails.
BTW there is a fantastic star trail posted on LuLa in the last day or so under Moonrise over Manaslu.

Regards

Tony Jay