Canon: Big and Small steps?

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mike_mccue
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Canon: Big and Small steps?

Post by mike_mccue » 23.04.2015 13:36

I've read the entire manual but am hoping for some clarification regarding the Canon Big and Small steps options in the Helicon Remote>Preferences>Canon dialog.

How does this relate to the step size in the focus bracketing panel? If the interval is one step in the focus bracket panel how does the choice of big or small effect the the relative number of steps the stepper motor moves?

Thank You.

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Stas Yatsenko
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Re: Canon: Big and Small steps?

Post by Stas Yatsenko » 23.04.2015 14:44

With small step size you will need significantly more steps to cover the same focal distance. Use small step for macro or micro shooting when you need higher focus movement precision.

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mike_mccue
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Re: Canon: Big and Small steps?

Post by mike_mccue » 23.04.2015 15:52

Thanks Stas. I am primarily interested in using remote for photographing flowers so I'll give small a try.

I was already shooting in increments of "1" in the focus bracket panel. Is the Big and Small factor a multiplier of the increments displayed in the focus bracket panel?


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mike_mccue
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Re: Canon: Big and Small steps?

Post by mike_mccue » 24.04.2015 22:45

I made some comparisons today between the use of Big Steps and Small Steps while using a Canon 5dmkII and Canon 180mm Macro lens and it seems as if the difference between the two is approximately a factor of "10". In other words 1 Focus Bracket "Increment" of a big step seems to equal 10 Focus Bracket small step "Increments".

I think the result with the small steps seems noticeably sharper than the result with the big steps.

I uploaded a 2 layer .psd file as an attachment so people can take a look and form their own opinions... but when it got to 100% upload it seemed to vanish. :(

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Stas Yatsenko
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Re: Canon: Big and Small steps?

Post by Stas Yatsenko » 30.04.2015 10:02

You would only get better result with small step when the big one is actually too big for your setup, i. e. your actual DOF is less than 1.0 big steps.
You're better off uploading the file on a file hosting (Dropbox / Google Drive etc.) and posting a link here. We've had to set pretty restrictive file uploading settings on the forum.

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mike_mccue
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Re: Canon: Big and Small steps?

Post by mike_mccue » 04.05.2015 17:06

Hi Stas,
Thanks for the information.

I made a .jpeg of a full view and two cropped .jpegs showing the details to provide an opportunity for comparison between a stack made with 10 big steps and 100 small steps. Both examples were shot with the very same ISO, shutter speed, and aperture settings. The raw files were converted to .psd files without any sharpening in Adobe Camera RAW. The jpegs were saved at 100% quality.

You may notice that there is a shifting parallax effect when comparing the two stacks. You may notice that the stack made with 100 steps has sharper detail.

One thing that I found interesting is that you could see, as the stacks were being processed, that the edge lines in the black and white display were more discrete and seemed for lack of a better word, more "select". It seemed as if Helicon Focus selected less data from each frame when it had more frames to work with and that this process resulted in a sharper image. It seemed as if Helicon Focus was more effective at identifying the most pertinent detail when it had more frames to work with.

I think the results of the big steps are very good but it seems as if the results of the small steps are even better.

Full Frame:
10-big-steps-vs-100-small-steps.jpg
Full Frame showing crop area
(354.16 KiB) Not downloaded yet
10 big steps:
10-big-steps-crop.jpg
10 Big Steps cropped
(489.1 KiB) Not downloaded yet
100 small steps:
100-small-steps-crop.jpg
100 Small Steps cropped
(544.73 KiB) Not downloaded yet

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Stas Yatsenko
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Re: Canon: Big and Small steps?

Post by Stas Yatsenko » 06.05.2015 11:06

I do not see much difference between those images. I think both big and small steps provide good overlapping of focused areas. Which means that the program has enough information to construct the result.

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mike_mccue
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Re: Canon: Big and Small steps?

Post by mike_mccue » 07.05.2015 03:00

An easy way to inspect the difference between the two examples is to open each in a new tab of your web browser and then switch from one tab to another. This works as well as if the two examples are stacked as layers of a Photoshop file so that you may quickly swap between layers.

This sort of direct comparison provides an effective opportunity to consider whether the big steps are good enough or if smaller steps will help you get the best results.

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