Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: narikin on March 16, 2017, 09:39:48 pm

Title: Time delay on XF focus stack exposures?
Post by: narikin on March 16, 2017, 09:39:48 pm
Hi all - is there a way to set a time delay on each focus stack exposures on the Phase One XF?

I'm a little concerned that the focus jumping at each point causes a slight vibration or resonance in the camera, so wanted to dial in something like a 2 or 3sec pause between ES releases. I have found how to set the ES to have a time delay in itself, but not when coupled with the Focus Stack function - is there something I'm missing? (am using IQ3100)

Thanks!

Title: Re: Time delay on XF focus stack exposures?
Post by: Doug Peterson on March 17, 2017, 09:56:38 am
Yes, in the focus stack screen in the top left you can enter a menu that currently only has one option "Delay" and select between 0.5 and 10 seconds.

Less intuitively, but more powerfully you can also exit the Focus Stack screen and engage the Vibration Delay mode as shown in our XF Focus Stacking Webinar (https://digitaltransitions.com/focus-stacking-webinar-recording-now-available/). This is my preference as it does continual monitoring of vibration, whether it is being generated by the body (i.e. your finger pushing the shutter release, the focus mechanism moving) or external (e.g. someone walks by a few feet away on a wooden floor) and delays the capture as needed (but only as needed).
Title: Re: Time delay on XF focus stack exposures?
Post by: narikin on March 17, 2017, 11:36:56 am
Thanks Doug.

I'm surprised how useful focus stacking is even for regular (static) shots. You can work at optimum aperture for resolution, but still get what you need in D-o-F.  what I don't enjoy is having to learn all the variables in Focus Stacking software! Or the large number of image files generated!


Title: Re: Time delay on XF focus stack exposures?
Post by: Doug Peterson on March 17, 2017, 01:37:58 pm
what I don't enjoy is having to learn all the variables in Focus Stacking software! Or the large number of image files generated!

If you haven't watched our webinar (linked above) I'd suggest it for the first ("variables in focus stacking software").

Do note the new Diffraction Correction works very well, allowing you to get between 2/3rds of a stop and 1 stop worth of stop down for "free" (that is f/13 looks a lot like f/9 once diffraction correction is enabled). That can help moderately reduce the number of images required for a given stack (e.g. from 5 images to 3).
Title: Re: Time delay on XF focus stack exposures?
Post by: narikin on March 17, 2017, 02:10:42 pm
Good point. I looked at the diffraction correction option, but was a bit put off when I learned it was a special form of sharpening being applied, when I don't really want to add sharpening till the  very end of my processing pipeline.  I could be wrong or misunderstanding this process option - most likely I am! - but that was my take away.
Title: Re: Time delay on XF focus stack exposures?
Post by: Doug Peterson on March 17, 2017, 02:33:43 pm
Good point. I looked at the diffraction correction option, but was a bit put off when I learned it was a special form of sharpening being applied, when I don't really want to add sharpening till the  very end of my processing pipeline.  I could be wrong or misunderstanding this process option - most likely I am! - but that was my take away.

I agree most sharpening should be usually done at the end of the pipeline (at least when quality is a higher priority than workflow speed).

However deconvolution is not quite the same as a USM. It uses knowledge of the specific type of blur that occurs with a given lens-aperture combination (the point spread function) and attempts to restore the signal to (closer to) it's original state.

I can't tell you if it's right for your specific needs, or if another workflow would be better. But I do feel strongly it's worth looking at to make that determination yourself. In my bodyscape (https://www.instagram.com/terranudum/) work I've already increased the aperture I feel comfortable working with by a full stop as a result of Diffraction Correction, which sounds small, but every stop really helps!