NikonGear'23

Gear Talk => Camera Talk => Topic started by: Michael Erlewine on August 06, 2020, 17:36:10

Title: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: Michael Erlewine on August 06, 2020, 17:36:10
Focus stacking (with its layers) wants to be aligned properly. With heavier equipment (like view cameras) and odd angles of inclination for the camera in order to get the shot we want, the sheer weight of the bellows, lens, etc. can at times put stress on the focusing device, making it not always advance smoothly, and its movement causes vibrations..

Quite often, I have to wait for the movement I just made with the focus knob to stabilize and the slight jitter to die down.

I use the Nikon Z7 or Nikon D859. And I wish Nikon would allow me to magnify the object, take the photo, and return to the magnified view. Yet, of course, Nikon does not allow this.

Yet, in magnified view I can clearly see if there is any shimmer in the object, but it is very tedious (and adds further shakiness of its own) to continue to press the magnified view, just to see that shakiness is gone.

And so, a great work-around is to simply add a small bubble level to the hot-shoe on the camera (or wherever). It is very easy to keep an eye on the level and see where there is shakiness and watch it die down. Works perfectly. I can advance the focus steps and keep my eye on the bubble-level and see exactly when there is no longer any movement.

I realize this will interest about zero of you reading this, but there may be a soul or two who stack focus who have not yet found this very helpful tip.

Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: PeterN on August 06, 2020, 18:47:24
That is a creative solution! BTW, I always find your posts interesting! So this one as well. I do focus-stacking but use easy to use lenses such as the Nikon 60mm, 85mm pc-e and Zeiss 135mm. When using an AF lens, I use the auto focus stacking function and when using the manual focus lenses I try to turn the focus ring slightly. I tried a focus fail but for an unknown reason I do not like using one. Probably because my standards - and consequently the outcomes - are much lower than yours. However, I do use the electronic shutter, a remote release, and a exposure delay of 3s to eliminate shake. That works for me so far.

Thank you for posting!
Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: pluton on August 06, 2020, 19:49:42
I can foresee other vibration-sensitive shooting scenarios where this bubble level solution might be helpful.  Thanks for posting the idea!
Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: ColinM on August 06, 2020, 20:22:30
If the vaccine research teams had access to your patient, systematic approach to problem solving, they might be closer to a solution Michael!.
Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: Michael Erlewine on August 06, 2020, 22:51:50
The vibration comes from turning the focus rail, not from the camera, especially when the view camera is tilted and the load exerts more weight.
Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: Birna Rørslett on August 06, 2020, 23:46:33
Running the process as automated as possible, introducing long time delays, and of course good approaches to sufficient camera suppoirt will help a lot. Thus, preferably no manual intervention at all, which is a breeze to set up using for example the Cognisys Stackshot controller.

I use various Nikon Multiphot setups, the device being built nearly 50 years ago in an era in which the concept of 'quality' meant something. They are very heavy (10-20 kg depending on the setup), dampened by rubber feet, and the support structures are truly massive. Put a Z camera with electronic shutter on such a foundation and vibration is the least of one's worries. To further finetune the setup, the Multiphots reside on a massive table itself weighing nearly 200 kg.

When the magnification increases, it can be beneficial to move the subject not the camera. That approach solves a lot of problemes on its own (and introduces others, TANSTAAFL).

A laser pointer will indicate movement as an alternative to the bubble level.
Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: Michael Erlewine on August 07, 2020, 02:24:42
A small bubble-level, which most of us have around, is a simple, lightweight method to visibly see whether the system is shaky or not. That was my point.
Title: Re: Focus-Stacking: Waiting for the Vibrations to Die Out
Post by: Birna Rørslett on August 07, 2020, 06:49:49
True enough. I added the laser pointer because it indicates movement more clearly. And the bubble level is valuable on its own when the camera has to be levelled.