Focus Bracketing vs automated rail

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pawelfoto
Posts: 76
Joined: Tue Mar 09, 2021 2:51 pm
Location: Poland

Focus Bracketing vs automated rail

Post by pawelfoto »

My first impressions of FB with the canon M6M2 + 28mm Macro lens.
The great photos that Adalbert (ADi) takes masterfully made me buy canon M6 mMark II. I was actually buying dreams that someday I will be able to take beautiful photos like you, ADi. I know that your successes are driven not only by equipment, but also by talent, years of work and patience. Already after the first sessions I can admit that the internal focus bracketing gives a lot of pleasure and opens up new possibilities. So far I have been doing focus stacking with the WeMacro rail. What I like about this method is full control and the possibility of precise adjustment of all parameters. For now, I suppose nothing will replace the automated focus rail at extreme macro. In the case of FB, the price of giving up control over things that happen automatically results in a significant acceleration of work. Thanks to the fact that in several dozen seconds I get several hundred frames, it allows me to repeat the shot in many variants with impunity. This is important to me because I learn from mistakes. Nevertheless, my initial attempts did not go well. Sessions with microscopic lenses plus the EF 70-200 do not go well for me, mainly because it is difficult for me to set the beginning and end of the depth of field, and often automatic bracketing ends too early. The autofocus in my old EF 100mm f2.8 macro (no IS) works like a tractor and I don't get good focus with Raynox. But these are my first steps and I need to work on it. However, I am delighted with the work of the EFM 28mm f / 3.5 Macro STM. The AF motor is quiet and very smooth. In combination with the M6M2, it creates a handy light set, you can easily make even long stacks on an ordinary desk. A fully electronic shutter completes the happiness. For continuous lighting, I use DIY LED lighting based on Epistar SMD-2835 4000K diodes and alternatively 6500K. I am very pleased with the Andoer W64 panels https://www.aliexpress.com/item/1005001 ... 4c4d7Z6ZFP and Ulanzi VL120 https://www.aliexpress.com/item/4001136004035.html?spm = a2g0s.9042311.0.0.1ec64c4d87QNJz. My XHP160 LED flashlights have completely failed, because they automatically dim with increasing LED temperature. https://www.aliexpress.com/item/1005001 ... 4c4dujaJxj Which models are possibly worth recommending? For ease of use, I also experiment with the monitor screen as a background. At 1: 1 and below, you can easily change backgrounds and achieve an effect like a wide angle macro at 28mm.
Back to FB. I set the number of photos without hesitation to 999, and steps (increments) to 1. As during bracketing I see that the camera has reached the end of my subject, I end the bracketing by pressing the shutter again. I noticed that tethering slows down bracketing, maybe because of the usb transfer? I also found a way to set the starting focus point. In the lower part of the scene, I place a pin in front of the model and set the initial AF on it. Thanks to this, I am sure that the front elements that are difficult to catch by AF, such as antennas, will be in the focus range. That pin will be automatically cropped at Zerene anyway. Below is an example. What is your workflow?
== best, Pawel
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Adalbert
Posts: 1444
Joined: Mon Nov 30, 2015 1:09 pm

Re: Focus Bracketing vs automated rail

Post by Adalbert »

Hi Paweł,

Yes, the EOS M6M2 is an excellent camera and is great for stacking.

When I use the EF 70-200L with DCR250 for macro, I focus it at close range to get the maximum magnification.
But when I use the EF 70-200L with a microscope lens, I focus it at infinity to get the best quality.

The M6M2 moves the focus from close to infinity with the internal FB.

For the internal FB, I first determine the range (close for macro, near infinity for micro).
A simple rail can be useful for this.
fb+rail.jpg
Before I start shooting, I use the autofocus to focus on a point that can be caught,
then I hold the shutter button halfway down, change the focus manually (towards close-up on the starting point)
and then finish pressing the shutter button.
Most of the time I use the shutter delay of 2 seconds (sometimes 10 seconds).

Best,
ADi

klevin
Posts: 80
Joined: Fri Dec 14, 2012 5:28 pm
Location: SW New Hampshire, USA

Re: Focus Bracketing vs automated rail

Post by klevin »

I do most of my macro with my 100mm L macro, sometimes with extension tubes, which gets me to about 2x. I also on occasion use a 10x microscope objective on a 55-250 zoom, but not often since I have so much fun with the 100mm. I also have the m6ii.

What I've found is the easiest is to use back button focus or touch screen focus, single point. I focus on the nearest part, then turn the lens barrel a touch closer, so I'm sure to get everything. Then I let er rip.

I had previously calibrated my 100mm vs FB using a focus wedge, and found that the step size varied in a complex way with magnification and f stop. I made a card to help me estimate, so I can be sure to go beyond my end point.

I shoot raw. As soon as pics are loaded into LR, my first step is to delete the ones that are totally out of focus, either at the start or the end. I also found it helpul to set one of the shots black to mark the start of a new stack. Then I adjust exposure etc. as necessary. Finally, I export to jpg and stack using either zerene (thanks Rik) or Helicon. Although Helicon claims to work with RAW, all it does is export tiff and stack those. I found no quality difference, but a big time difference, hence my workflow to jpg.

My shooting is mostly botanicals. Before the M6ii, it was studio work. Now, I try to do the shots in the field, but wind is of course a big issue. Regardless, it's not unusual for me to have a 4-500 shots after 30 minutes of work.

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