Luminous Landscape Forum
Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: Transposure on May 01, 2014, 09:51:30 pm
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Hi Guys,
I wanted to start a topic about the use of the RZ67 (RZ67 Pro IID in my case) and solutions to achieve quick focus.
For background, I am shooting people (models) primarily. My main kit to do this is a Canon 1Dx and its AF engine is absolutely superb. I can achieve focus and release the shutter on a moving model in less than a half second. I have the camera set up with back button focus and the rear dial selection of a focus point around an sequentially chosen oval configuration. Rock solid, and the subject's eyes in every capture is in focus, period. Well, let's say 99.9% are in focus, just to be realistic. LOL
I also shoot with the Phase One 645 DF+ with a digital back and it requires focus>reframe, focus>reframe, etc. I have been speeding up my dexterity with that format and can achieve focus in about 2 seconds using the focus>reframe methodology. My "in-focus" percentage is less, let's say about 90-95% depending on ambient lighting.
I have hung the digital back on the RZ67 ProIID and I really like the results of the lens and back configuration, most especially when shooting at f2.8. Without getting technical, I surmise the larger image circle, and corresponding left-weighted positioning on the MTF chart for a given lens, is one of the reasons the rendering is to my liking. I have two Mamiya left hand grips (articulating and fixed) and hand holding is not a problem from a weight perspective. But, achieving accurate focus of the eyes is not easy, at all. I have also used a monopod with similar results. Also, I should note that I have the Mamiya brand spilt prism focusing screen installed, but the split prism is TINY, and largely useless. I use the RZ with either the waist level viewfinder or the prism.
So, since I like the bokeh and rendering of the RZ67 glass, I want to see what solutions others are using, if any, to achieve a quick, sharp, focus of people that are not necessary sitting "statue" still on a stool posing for an old-fashioned portrait. With this request, I want to set a few guidelines so the comments are meaningful...
- Aperture is f2.8
- Focus needs to be achieved within 2 seconds
- Handheld or monopod only, no tripods
- Subjects are people and will pause in their posing for a moment and would not ordinarily hold a pose indefinitely for me to focus
- Loupes are not an option for fast moving subjects
As an aside, I remember talking to an employee at B&H Photo a while back and he told me he loved using his RZ67 and could focus on the fly effortlessly. I was intrigued, in a bit of disbelief, and yet wanted to know his secret.
So, please share techniques or advice!
Thanks!
Ken
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I use an RB67 with a P45 and have to say focusing has always been a problem with it for me.
I have tried to use a prism finder with magnifier, which makes it heavy and awkward to use hand held.
I have used the chimney without much success and I am back with the waist level finder, and have come to the conclusion that it needs a lot of practice.
The main thing is distinguishing between it being in focus and being almost in focus.
Sorry that it's not much help.
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Having shot with both the 1DX and RZ67 II w/MFDB, I would say that you've set yourself a lofty goal.
With the RZ67 shot wide open, I found it was easy to see focus misses of just inches, even at a subject distance of 10 feet. The glass is wonderfully sharp with a great rendition, but I found it took a high degree of precision for focusing. I ended up using a 6x loupe directly on the focus screen through the waist level finder, but obviously this won't work for your purposes.
I'd look at getting the best possible focusing screen (maybe a brightscreen or a maxwell?), perhaps adding a flip up finder magnifier to your prism, and practicing a lot. That, and learning to be okay with a lot more focus misses. :)
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As an aside, I remember talking to an employee at B&H Photo a while back and he told me he loved using his RZ67 and could focus on the fly effortlessly. I was intrigued, in a bit of disbelief, and yet wanted to know his secret.
The secret is not to look at what you want in focus and turn the focus knob until it is acceptably sharp, but to turn the knob, observe how the plane of focus is moving across the image and place it where you want. Or pre-focus and follow the subject.
Still: on 6x7 and f/2.8, that is going to be hard.
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he loved using his RZ67 and could focus on the fly effortlessly. I was intrigued, in a bit of disbelief, and yet wanted to know his secret.
So, please share techniques or advice!
Thanks!
Ken
Love that. Sounds like one of those western fables - "He could shoot blind folded holding the pistol upside down while lighting his corncob pipe and dancing the 2 step, and nail a rabbit a mile down the road".
There are only 2 possible answers to his "secret":
1) Film
2) He wants you in his fan club
My advice? Do it a lot.
And by saying "Do it a lot", I'm not trying to be cheeky, I just mean that with all the cameras we have at our disposal, there are variances in how easily we can produce accurately focused results. What certainly helps is to shoot a lot with a camera - especially one that is a challenge to focus. Often there is compensatory information you gain in how to adjust or compensate for those challenging cameras the more you use them. It can sometimes take a while to get a handle on that. Different focusing screens can have an impact as well - I'm sure some guys will chime in on that, as I've only used the standard gg.
Steve Hendrix
Capture Integration
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Which lens are you using? Distance to subject? Wouldn't stopping down a bit to get more DOF resolve your problem?