This article comes from a discussion thread
on the DV Info Net community message boards.
After using the Sony Z7U for a few months now, doing some testing as well as real world shooting experience, here are some focus and low light tips tips for newbies and others as well, when using the stock Zeiss lens.
Of course, to begin with, make sure you first do the Lens Flange adjustment, either auto or manual, to make sure you have solid focus through the entire zoom range. Use adequate light (but not too much, you need the lens wide open), camera on tripod, back focus chart that came with the camera on a chair or music stand, both camera and chart at the same height and you are shooting the chart head on (not off to the side). Make sure the auto adjustment is successful or you know what you are doing with the manual adjustment.
When shooting in low light, or when there are hot spots in the background of your frame (candles, flickering lights, mirrors that have light reflections, windows), refrain from using auto focus. Also, turn off the macro focus (in the camera menu). Use one of the assignable buttons if you want to turn it on for closeup work. There are too many focus hunting problems with this camera, while using auto focus and/or macro focus in low light. Instead, slide the focus ring towards the back of the lens and use manual focus. Zoom in tight to the eyes of your subject, focus, zoom out. If your subject’s distance to your lens stays the same, no problem. However, unless you are shooting interviews, toasts, or perhaps a boring dance, this doesn’t happen. Let’s move on…
If the subject moves towards you, and you can zoom out, don’t worry too much about re-focusing. In fact, if you zoom out all the way to the widest zoom setting, you can move the focus to infinity. Everything in the frame will look crisp and clear (except for the macro range, which is within 2.5 feet of this lens). I was surprised about this myself and did another flange adjustment to see if it was out, but everything with my camera and lens is fine. If you want the background to go a bit soft (to take advantage of shallow DOF), don’t set the focus to infinity. Set it to the proper distance or perhaps a bit further, but don’t set it any closer than the distance to your subject, or everything WILL go out of focus.
All of my dancers stay in focus and the background goes a bit soft.
For example, for wedding reception dance shots, I shoot some of my footage while standing on the dance floor with the dancers, and I set the zoom to the widest setting. I then set the manual focus to about 20 feet. That way, all of my dancers stay in focus and the background goes a bit soft (if the light level is low enough of course, which it usually is at receptions). If the dancers move closer to your lens, no problem, they will not go out of focus, I swear, as long as you are at the widest setting on the zoom.
For folks walking towards you during the procession, recession, or guest intro’s, set the focus to the furthest away shot (doorway or pew you want to start filming from). I call this the starting point. Remember this setting. You’ll always see a distance readout in the viewfinder if you use manual focus. I use the foot readout (changeable in the camera menu). When you zoom out, don’t worry too much about being right on, just focus accordingly but DON’T focus forward too fast or you WILL go out of focus. As you zoom out, the wider the zoom, the less out of focus issues. You won’t notice any focus problem unless you remain fairly tight most of the way. In this latter instance, you might have to try auto focus. Just watch out for the auto focus hunting. I set my peaking all the way to high and leave it on all the time (again, in camera menu) to look for the auto focus to go haywire. If you stick with manual focus, remember to go back to the same focus setting you had before when you zoom back in to the starting point.
Basically, once you focus on, let’s say a dance couple, if you widen out, they will stay in focus, either at the distance you set them for, or if they walk toward the camera (assuming you zoom to a wider shot). You won’t have to refocus for them moving closer to the camera. However, and this is important!: if you have accurate focus on the couple but then they move further away from your camera, you will definitely notice them and your whole shot go soft, even if your lens is at the widest zoom setting! You may not notice this under good light, but it just looks terrible under low light.
If you think they’re 10 feet away, set your focus to 15 feet, or more.
Best advice I have: once you focus on your subjects, if you notice them moving back, focus away from you. If they move closer to you, no need to refocus (if you widen shot or your shot is already fully wide). If you want to guess distance in feet while shooting (like I do) do this only when your lens is at it’s widest zoom setting and always tend to focus a little behind your subject. If you think they’re 10 feet away, set your focus to 15 feet, or more. This way, if your subject moves either closer or a bit further away, you won’t notice any out of focus issues.
Low light tips: If you have to use it, I found out that even 12 db does not look bad with these cameras. Early on, my dancing footage had a spot light look to it, due not only to the fact that sometimes the reception was very dark, but also because I used a low db setting on the camera (worried about grain in the image), did not use diffusion on the camera light and I had the light set fairly bright. Now I use diffusion and adjust (dim) the camera light and db settings on the camera depending on the background. I sometimes go with 12db (instead of 6db or 9 db), and dim my camera light accordingly. This way, the foreground lighting does not overpower the dark background. I would rather go with a more natural look, even if it looks a tad grainy. To me, this looks better than going with a lower db setting and having the footage look muddy due to the lack of enough overall light. On these cameras, the more exact the exposure, the sharper the image. Too dark of a room, or underexposed images, make the blacks look muddy and soft, especially in the backgrounds.
Hopefully some of my experience with these cameras will help others. Feel free to add to any of this, if you feel it would be constructive.
Stephen Gradin and his HVR-Z7U
Dockside Video Productions
Two HVR-Z7U’s, One Canon HV-20,
Adobe Production Studio CS3 w/Matrox RT.X2
Stephen has been a professional broadcast and independent videographer and editor for over 25 years. He’s won numerous television awards, including regional Emmy’s for videographer and editing. He holds a BA in Film and Theater Arts from Penn State University, having worked in Public Television soon after college and spending most of his life in the professional broadcast television business. Stephen is now the owner and operator of Dockside Video Productions, a Wedding and Event Videography Company, located in Columbia, Maryland. He presently shoots, edits and produces wedding and event productions in HD.
Text and photos by Stephen Gradin