Focus and Low Light Tips at DVinfo.net

Stephen Gradin · July 16th, 2008, 02:00 PM

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.

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.

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.

Chad Dyle · July 16th, 2008, 05:12 PM

Stephen,

That was a great explantion of the Z7 for wedding videographers. I moved to the Z7 from an FX-1 and was really nervous about using the camera. After a few weddings and long nights of playing with the camera, I began to learn how it works and just adjusted my shooting style to meet its needs. Its kind of like a new girlfriend, if you don't learn how she works, your in for some serious trouble :(

Wacharapong Chiowanich · July 16th, 2008, 09:12 PM

Thanks, Stephen. Your explanation is truly appreciated as I've heard from quite a few people about the difficulties in using autofocus on the Z7 compared to mostly trouble-free experience on the FX-1/Z1. A lot of what I've heard, though, is somewhat subjective. It could be just the less familiarity with the new camera or there could be some real performance issues with the Z7's focus.

Best
Wacharapong

Robert Bec · July 24th, 2008, 03:44 PM

Stephen what about the rolling shutter problem what is your work around that

cheers

Robert

Stephen Gradin · July 24th, 2008, 06:36 PM

I must admit, I don't like the effect that the rolling shutter displays during receptions, when there are multiple still camera flashes, but it goes by so fast it is usually not that bad. Most clients won't notice it. When it is really noticeable (like multiple flashes from multiple still cameras all at the same time), I'll cut to the other camera or I may add a few frames of a white matte (and quickly have the opacity fall off), to mimic a flash. This method hides the really obnoxious flashes that can cause pixelation of the HDV codec. Matrox RT.Xt also has a nice filter that mimics a camera flash that works really well in this instance.

Other than that, I have no other solution at this time. I must say, the Sony Z7U is much better in low light than practically every other camera in its class, so, that alone makes it ideal for low light HDV shooting. With this in mind, I can live with the rolling shutter.

Robert Bec · July 24th, 2008, 08:26 PM

Most of my weddings are a single camera shoot so it would be very hard for me to hide camera flashes so i guess i wait for something new or i purchase a Z1 which i think does a great job.

what are your thoughts

Robert

Bruce G. Cleveland · July 24th, 2008, 08:51 PM

Quote:

Originally Posted by Robert Bec

Most of my weddings are a single camera shoot so it would be very hard for me to hide camera flashes so i guess i wait for something new or i purchase a Z1 which i think does a great job.

what are your thoughts

Robert

Keep waiting Robert all the upcoming cameras are going to be using cmos sensors.

Bruce

Uli Mors · July 28th, 2008, 11:30 AM

what headlight do you use?

ULI

Robert Bec · August 3rd, 2008, 05:58 PM

Quote:

Originally Posted by Bruce G. Cleveland

Keep waiting Robert all the upcoming cameras are going to be using cmos sensors.

Bruce

Bruce

I am hiring a Z7 in the next few weeks over the weekend and i will finally know if this camera is for me. Reading all the positives from the guys who actually own a Z7 is giving me a good feeling.
I have done to much criticizing when i dont even own one so now i am going to hire it and take it through it's paces over 3 days.
I really hope it works out

Regards

Rob

Bruce G. Cleveland · August 3rd, 2008, 07:48 PM

Quote:

Originally Posted by Robert Bec

Bruce

I am hiring a Z7 in the next few weeks over the weekend and i will finally know if this camera is for me. Reading all the positives from the guys who actually own a Z7 is giving me a good feeling.
I have done to much criticizing when i dont even own one so now i am going to hire it and take it through it's paces over 3 days.
I really hope it works out

Regards

Rob

Good to hear Rob, keep us posted.

Bruce

Mike Wade · August 5th, 2008, 06:39 AM

Stephen, you mentioned that Matrox RT.X2 has a filter that mimics a camera flash. I can't seem to find it - could you pont me in the right direction, please ?

Stephen Gradin · August 7th, 2008, 10:48 AM

Mike Wade,

The filter is in the Preset section under Blur/Soft Focus. It's called Blow Out. You can also create a Blow In if you want (that's what I did), buy reversing the Key Frames and saving the effect as your own preset. I take the clip where I want to put the flash frame, and cut it at that spot so it's about 30 frames. Then I use either the Blow Out or my own Blow In. I sometimes use Blow Out or Blow In effects to make a quick transition from one shot to the next.

You can also create a white matte and drag it over top of your clip. Keep it about 7-10 frames and do a 100% (start)to 0% (end) opacity.

You may want to experiment with to see which works best for your particular shot. Good luck.

Stephen

Scott Hayes · August 11th, 2008, 09:12 AM

not all the upcoming cameras will be. you may want to think about going to Panasonic.

Tom Hardwick · August 11th, 2008, 10:01 AM

The rolling shutter effect really makes me wince, but I guess Stephen's right - most client's won't notice it.

CCD cameras such as the Z1 simply record electronic flashes as an overall brightening of the entire frame and if you happen to be shooting the shooter (which I often do to show the paparazzi attention the couple are getting as they sign the register, cut the cake, dance together) then the individual frames look just as you'd expect them to look, with the camera's flashgun forming the centre of a bright splodge.

Not so the CMOS chipped cameras. Electronic flash combined with the rolling shutter causes some very odd exposures, where unpredictably the top half or bottom third or top third of the frame is over-exposed. The same effect is visible if you're shooting a scene lit by flashes - ie you're not shooting into the lights but shooting the subjects themselves.

I'd love a Z7 for its low light capabilities, but for now the Z1 is giving the clients excellent value for money.

tom.

July 16th, 2008, 02:00 PM	#1
Stephen Gradin Contributor Join Date: Oct 2007 Location: Nottingham, MD Posts: 66	Focus and Low Light Tips 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. 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. 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.

July 16th, 2008, 05:12 PM	#2
Chad Dyle Major Player Join Date: Jun 2007 Location: New Orleans, LA Posts: 410	Stephen, That was a great explantion of the Z7 for wedding videographers. I moved to the Z7 from an FX-1 and was really nervous about using the camera. After a few weddings and long nights of playing with the camera, I began to learn how it works and just adjusted my shooting style to meet its needs. Its kind of like a new girlfriend, if you don't learn how she works, your in for some serious trouble :( __________________ www.chaddyle.com www.chaddyleproductions.com

July 24th, 2008, 06:36 PM	#5
Stephen Gradin Contributor Join Date: Oct 2007 Location: Nottingham, MD Posts: 66	I must admit, I don't like the effect that the rolling shutter displays during receptions, when there are multiple still camera flashes, but it goes by so fast it is usually not that bad. Most clients won't notice it. When it is really noticeable (like multiple flashes from multiple still cameras all at the same time), I'll cut to the other camera or I may add a few frames of a white matte (and quickly have the opacity fall off), to mimic a flash. This method hides the really obnoxious flashes that can cause pixelation of the HDV codec. Matrox RT.Xt also has a nice filter that mimics a camera flash that works really well in this instance. Other than that, I have no other solution at this time. I must say, the Sony Z7U is much better in low light than practically every other camera in its class, so, that alone makes it ideal for low light HDV shooting. With this in mind, I can live with the rolling shutter. __________________ Stephen Gradin Dockside Video Productions

August 7th, 2008, 10:48 AM	#12
Stephen Gradin Contributor Join Date: Oct 2007 Location: Nottingham, MD Posts: 66	Mike Wade, The filter is in the Preset section under Blur/Soft Focus. It's called Blow Out. You can also create a Blow In if you want (that's what I did), buy reversing the Key Frames and saving the effect as your own preset. I take the clip where I want to put the flash frame, and cut it at that spot so it's about 30 frames. Then I use either the Blow Out or my own Blow In. I sometimes use Blow Out or Blow In effects to make a quick transition from one shot to the next. You can also create a white matte and drag it over top of your clip. Keep it about 7-10 frames and do a 100% (start)to 0% (end) opacity. You may want to experiment with to see which works best for your particular shot. Good luck. Stephen __________________ Stephen Gradin Dockside Video Productions

August 11th, 2008, 09:12 AM	#13
Scott Hayes Major Player Join Date: Sep 2003 Location: Lexington, KY Posts: 692	cameras using CMOS not all the upcoming cameras will be. you may want to think about going to Panasonic.

July 16th, 2008, 09:12 PM	#3
Wacharapong Chiowanich Major Player Join Date: May 2008 Location: Bangkok, Thailand Posts: 400	Thanks, Stephen. Your explanation is truly appreciated as I've heard from quite a few people about the difficulties in using autofocus on the Z7 compared to mostly trouble-free experience on the FX-1/Z1. A lot of what I've heard, though, is somewhat subjective. It could be just the less familiarity with the new camera or there could be some real performance issues with the Z7's focus. Best Wacharapong

July 24th, 2008, 03:44 PM	#4
Robert Bec Major Player Join Date: Aug 2007 Location: Sydney Australia Posts: 358	Stephen what about the rolling shutter problem what is your work around that cheers Robert

July 24th, 2008, 08:26 PM	#6
Robert Bec Major Player Join Date: Aug 2007 Location: Sydney Australia Posts: 358	Most of my weddings are a single camera shoot so it would be very hard for me to hide camera flashes so i guess i wait for something new or i purchase a Z1 which i think does a great job. what are your thoughts Robert

July 28th, 2008, 11:30 AM	#8
Uli Mors Major Player Join Date: May 2006 Location: Germany Posts: 565	what headlight do you use? ULI

August 5th, 2008, 06:39 AM	#11
Mike Wade Regular Crew Join Date: Feb 2005 Location: Holmfirth, West Yorkshire, UK Posts: 161	Stephen, you mentioned that Matrox RT.X2 has a filter that mimics a camera flash. I can't seem to find it - could you pont me in the right direction, please ?

August 11th, 2008, 10:01 AM	#14
Tom Hardwick Inner Circle Join Date: Mar 2003 Location: Billericay, England UK Posts: 4,711	The rolling shutter effect really makes me wince, but I guess Stephen's right - most client's won't notice it. CCD cameras such as the Z1 simply record electronic flashes as an overall brightening of the entire frame and if you happen to be shooting the shooter (which I often do to show the paparazzi attention the couple are getting as they sign the register, cut the cake, dance together) then the individual frames look just as you'd expect them to look, with the camera's flashgun forming the centre of a bright splodge. Not so the CMOS chipped cameras. Electronic flash combined with the rolling shutter causes some very odd exposures, where unpredictably the top half or bottom third or top third of the frame is over-exposed. The same effect is visible if you're shooting a scene lit by flashes - ie you're not shooting into the lights but shooting the subjects themselves. I'd love a Z7 for its low light capabilities, but for now the Z1 is giving the clients excellent value for money. tom.