Blackmagic Forum

Hi,

I sometimes film live concerts, such as dance recitals and one of my cameras is a Pocket 6k Pro paired with a telephoto lens (usually the 100-400mm or the 55-250 EFS lens) on a tripod. This is used to grab a variety of close-ups that will be cut in with the footage from the other cameras. Would you recommend leaving the image stabilization on the lens on or off?

Any advice greatly appreciated.

Thanks,
Matthew

Since your camera supports gyro stabilization with DR, you might do better by keeping it off.
The IS on long lenses is rather optimized for photography and can tend to ‘stick’ when panning.

Uli Plank wrote:Since your camera supports gyro stabilization with DR, you might do better by keeping it off.
The IS on long lenses is rather optimized for photography and can tend to ‘stick’ when panning.

Great, thanks for the tip.

The Canon 100-400 does have 2 different OIS modes, one is for panning, the other mode is kind of "sticky". I used that lens with the UM46k for a Fußball doc to film a game and it worked very well.

Make sure to have rods and a lens support system to make your setup as rigid as possible, otherwise you get vibrations introduced. A heavy tripod with a smooth head will also help.

You might want to set your shutter to 90° to get less motion blur for later in post stabilization - if the light situation is ok with this.

FYI so this does not surprise you when it happens:
When the lens OIS is switched on and you got the framing locked - you will find that through the OIS the framing is starting to wander around a bit. That's just the way it works.

Robert Niessner wrote:The Canon 100-400 does have 2 different OIS modes, one is for panning, the other mode is kind of "sticky". I used that lens with the UM46k for a Fußball doc to film a game and it worked very well.

Make sure to have rods and a lens support system to make your setup as rigid as possible, otherwise you get vibrations introduced. A heavy tripod with a smooth head will also help.

You might want to set your shutter to 90° to get less motion blur for later in post stabilization - if the light situation is ok with this.

FYI so this does not surprise you when it happens:
When the lens OIS is switched on and you got the framing locked - you will find that through the OIS the framing is starting to wander around a bit. That's just the way it works.

Great, thanks for the tips Robert.

FYI. As a general rule, it is best to turn image stabilization off, if the camera is on sticks. Worked for me.

Art Roberts wrote:FYI. As a general rule, it is best to turn image stabilization off, if the camera is on sticks. Worked for me.

Ok, thanks

Depends on the quality of those sticks, in particular with a long lens.

Here is an example shot I made with the Canon 100-400mm with active OIS on my UM46k and a Sachtler tripod from said Fußball game:
https://laufbildkommission.filemail.com ... dtxqpvkpjy

As you can see it works very well with the active OIS.

Robert Niessner wrote:Here is an example shot I made with the Canon 100-400mm with active OIS on my UM46k and a Sachtler tripod from said Fußball game:
https://laufbildkommission.filemail.com ... dtxqpvkpjy

As you can see it works very well with the active OIS.

That looks great, thanks Robert.

Thanks to everyone who has replied so far on this thread. I just thought I’d post a quick update.

I’ve found it works best to leave the image stabilisation on. This is because I’m never really locked off as I’m following the action around stage so the IS helps to minimise any shake from my hands. With the 100-400 I use the option that allows panning.

Generally when it’s at a proper theatre and the lighting is good, it works well and the shots from the longer lenses cut in nicely with the rest of it, like in the clips below:


However, I recently ran into an issue when shooting a concert in a sports gym. Firstly, the lighting was very dark which isn’t great with those long lenses that aren’t very fast. Also, because I was on the same floor as the drum, the vibration gave me some nasty shake artefacts. It’s only noticeable when using the longer lenses and only where the drum kicks in. It was noticeable to me even on the camera LCD screen so I tried turning image stabilisation off but this didn’t make any difference.

As you can see from the clip below it’s quite noticeable when viewed on a big screen or when you're close to the screen. Anything I can do to rescue it in Resolve? Image Stabilisation isn't helping.
https://vimeo.com/819223459/1854b72cdc

Also, what’s the best way to stop this from happening going forward? I’m assuming a more heavy duty tripod, any suggestions? Currently, I use the E-Image GH06F Fluid Head and E-Image 761 AT Legs and I like this because the head is quite smooth and it’s good in tight spaces. Often I’m not given much room to work with and have to go over seats etc... (see screenshot attached). Sometimes I even have to overlap the legs on the two tripods.

Any suggestions for tripods or lens support systems greatly appreciated.

Thanks,

Matthew

If you have deep pockets and have access via a rental, try something like the OConnor 1040 or even the top of the line 2945 head with a heavy tripod.

But I would first try laying down a few layers of the best yoga mats on the floor that is vibrating. That might be a practical approach that absorbs the vibrations.

rick.lang wrote:If you have deep pockets and have access via a rental, try something like the OConnor 1040 or even the top of the line 2945 head with a heavy tripod.

But I would first try laying down a few layers of the best yoga mats on the floor that is vibrating. That might be a practical approach that absorbs the vibrations.

Thanks Rick. I'd not thought of laying something on the floor, I'll give that a try. Unfortunately my pockets aren't deep enough for an OConnor.

Misery loves company so you know you’re well loved!

Matthew_Lawrence wrote:As you can see from the clip below it’s quite noticeable when viewed on a big screen or when you're close to the screen. Anything I can do to rescue it in Resolve? Image Stabilisation isn't helping.
https://vimeo.com/819223459/1854b72cdc

While this is certainly annoying for you as the cinematographer I can assure you that your audience won't notice or when noticing will still accept it as part of the performance. Because of the vibrations the image will move a bit very fast, resulting in motion blur. When you do post stabilization it will lock the camera movement but amplify the visibility of the motion blur effect much more. That's the trade off.

Matthew_Lawrence wrote:Also, what’s the best way to stop this from happening going forward? I’m assuming a more heavy duty tripod, any suggestions? Currently, I use the E-Image GH06F Fluid Head and E-Image 761 AT Legs and I like this because the head is quite smooth and it’s good in tight spaces. Often I’m not given much room to work with and have to go over seats etc... (see screenshot attached). Sometimes I even have to overlap the legs on the two tripods.

Adding mass will improve resistance to vibrations. Also uncoupling your tripod from the vibrating ground.
I wouldn't use a yoga mat as those tend to make things wobbly.
There are anti-vibration mats for loudspeakers for example. You will need to weight your system and then buy a mat for that weight range.

From your picture I also saw a flaw in your rig. Because of the battery grip your camera sits a few centimeters higher, leading to amplification of vibrations hitting your system. And there seems to be now extra lens support keeping your long lens from "swinging".

Rig up your camera with a cage, keep the optical center as low as possible to the tripod. Use rods and a lens support screwed into the lens foot. Make everything as rigid as possible.

For a tripod - I always would go for a 100mm bowl over a 75mm bowl - because of better rigidity.

Great, thanks Robert. I'll look into a cage. I think I didn't consider it before as it makes the camera a bit heavier for gimbal work.

I take your point about the centre of gravity. On the photo I think I was using the 18-135 STM which isn't too bad. With the 100-400 I tend to mount the lens to the tripod like people do with a DSLR.

Thanks

Hi,

Just following up on this issue. I think it’s a fault with the lens. Today I used it again for the first time in a while and I had the same issue. This time I was at the wider end (around 55mm) rather than the telephoto end:
https://vimeo.com/847654382/92d37cc51f?share=copy

I tried turning the image stabilisation off but this didn’t help either.

Again it seems to be caused by the vibration of the music but the vibration really wasn’t that strong and I had two other cameras with different lenses that didn’t have the issue. In fact, one of them was zoomed all the way to 400mm and it was still fine.

I've tested the lens at home on various different cameras and can't seem to re-create the issue. It happens when I'm shooting a show with loud music, particularly drums or a beat.


Has anyone encountered this issue before? The lens didn’t use to do this. It first started doing it a few months ago. The previous time it happened, I was at the telephoto end and I thought it was the vibration from the drums:
https://vimeo.com/819223459/1854b72cdc

Any help or suggestions appreciated.

Thanks,

Matthew

I didn’t spot it at first, looking at the close-up sample movie. When I bump my ursa mini and I use a 300 mm the shake looks completely different. Everything moves.
Your camera has a relative slow read out speed so te whole image should move. That’s not happening. So I don’t think it’s a camera shake.

It looks like your lens is hunting for focus. The girl get’s in and out of it, just before the “shake” appears.
The kids start to move when the beat kicks in so in that sense it might be related to the beat. If I were you I would check what happens when auto focus is turned off.

At the moment there are a couple of post about updated software that didn’t work out to well between camera and lens. Maybe that’s causing you issues as well. In that case down grade to the version that worked for lens and camera.

Bunk Timmer wrote:It looks like your lens is hunting for focus. The girl get’s in and out of it, just before the “shake” appears.
The kids start to move when the beat kicks in so in that sense it might be related to the beat. If I were you I

Thanks for the suggestions. In this case the auto focus and image stabilisation were both off. To be honest I tried the stabilisation both on and off but it didn't make any difference in terms of this issue.

I think it is a fault with the way the lens is communicating to the camera as I don't have this issue with my other lenses. I haven't updated the firmware for either the camera or the lens and it used to work fine. I don't think I'll risk using this lens on future jobs.

Thanks to everyone who got back to me on this thread.

Just happened to see this thread by chance. It is not unknown for the focus motor in the Canon 18-135 STM lens to come loose and cause focus issues. There are a few videos on YT showing this being fixed.
I also use this lens, but so far all is well.