RED One: wobble effect with long lenses

[Alberto Saiz]

HI!

I'm a wildlife cameraman and im currently working in two projects with RED One camera. we use Nikon lenses (80-200, 300 and 500mm) and shoot in 4K,3K and 2K when high speed is needed. When we`re working with long lenses we´re facing a problem of wooble effect in the image.it starts when the heat of the atmosphere goes up, but i think that 18ºC and 10.00 AM its not so hot! First of all we think that it would be heat shimmer, but we didnt have had this issue so strong working with Super 16mm film cameras in the past and in midday hours, so I think it has to be because the rolling shutter and the CMOS of the RED camera, but I was shooting on a sturdy tripod with no wind...What do you think?

If RED is so sensitive to the heat shimmer, its going to be a problem for us to work in a lot of circumstances and distances to the subject. On the other hand the camera is great but we´re surprised and worried about this wooble...

I know that some of you have worked with this camera in wild conditions in africa, alaska, finland...etc. Did you have this problem? any solutions?

Thank you very much in advance!

A.Saiz

[Steve Phillipps]

Heat shimmer I would say would only be an optical effect and it should not make any difference what camera/sensor you have, just the lens magnification you have.

If you're just comparing it to Super 16 that may be the problem as video images are much more steady and also sharper looking so that any movement tends to show up more. Film has a gentle movement of its own introduced by the moving mechanisms. This is why we need to be using bigger tripods for HD than we did with Super 16, together with the fact that we're viewing on bigger screens.

I'd be surprised if the RED had any more problem with this than any other video camera - but I'm not speaking from first hand experience.

Good luck.

Steve

[Ofer Levy]

I agree with Steve and also think it has nothing to do with the camera. I notice the same issue when using my Sony PMW EX3 later in the day when it becomes warmer.
Cheers,
Ofer

[Lauri Kettunen]

Yes, this issue is not about the camera. Instead, this has to do with temperature differences which imply the electromagnetic/optical properties of air are not homogeneous, but instead the properties change between the camera and the object. As a result light rays bend. Typically this appears in the spring time or on hot summer days when the sun shines and warms locally say some dark spot --such as a paved road-- or if there's a cold spot between, say such as a frozen lake or lake with cold water. Once wittnessed that a pine appeared like rubber when it wobbled in the screen. Have coupled times noticed that my car radio has lost proper signal under similar conditions. Obviously, when shooting the effect is the stronger the longer lens one uses.

Hope this helps.

[Tony Davies-Patrick]

Yes, I'd definitely agree with the notion that heat-generated air waves are the culprit.

This is especially true when using 300-1000mm lenses. The stronger the magnification the bigger the problem becomes. For example when filming the same subject using a 300mm and 600mm Nikkor on a Canon XL body, the 600mm footage will generally have less contrast and more obvious flowing air 'wave' patterns (it should be noted that all XL camcorders multiply by a factor of 7-8 when using Nikkors, so produce far more pronounced problems with 'shimmering' than when using the Red).

The obvious solution is to either get closer to the subject and use a less-extreme telephoto lens, or simply to film during early morning before the sun has too much affect on the low laying blankets of air.

Another option is to film at higher altitude and to avoid low level areas during warm weather.

But sometimes there is no other option than to use the longest super-telephoto lens during the warmest part of a summer day just to obtain that once-in-a-lifetime section of footage.
In this scenario I've often found that by tweaking the video edited footage in-post by lowering brightness slightly and upping both colour and contrast it can help tone down the 'wave' problem enough to save some clips.

[Steve Phillipps]

I think it's obvious that Alberto is aware that it's the heat shimmer that's responsible, it's just that he's noticing it much more on the RED than the Super 16 cameras he's used to. That's what the query really referred to.
Steve

[Tony Davies-Patrick]

It all depends on the magnifications and the actual lenses used during those conditions as almost all video cameras SD or HD would show very similar results, including the Red. The 16mm or 35mm film footage would still show the same results with 'shimmer', although as Steve indicated, it would produce a less enhanced 'look' due to the difference between moving film emulsion and the CMOS of the Red.

However, if these conditions are ONLY enhanced when using the Red (when compared to other digital video cameras) I'd be very interested to know why and what causes it.

[Alberto Saiz]

Thank you all for the quick answers. As Steve says we also think it has to be a heat issue and also I noticed it working with other HD cameras, like the JVC HD200 and its 7x magnification. What surprised us is the high sensitivity of RED in this situations, so I was wondering how many of you suffer this problem working with RED and telephotos lenses, and what solutions do you think could minimize this effect. Any experiences are welcome as we're facing a challenge shooting in a lot of situations if this issue is so common. I will tell you if i find something. Thanks a lot!

[Chris Hurd]

The longer the lens focal length and the higher the resolution, the more pronounced this effect is, and it can occur even at seemingly mild temperatures. The only relevance as far as RED is concerned is the high resolution of its image, which makes the shimmering effect that much more apparent.

[Dale Guthormsen]

Good evening,

I agree with most everything said her.

However!!! It really is not as much heat as it is intense just light waves!! I get this shooting in all types of cold temperatures with light refracting off of snow as an example. certainly in mild weather heat does seem to be the culprit, but i see it in as cold as -20 degrees on a sunny morning. Also just using the standard 20x lens zoomed in is enough to enhance the problem!!! with my larger lenses it is even more pronounced.


If anyone has a suggestion that will work, other than overcast day filming only, I am all ears and would love to hear it!!!!

[Lauri Kettunen]

Originally Posted by Dale Guthormsen

but i see it in as cold as -20 degrees on a sunny morning.

Yes, same here, and that's the point. It's not the absolute temperature value, but instead the variation of temperature (and the region of warmer air moving upwards) between the lens and the target.

I haven't noticed any special effect with Red One. But, as Chris says higher resolution and perhaps also shorter depth of focus attract the eye more easily.

[Kent Frost]

A perfect example of seeing this through nothing but optics and your own eye... put the strongest eyepiece you have on a telescope and aim it at a the furthest street sign you can see. With the right equipment, you might be able to get a sign half a mile away from you seem as if it were only about 20 feet away, maybe less. But when you magnify to that intensity, the light that is available that comes from that object from that distance is going to come across some obstacles, as well as be much more dispersed from its point of origin than it would be if you were actually standing 20 feet away from it.

[Bryce Comer]

Hi Alberto,
Are you seeing any difference on the long shots you are talking about when you make a pan? I have heard that long shots can be effected by the skew issue with the cmos sensors when panning. Not sure if this is relevant, but i am certainly curious to know if it is an issue.
Thanks,
Bryce

[Chris Soucy]

Originally Posted by Alberto Saiz

shooting on a sturdy tripod with no wind...

Guess what's holding that very high definition camera and it's humungous lens to that sturdy tripod?

At best, 2 X 3/8" S & W, in - line screws. At worst? 1 X 1/4" S & W screw.

The chance that either of these fixings will prevent the camera wobbling back and forth with the slightest provocation is about 3 zillion to 1.

At that resolution and those lens lengths, it doesn't take much.

Much as I believe the majority of what you're seeing is simple diffraction due to air temperature differentials, I wouldn't rule out the tripod fixing as a possible culprit for part of it.

If physically strapping the camera down to the head plate doesn't make any difference, I'll be suprised, as I get this wobble with my Canon XH A1 all the time @ 20X zoom (when it isn't strapped), and it sure as hell ain't diffraction (well, it wouldn't be when the air speed is approaching 30 knots).


CS

[Steve Phillipps]

Originally Posted by Chris Soucy

Guess what's holding that very high definition camera and it's humungous lens to that sturdy tripod?

At best, 2 X 3/8" S & W, in - line screws. At worst? 1 X 1/4" S & W screw.

The chance that either of these fixings will prevent the camera wobbling back and forth with the slightest provocation is about 3 zillion to 1.

At that resolution and those lens lengths, it doesn't take much.

Much as I believe the majority of what you're seeing is simple diffraction due to air temperature differentials, I wouldn't rule out the tripod fixing as a possible culprit for part of it.

If physically strapping the camera down to the head plate doesn't make any difference, I'll be suprised, as I get this wobble with my Canon XH A1 all the time @ 20X zoom (when it isn't strapped), and it sure as hell ain't diffraction (well, it wouldn't be when the air speed is approaching 30 knots).


CS

Shouldn't be a problem with a decent tripod though. If you use a crappy little Manfrotto or similar then yes, but get into the realms of serious kit like O'Connor 2060 or 2575, Ronford Baker Atlas 30 or the heavy Sachtlers and it should be rock steady, even when panning and tilting.
Steve