Filter for IR contamination

[Dave Morrison]

Derek, do you know if this occurs with the compact fluoro's like I'd put into my RifaLight?

[Brian Cassar]

Dave......yes I did mean fluorescent.

Derek....LED's do not produce such effect. In fact I swapped my old trusted PAG halogen on-board lamp with a LED Zylight 90 and the change was dramatic (without the 486). In fact once I was caught out with my 486 in the bag and I was filming under tungsten light. In order to save the day I just switched on the Zylight, increased the intensity and the blacks turned to blacks again (since I had no time to search and attach the 486).

What I did find strange lately was that a black suit turned bluish (even with the 486 attached to the EX3) when filming under low energy saver lamps. I was filming in a hall lit up only with these PL lights (they were of the cold light type) and this particular person ended up with a bluish suit. It was only a one off thing but I found it very strange considering that I had the 486 on. Other blacks remained black.

[Dave Morrison]

Brian, thanks for that. I was wondering if the CRI of compact fluoro's would be better than the average office fluoro's in overhead fixtures OR if the compacts have the same, more or less IR output than the standard overhead tubes.

[Max Allen]

Originally Posted by Brian Cassar

Dave......yes I did mean fluorescent.

I swapped my old trusted PAG halogen on-board lamp with a LED Zylight 90

Greetings Brian.

For z90 how do you handle mounting and powering. I avoid the ex1 front accessory shoe because it's flimsy and can't handle the weight of anything but the lightest weight on-camera lights, much less the the z90.

For powering I tried the Bebob coco-EX using z50 but the battery drain was too rapid so no way to use it with z90 of course. I tried the tekkeon battery and carried it in a pocket but that is precarious and limits camera movement.

My next solution is v-mount on a zacuto with p-tap and rod arm for the z90. Do you have a picture of your rig?

[Brian Cassar]

Hi Max, I use the Z90 primarily on my EX3. The Z90 is surprisingly very light in weight and cannot see any problem in putting it on the EX1 front accessory shoe. I have the Bebob EX3 V-mount adaptor togeher with the VF Gadget shoulder mount. The Z90 draws up to 30 watts in full power and so you need a powerful battery to be able to sustain such power. I use a BlueShape 210 WHr battery and power both the camera and light. Apart from giving me many hours of filming, this battery also mkes the camera back heavy.

Going on to the EX1, I do have an EX1 as a spare camera in case the EX3 decides to pack in. I have bought another VF gadget plate and found that it can be used with the EX1 and will turn the camera from a hand held to a shoulder mounted camera. I have bought a Hawk Woods V-mount adaptor and has attached this to the Vf Gadget so that I can power both the EX1 and the Zylight with a V-mount battery (the same that I use for the EX3). I have never used the EX1 with the Z90 on board but as I said I cannot see any problem in this.

Please note that for stability purposes I have attached the Z90 to the accessory shoe with the help of an accessory that has a hot shoe end at one end and a screw that fits the Zylight at the other end. By this way the Zylight is closer to the camera body and hence more stable. I did not buy the articulated arm which would make the rig rather unstable. I use my EX3 mainly for shoulder mounted wedding filming (no tripods) and hence stability and compactness is of prime importance. The Pag light was surprisingly more protruding than the low profile Zylight!

[Piotr Wozniacki]

Brian,

I'm aware it's a bit OT in this thread, but you got me interested in your EX1 solution. Could you please elaborate on the parts used, and perhaps put some pics?

[Olof Ekbergh]

I don't Know why' but I don't seem to have a huge problem with Blacks in my studio.

I use a fairly inexpensive black felt backdrop stretched very tight over a wood frame.

Frame below is from a shoot yesterday. It is lit with a combination of florescent and tungsten lights, with careful control of spill onto BG.

It is shot with an EX3, there is absolutely no red tint in the blacks. White balance was with a pure white card, not a warm card.

I put the frame into PSD to check balance in blacks with eye dropper, from an export out of Color. No correction applied.

I know that if I spill tungsten light onto fabric I will get warm blacks.

So in my opinion if lit well there is no problem with red shift in blacks at least in my studio.

The shots below show frame, and light setup. There is also a softbox just to the right of the camera that shot photo.

[Alex Raskin]

Originally Posted by Bob Grant

As far as I know the problem only shows up with tungsten and sunlight. You shoud be quite safe with fluro, LED and HMI lighting.

I've seen the black -> brown effect under all lighting (except HMI, which I simply did not have access to - but probably will be the same story there.)

My understanding is, it depends on the fabric/light combination.

The only way to be safe is to use the darn 486 filter with your EX1/3.

[Dave Morrison]

Olof, if that doctor were wearing a black business suit, are you saying that the IR problem still wouldn't be there?

[Olof Ekbergh]

Here is a frame grab from FCP in PSD with info tool.

We shot him in suit as well.

Go figure I don't see any overly red. Maybe it is just my PP. I am using a UV filter but that is it.

[Ben Chiu]

Originally Posted by Olof Ekbergh

Here is a frame grab from FCP in PSD with info tool.

We shot him in suit as well.

Go figure I don't see any overly red. Maybe it is just my PP. I am using a UV filter but that is it.

It could be that the materials you're shooting don't have the problem. I've only noticed the problem mostly on synthetics and blends.

[Ryan Mitchell]

Originally Posted by Ben Chiu

It could be that the materials you're shooting don't have the problem. I've only noticed the problem mostly on synthetics and blends.

My understanding, not having seen it first-hand due to the fact that I've had the 486 filter on since day-one, is that it is related to the material of the black object in question, not the color black itself. Something about the way the material reflects the IR spectrum differently that the camera is sensitive to and ends up picking up and recording - it's over my head, but that's what I've read in this post and a couple of others.

[Eva Sturm]

Originally Posted by Ben Chiu

It could be that the materials you're shooting don't have the problem. I've only noticed the problem mostly on synthetics and blends.

Here's a variety of fabrics. The neutral colored pic (IMG_0039.jpg, right hand side) was shot with a CANON SLR, the other one with my EX1. It shows drastically, that certain fabrics reflect a huge amount of IR-light.

I always use a UV-filter, I do need another one.

Rgds, Eva

[Max Allen]

Originally Posted by Brian Cassar

Hi Max, I use the Z90 primarily on my EX3. The Z90 is surprisingly very light in weight and cannot see any problem in putting it on the EX1 front accessory shoe. I have the Bebob EX3 V-mount adaptor togeher with the VF Gadget shoulder mount. The Z90 draws up to 30 watts in full power and so you need a powerful battery to be able to sustain such power. I use a BlueShape 210 WHr battery and power both the camera and light. Apart from giving me many hours of filming, this battery also mkes the camera back heavy.

Going on to the EX1, I do have an EX1 as a spare camera in case the EX3 decides to pack in. I have bought another VF gadget plate and found that it can be used with the EX1 and will turn the camera from a hand held to a shoulder mounted camera. I have bought a Hawk Woods V-mount adaptor and has attached this to the Vf Gadget so that I can power both the EX1 and the Zylight with a V-mount battery (the same that I use for the EX3). I have never used the EX1 with the Z90 on board but as I said I cannot see any problem in this.

Please note that for stability purposes I have attached the Z90 to the accessory shoe with the help of an accessory that has a hot shoe end at one end and a screw that fits the Zylight at the other end. By this way the Zylight is closer to the camera body and hence more stable. I did not buy the articulated arm which would make the rig rather unstable. I use my EX3 mainly for shoulder mounted wedding filming (no tripods) and hence stability and compactness is of prime importance. The Pag light was surprisingly more protruding than the low profile Zylight!

True with no arm the rig will be more stable. We have a the mount that attaches the light to the shoe as you say, but I'm not tall so the nose shadow and possible slight underlighting a straight on angle causes is not a good path for me, aside from other shadows from mattebox, shotgun and lens attachments in a macro shot. The arm opens up angles for me. We have both the z50 and z90. I'm also interested to what your converted EX1 looks like!

[George Griswold]

GRAY SUIT TURNS BROWN. Major convention footage shown here ... mixed lighting with tungsten and 5600 sources. Daylight preset balance (also tried setting WB with same result) Luckily client speced the EX-3... what would I do if I pitched this camera and this happened?

I have shot for two days with no color shifts before this one. I am now wondering if certain fabrics react differently (cotton, wool, etc.). I was thinking that this problem was infrequent and overblown-- not any more. I will review all 20 pages of this thread, but I think if Sony does not offer a "patch" that class action litigation may be in order. In 25 years shooting broadcast video I have never seen anything this extreme. Yikes! The old Ikegami never looked like this. I guess I have 486 filter in my future.