Proper exposure workflow

Chris Johnston

Chris Johnston

Veteran
I've got a 25K budget approved for 1 Oct. Looking to get a couple more cameras for (primarily) studio work.

Also wanted one of these cams to be either a af100 or fs100 (leaning to fs100)

My question is about controlling exposure if I take it outside (florida, sunny)
This cam is apparently very sensitive so I'm wondering how to get exposure right. I've seen numerous clips where they apparently
have to turn the shutter speed way up......

If I want to shoot something at a 60 shutter speed and a wide open iris (1.4- 2.8 ish) outside is my only option something like a
Heliopan variable ND filter? Is that how everyone is controlling exposure since there's no negitive gain?
and would that particular variable ND darken it up enough to shoot something with those settings?

It doesn't seem like a bad workflow...set shutter to 60, set the iris to the setting I want, should I chose to want a shallow DOF. and then just adjust the vari ND to get the exposure right.
Hate to pop out the newbie question but I just see sooooo many posts about this, just want to make sure this is the correct/easiest way to do it.....
 
That is EXACTLY how I do it. Shutter speed set to twice frame rate (48 for 24p 60 for 30P or 60i). Set iris to what I want. Use Heliopan to dial in correct exposure. Works just
great.
 
Thanks AK will the heliopan darken enough to get a wide open iris? or do I have to add aditional nd? (if it's bright outside)
 
videohog said:
Thanks AK will the heliopan darken enough to get a wide open iris? or do I have to add aditional nd? (if it's bright outside)
Click to expand...

Well, I can't say for absolute certain as I just have the kit lens right now. I am waiting for the new Sony adaptor (rumored announcement on
August 24th) to drop before I purchase my additional lenses, just want to see what that is all about as it may change what lenses I buy.
So, my kit lens only opens to F3.5. However, when I am outside on a sunny day, at F3.5, I still have an additional 1.5 - 2 stops on the Heliopan
filter, so I think that F2.8 at least would work fine. The Heliopan is supposed to give you up to 6.6 stops of ND. If you are interested in seeing how
it performs (sharpness, color and so on) you can take a look at this link:

http://exposureroom.com/members/alaskacameradude/14d879d0c3924609974edd0388478689/
 
jetswing said:
6 stops isn't going to be enough for Florida midday sun -- especially at wide open.
Click to expand...

How would you get around that? OK to screw another (say...hard 2 or 3 stop) nd filter onto the heliopan?
I'd hate to not have DOF if I want it, just because it's sunny.
 
The Heliopan gives you almost 7 stops. I'm not in Florida, so I don't know, but I think you would be OK at F 2.8. At F1.4 you are probably going to need more ND.
However, the Heliopan does NOT have front threads, so you can NOT add another filter to it! You might look at the new Tiffen variable ND which was introduced at
NAB. It is supposed to give you from 2-8 stops instead of 1-6.6 which is what the Heliopan does. However, both of these filters are hard to find and seem to be
out of stock quite a bit, so you will probably have to look around a bit.
 
Anyone ever use the tiffen? I've read a few posts about about variable nd's getting soft on longer glass. (although a 85mm nikon is the longest glass I have)
 
alaskacameradude said:
The Heliopan gives you almost 7 stops. I'm not in Florida, so I don't know, but I think you would be OK at F 2.8. At F1.4 you are probably going to need more ND.
However, the Heliopan does NOT have front threads, so you can NOT add another filter to it! You might look at the new Tiffen variable ND which was introduced at
NAB. It is supposed to give you from 2-8 stops instead of 1-6.6 which is what the Heliopan does. However, both of these filters are hard to find and seem to be
out of stock quite a bit, so you will probably have to look around a bit.
Click to expand...

I shot up on a glacier a few times this summer, and when I threw my ND1.2 (4 stops) in front of the lens I could stop down pretty far. At 3.5, 1/120 was fine... and thats on a glacier which is probably a stop or two brighter than Florida. I was able to shoot at 1/60 with that same ND perfectly fine last weekend in southern california mid day... at 3.5. 6.6 stops is probably safe.
I also threw on my 50 1.4, but it was raining, so thats not a fair comparison. My 80-200 f4 also worked fine obviously.

Both my 80-200 f4 and 50 1.4 were not wide open though. I was at f2 on my 50 and 5.6 on my 80-200. I like to stop down each of my lenses a slight bit when I use them to get them at their sharpest.

Keep in mind if you have never used this camera that you most likely do not need 1.4. I found F2 at 50 to be extremely shallow. Hell ive even gotten lots of shallow stuff with this camera at 5.6 below 100mm.

With all of that said though, if Tiffen does have the 2-8 stop ND, then I would say go with that to be safe. I have a Tiffen ND1.2 for my matte box and love it. Tiffen makes some quality filters, so I would not hesitate to go with them but I have not used that specific one.

Be excited for this camera! You will definitely love it! Just be prepared to want to immediately pick it up to go shoot something again once you sit down at the desk and see some of what it creates.
 
Yeah, I have always been just fine with the Heliopan, but the kit lens only goes to f3.5. I was just guessing that since I still had a couple stops available, that it would be
ok for F2.8. However, as you said, you can get stuff that is way shallow, even with the slow kit lens.....well shallow compared to a video camera anyways. If you used a F1.4 on
it, you'd probably only be able to keep one side of someone's face in focus!

I would echo the comments about how you will just want to go shoot with this thing. It just gives you such beautiful looking stuff, it's kind of amazing to be honest.
I'm shooting some stuff for Toyota on the 8th, and this is the first time, I feel like I have a camera that can do justice to bigger budget TV spots.
 
Try traditional ND, they have less issues. NDfaders can cause some odd image quirks.

For out door work in broad daylight, you need 3x .9 ND filters to shoot at a T2:8 @ ISO800
 
I don't see what camera DOSmedia was using but a HDSLR ISO goes down to 100, but this camera at 0db is around 800 as TimurCivan mention above.
That is 3 more f stops.
 
TimurCivan said:
Try traditional ND, they have less issues. NDfaders can cause some odd image quirks.

For out door work in broad daylight, you need 3x .9 ND filters to shoot at a T2:8 @ ISO800
Click to expand...

Not trying to start anything as you obviously know your stuff, but just wondering if you've used a Heliopan variable ND before?
All variable ND's are NOT equal, (that's why some cost $80-$125 and the Heliopan costs $400 plus) and the Heliopan is awfully close
to a flat ND filter in my opinion. Of course, that's just my opinion, although I do know that Philip Bloom has also said this on his
blog. However, I'm not saying I'm right, you may well have seen issues with this filter that I haven't, I don't think I tend
to work on as high end stuff as you do, so if you have used it and seen issues, I'd defer to your experience.
 
To shoot at 0db af F2.0 in bright daylight, I had to throw 9 stops of ND up there in the Matte Box. (a 1.8 and a .9 stacked - 6+3 stops). YMMV of course
 
Thanks for all the info. It looks like the heliopan or tiffen are something I think are (almost) required to shoot with this cam. (at least for me at the beach)
I'm still a little confused about the iso/gain relationship. Is there a chart that lists the X gain = X ISO numbers anywhere?


EDIT: I plan on getting the kit glass also but have several older nikons. I don't suppose the birger mount will be available for this cam by Oct 1 which is
a bummer because I have some nice Canon glass that I wanted to use. (which was one of the main reasons the AF100 was still being considered)
 
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Iso is the "actual" light sensitivity. ISO800 on a fs100 and a AF100 and 5D should be the same.

Gain is the video term for how much the camera boosts the signal from that starting ISO point. Its measured in dB. Every 6 dB is a stop worth of light.
 
Gotcha. ISO is always 800, Gain allows you to "simulate" moving the ISO higher but since there's no negative gain, 800 is as far as you can go. (lower)
 
This is from Abel Cine and was specifically done for the F3, but the numbers should be similar for the FS100 which uses the same sensor (the gain / ISO information is in a chart from on the Abel Cine page):

http://blog.abelcine.com/2011/03/11/abelcine-tests-the-sony-f3-iso-rating/

"We’ve done a lot of testing with the Sony PMW-F3 camera and had great results. Our tests included sensitivity, dynamic range and low light performance. In a three part series, Mitch and I will cover all of these topics with the hopes of shedding light on what this camera can do. The F3 had the following settings for this test: 1920×1080 23.98p, Rec709 Gamma (STD5), Auto Knee OFF, Black Gamma 0, Matrix Standard, Detail OFF, Aperture OFF. All testing was performed with a Leader LV7330 scope, DSC Labs Camalign ChromaDuMonde chart, and Sekonic L-758Cine light meter. Watch the video above to see how we determined the ISO ratings of the camera at different gain levels, or keep reading below to see our results."

"Here are our results:

Gain db Level / ISO Rating

-3 db 500 ISO (FS100 doesn't have this option)

0 db 800 ISO

+3 db 1000 ISO

+6 db1600 ISO

+9 db 2000 ISO

+12 db 3200 ISO

+18 db 6400 ISO
 
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Douglas Villalba said:
I don't see what camera DOSmedia was using but a HDSLR ISO goes down to 100, but this camera at 0db is around 800 as TimurCivan mention above.
That is 3 more f stops.
Click to expand...

yeah I know what an HDSLR does.

Obviously since I am posting in this forum and thread, I use a FS100, so I dont get what you are trying to say.
 
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