5D Mark II Shutter Exposed! (Part II)

[Mark Hahn]

I did a really quick run with just one setting. I put on my 24-105 lens and set it to c3 (my standard video setup). I noted that as I changed the focal length the speed reading would change to match, verifying what people have said.

I then set the lens to 105mm and locked the exposure. My readings were locked at 1/125 second, f4, ISO 1600.

Then I started the video. It ran for about 20 secs and then got darker by at least one stop. I don't know what changed. My setup didn't appear to change.

The 1/125 speed setting was ignored. It used 1/33 second constantly before and after the brightness change. So the readings are pretty much ignored even after locking them.

I would need to do more tests but I suspect the discovery that it always uses the slowest shutter when over ISO 100 is true even when the lens is not locked and the focal length is long.

And you can forget about the 1/focal length rule. It is definitely ignored after the video starts.

[Josh Dahlberg]

Originally Posted by Mark Hahn

I would need to do more tests but I suspect the discovery that it always uses the slowest shutter when over ISO 100 is true even when the lens is not locked and the focal length is long.

And you can forget about the 1/focal length rule. It is definitely ignored after the video starts.

Nice work Mark. Once your findings are definitive you'll need to do a "5D Mark II Shutter Exposed! (Part III)' thread and get Chris to lock it down as a sticky.

This knowledge is essential!

[Jon Fairhurst]

I made some similar tests to Mark's, and the results basically agree. Unfortunately, my flash is slow (it turns on within a line or so, but fades slowly at the end.) Because of this, I just did rough line counts, eying the point at which the light started to fade. Sure enough, 1/40 displayed yielded 1/49. 1/50 and 1/60 yielded 1/93. I'll defer to Mark's numbers, as his flash is crisper.

The really good news is that my tests were done with HTC (Highlight Tone Priority) enabled. That limits the ISO to no lower than 200. I also captured two videos - one with HTC on and another with it off. Sure enough, the gain is roughly twice as high with HTC enabled.

So, what does all this mean (assuming Nikon or untwisted/mylar lenses)?

1) When shooting in low light, just dial the ISO to whatever you need. (by low light, I mean above 100 ISO normal or above 200 ISO with HTP enabled.) This will give you a consistent 1/33 (or so) shutter. Yeah, it's mushy, but you'll have no problem editing your stuff together.

2) When you want something closer to a film shutter outdoors or with lots of power, adjust for 1/40 and 100 ISO. Add ND filters as needed. It's not 180 degrees, but it's close (216 degrees.)

3) When you are shooting indoors, you can get an extra stop or so and maintain the 1/50 shutter by enabling HTP. Set to 1/40 and 200 ISO.

4) The camera supports faster shutter speeds starting at 1/100 with 1/50 displayed. Frankly, there's some conflicting data at 1/50, I'd adjust to 1/60 to be safe. At faster speeds, you can simply dial for exposure, or do tests to see if you are getting the result that you want. I'd lean toward practice, rather than numbers and theory.

BTW, to achieve HTP, go into the menu and select the custom functions (the Camera icon), use the wheel to select the 2nd submenu (Image), and use the wheel again to select the third variable (HTP). Hit the select button to enable/disable it.

So, filmmakers. Start buying lights or shoot outdoors, if you want a film-like shutter speed.

[Mark Hahn]

Originally Posted by Jon Fairhurst

I made some similar tests to Mark's, and the results basically agree. Unfortunately, my flash is slow (it turns on within a line or so, but fades slowly at the end.) Because of this, I just did rough line counts, eying the point at which the light started to fade. Sure enough, 1/40 displayed yielded 1/49. 1/50 and 1/60 yielded 1/93. I'll defer to Mark's numbers, as his flash is crisper.

The really good news is that my tests were done with HTC (Highlight Tone Priority) enabled. That limits the ISO to no lower than 200. I also captured two videos - one with HTC on and another with it off. Sure enough, the gain is roughly twice as high with HTC enabled.

So, what does all this mean (assuming Nikon or untwisted/mylar lenses)?

1) When shooting in low light, just dial the ISO to whatever you need. (by low light, I mean above 100 ISO normal or above 200 ISO with HTP enabled.) This will give you a consistent 1/33 (or so) shutter. Yeah, it's mushy, but you'll have no problem editing your stuff together.

2) When you want something closer to a film shutter outdoors or with lots of power, adjust for 1/40 and 100 ISO. Add ND filters as needed. It's not 180 degrees, but it's close (216 degrees.)

3) When you are shooting indoors, you can get an extra stop or so and maintain the 1/50 shutter by enabling HTP. Set to 1/40 and 200 ISO.

4) The camera supports faster shutter speeds starting at 1/100 with 1/50 displayed. Frankly, there's some conflicting data at 1/50, I'd adjust to 1/60 to be safe. At faster speeds, you can simply dial for exposure, or do tests to see if you are getting the result that you want. I'd lean toward practice, rather than numbers and theory.

BTW, to achieve HTP, go into the menu and select the custom functions (the Camera icon), use the wheel to select the 2nd submenu (Image), and use the wheel again to select the third variable (HTP). Hit the select button to enable/disable it.

So, filmmakers. Start buying lights or shoot outdoors, if you want a film-like shutter speed.

I'm happy to see I wasn't crazy. I am still pi**ed off that we are stuck with 1/33 at night.

But how did Laforet get low blur at night? I still want to do the combined strobe flash with moving object (blur) test. I can do the flash and then move something, like waving my hand.

[Jon Fairhurst]

Originally Posted by Mark Hahn

But how did Laforet get low blur at night? I still want to do the combined strobe flash with moving object (blur) test. I can do the flash and then move something, like waving my hand.

I'm wondering the same thing. I'm also wondering why the flash test shows 1/50 grouped with 1/60 (displayed), yet my turntable test and your fan test grouped 1/50 with 1/40.

We've got some more digging to do...

[Mark Hahn]

I apologize but the whole Laforet blur problem was nonsense. I calculated it wrong before.

It takes him 2 seconds to walk half the width of the screen. That is 16 (960/60) pixels per frame. His blur was close to that amount.

So we have pretty much done everything we can to understand the behavior of the camera with the f-stop locked. I'm sure it wouldn't be much harder to understand how the unlocked f-stop behaves also but I don't really care.

It behaves two ways depending on whether the ISO reads at 100 (200 with htp) or not. At ISO 100 the speed takes on a finite number of values depending on the speed reading which we can show in a table. Above ISO 100 the speed is always 1/33 (or 1/30).

I would like to point out that it misbehaves at times. I usually see 1/33 as the slowest speed, but I definitely saw a full 1/30 for at least one scene. Entries in the speed table for ISO 100 will vary. The reading 1/50 has shown both 1/50 and 1/100.

I suspect the variance it that even with the exposure locked, the camera feels free to change readings when the video starts. So if a reading is borderline, it can change when you start rolling. Locking the exposure works but that is all. It doesn't lock anything that makes up the exposure. We will just have to live with that.

Now that I am done studying this all I can say in summary is that the control of the video sucks more than I expected. I guess I will be shooting with a locked aperture using Mylar and with a constant speed of 1/33.

The only silver lining in this cloud is that we know 1/33 looks good in the video we've seen everywhere. Maybe that is part of the "lushness" we see in the video. I guess the zealots that want the "film-look" are just screwed. There is no way that I can see how you could reliably get the same 1/50 or even 1/60 in every scene.

Jon, you are a good writer, do you want to write the "Ultimate guide to 5D2 exposure behavior" and put it on your blog? We could all double check it and then post links to it. I don't have a blog and I think the info should be posted somewhere permanently.

I think the manual describes when the f-stop is changed so that could be thrown in also, even though the manual lies here and there.

[Mark Hahn]

Maybe having all night/dark shots at 1/33 and all day/bright shots at 1/50 would not be such a bad thing. Cutting between two such scenes is going to look different no matter what. Dark scenes could be lush and bright scenes could be sharp, timing-wise. It may look quite good actually.

[Klas Persson]

Is really the 1/focal length rule true? I mean as in, the shutter speed will be 1/50 when using a 50mm lens? Why is that? It doesn't make any sense?

Any way. If it actually is true why not just attach an af confirm chip to the adapter(nikon, m42 or what ever) which is programmed to tell the camera a 50mm lens is attched?

EDIT:

Originally Posted by Mark Hahn

And you can forget about the 1/focal length rule. It is definitely ignored after the video starts.

Ok... to hasty there. Will read this thread through properly now. :)

[Mark Hahn]

Originally Posted by Klas Persson

Is really the 1/focal length rule true? I mean as in, the shutter speed will be 1/50 when using a 50mm lens? Why is that? It doesn't make any sense?

Any way. If it actually is true why not just attach an af confirm chip to the adapter(nikon, m42 or what ever) which is programmed to tell the camera a 50mm lens is attched?

If you look back a few posts in this thread (I know it is hard to read) you will see that the 1/focal length is applied to the reading reported at the bottom of the screen, but that reading is totally ignored once shooting has started. So the whole rule is a non-issue.

[Chris Barcellos]

So I was trying to come up with some simple rules based on what you guys have come up with. I think I would like a bit more clarity in the findings you've developed, and I am wondering if this fits:


When shooting video with Nikon lenses or any lens where you are setting aperature manually:

Rule 1. Camera shoots at 1/33 of a second, any time the ISO is above 100, or above 200 with HTP mode adapted. There is no way around this no matter what shutter speed reads out on the LCD.

2. At ISO 100, or 200 with HTP set, you can adjust shutter speeds higher.

a. 1/40th gets you close to a 180 degree shutter effect.

b. 1/50th and up can get you anywhere from 1/50 to 1/100

Is this where we are at, in simple terms ?

[Mark Hahn]

Originally Posted by Chris Barcellos

So I was trying to come up with some simple rules based on what you guys have come up with. I think I would like a bit more clarity in the findings you've developed, and I am wondering if this fits:


When shooting video with Nikon lenses or any lens where you are setting aperature manually:

Rule 1. Camera shoots at 1/33 of a second, any time the ISO is above 100, or above 200 with HTP mode adapted. There is no way around this no matter what shutter speed reads out on the LCD.

2. At ISO 100, or 200 with HTP set, you can adjust shutter speeds higher.

a. 1/40th gets you close to a 180 degree shutter effect.

b. 1/50th and up can get you anywhere from 1/50 to 1/100

Is this where we are at, in simple terms ?

You nailed it.

The actual table for speeds with ISO 100 is ...

Reading, actual

25, 33 ?
30, 33 ?
40, 50
50, 50 or 100
60, 100
80, 100
100 100
125 125
160 160
200 200

60 was measured a total of one time so it may vary like 50. 40 and 50 were measured a lot of times. 80 was measured only twice but it is believable since 60 and 100 agreed.

It would be pretty easy to guarantee 100. It is a shame it is so fast. I don't think it would look good.

It appears that it runs at 50 or 100 at low readings and then runs at the indicated speed above 100. The point where it switches between 50 and 100 can vary.

[Chris Barcellos]

ReWrite:


When shooting video with Nikon lenses or any lens where you are setting aperature manually:

Rule 1. Camera shoots at 1/33 of a second, any time the ISO is above 100, or above 200 with HTP mode adapted. There is no way around this no matter what shutter speed reads out on the LCD.

Rule 2. At ISO 100, or 200 with HTP set, you can adjust shutter speeds higher.

a. 1/40th gets you close to a 180 degree shutter effect.

b. Actual shutter speed you will get are as follows:

25 -> 33 ?
30-> 33 ?
40 -> 50
50 -> 50 or 100
60 -> 100
80 -> 100
100 -> 100
125 -> 125
160 -> 160
200 -> 200

[Jon Oskar]

Originally Posted by Chris Barcellos

ReWrite:


When shooting video with Nikon lenses or any lens where you are setting aperature manually:

Rule 1. Camera shoots at 1/33 of a second, any time the ISO is above 100, or above 200 with HTP mode adapted. There is no way around this no matter what shutter speed reads out on the LCD.

Rule 2. At ISO 100, or 200 with HTP set, you can adjust shutter speeds higher.

a. 1/40th gets you close to a 180 degree shutter effect.

b. Actual shutter speed you will get are as follows:

25 -> 33 ?
30-> 33 ?
40 -> 50
50 -> 50 or 100
60 -> 100
80 -> 100
100 -> 100
125 -> 125
160 -> 160
200 -> 200

Is this regardless of AF confirm chip on a nikon lens?

[Mark Hahn]

Originally Posted by Chris Barcellos

ReWrite:


When shooting video with Nikon lenses or any lens where you are setting aperature manually:

Rule 1. Camera shoots at 1/33 of a second, any time the ISO is above 100, or above 200 with HTP mode adapted. There is no way around this no matter what shutter speed reads out on the LCD.

Rule 2. At ISO 100, or 200 with HTP set, you can adjust shutter speeds higher.

a. 1/40th gets you close to a 180 degree shutter effect.

b. 1/50th and up can get you anywhere from 1/50 to 1/200, as follows:

25 -> 33 ?
30-> 33 ?
40 -> 50
50 -> 50 or 100
60 -> 100
80 -> 100
100 -> 100
125 -> 125
160 -> 160
200 -> 200

It looks good except for some small things.

2.a isn't quite true and I don't think it really belongs in this kind of reference information.

aperature is misspelled.

Feel free to post this on any forum. Just give Jon and me some credit. Also link to this thread.

[Jon Fairhurst]

Chris, most of what you wrote is true, except this:

Originally Posted by Chris Barcellos

b. 1/50th and up can get you anywhere from 1/50 to 1/100

It looks like 1/50 displayed yields 1/100, but there is some conflicting evidence here. I'd go with 1/60 or 1/80 displayed for a 1/100 shutter.

And I'd add...

c. Higher displayed shutter speeds (1/125 and up) deliver ever higher speeds, well beyond the 1/125 limit stated in the manual.