Wild guess: If the camera doesn't know the real aperture, and it reports 00, then these results hold true.

I think 1/50 needs to say "50 or 100". I've seen each multiple times, as you have also.

Yes, the table stopped at 200 only because the error in my readings started getting really bad. If you go back to my long table you can see the actual measurements for 250 and 300.

It reports 2.0 with the chip

How's this for a further rewrite

ReWrite Draft 2:


When shooting video with Nikon lenses or any lens where you are setting aperture 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.

1/25 -> 1/33 ?
1/30-> 1/33 ?
1/40 -> 1/50
1/50 -> 1/50 or 1/100
1/60 -> 1/100
1/80 -> 1/100
1/100 -> 1/100
1/125 -> 1/125
1/160 -> 1/160
1/200 -> 1/200

Rule 3. With a non-aperture control lenses, higher shutter speeds will also be attained, despite Canon indications of limited speed of video at 1/125 for video shooting.

Looks good again.

I'd pull the 1/25 and 1/33. I don't know why I added them. You can't get them at ISO 100. You have to go up to ISO 3200 to get speeds below 40.

Rule 3 has some grammar issues (you don't want grammar Nazi attacks). If you forgive me here is a rewrite ...

Rule 3. With a non-aperture control lens, even higher shutter speeds than the 200 shown can be attained, despite Canon's indication of the limited speed of 1/125.

Oh, you also need to somehow indicate what the left side and right side of the table means. I might be getting a bit picky here.

Since I don't have such a chip, you will have to measure it yourself. It is actually quite easy. Don't let the number of steps below fool you. I went into great detail.

1) Focus on a blank wall (or actually anything).

2) Get the readings you want, however you can, and lock the exposure.

3) Start the video and then say the settings out loud. My wife was laughing for me sitting there announcing numbers. This is the only way I could tell the tests apart later.

4) Set a strobe flash to manual, with its lowest power setting.

5) Flash it and watch the LCD. Repeat until you see a dark band or light band near the middle of the screen.

6) Pull the video into any editor that can output single frames.

7) Find the flashes (looking at the sound track may help).

8) If you see a light bar, then you caught the entire exposure in one frame and you should save it. If you see two frames in a row with light at the bottom of the first and at the top of the second then save both frames.

9) Count the total light lines of video. If it was across two frames, add 367 lines for the time between frames.

10) Divide 43,410 by the number of bright lines and voila, you have the speed.

Note that I did the line counting by using photoshop, opening the "info" pane, and just waving the pointer over the top and bottom of the bright areas. This made it easy.

Here is final of the finding Mark Hahn developed from his shutter speed testing. I'd sure like to see Chris Hurd put these somewhere for easy reference for many shooters.

MARK HAHNS FINDINGS:

When shooting video with Nikon lenses or any lens where you are setting aperture 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.


1/40 -> 1/50
1/50 -> 1/50 or 1/100
1/60 -> 1/100
1/80 -> 1/100
1/100 -> 1/100
1/125 -> 1/125
1/160 -> 1/160
1/200 -> 1/200

Rule 3. With a non-aperture control lens, even higher shutter speeds than the 200 shown can be attained, despite Canon's indication of the limited speed of 1/125.

Credit can be more subtle, like at the end: "From tests performed by Jon Fairhurst and Mark Hahn. See thread xxx" My name on the top in all caps looks like a bit more bragging than I'm comfortable with.

P.S. Thanks for putting this together.

I apologize for all the edit requests, but this thing might as well be perfect. May I suggest adding a new sentence to the end of rule 2 so it reads ...

Rule 2. At ISO 100, or 200 with HTP set, you can adjust shutter speeds. The following table shows the LCD reading on the left and the right shows the actual shutter speed the camera will use.

Are you guys talking about the shutter speed displayed on the camera once you hit record and slightly press the photo button or the shutter speed locked in prior to hitting record video. Because the value you lock prior to rec. obviously isn't always what shows up once recording. And now it seems that even the aperture displayed while recording is not what it says. So now we have three variables, could you guys elaborate or specify more narrowly what the rules mean?

Is the shutter displayed during the recording the left cell, and the right cell what the camera is actually recording according to the testing?

Mark:

No problem with rewrites, just trying to get something down that is simple to follow. Check this out:


From tests performed by Jon Fairhurst and Mark Hahn, the following findings have been made:

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

Rule 1. Camera shoots at 1/33 of a second, any time the ISO is above 100, or above 200 with HTP mode employed. 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. The following table shows the LCD reading on the left and the right shows the actual shutter speed the camera will use.

LCD -> Actual
Reads

1/40 -> 1/50
1/50 -> 1/50 or 1/100
1/60 -> 1/100
1/80 -> 1/100
1/100 -> 1/100
1/125 -> 1/125
1/160 -> 1/160
1/200 -> 1/200

Rule 3. With a non-aperture control lens, even higher shutter speeds than the 200 shown can be attained, despite Canon's indication of the limited shutter speed of 1/125.

The tests all assume manually controlled aperture. The three common methods are:

* A Nikon lens with an aperture ring, mounted with an adapter,
* A Canon lens untwisted from the body (moderately unsafe), or
* A Canon lens with the contacts separated from the body with an insulator, such as mylar.

In each of these cases, the aperture is displayed as 00 and is not controlled or read by the camera. This reduces the variables from three to two, which really simplifies things.

Looks good to me.

Me too. Thanks for putting this together.