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-   -   Does the focal length rule apply in video mode? (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/142623-does-focal-length-rule-apply-video-mode.html)

Mathieu Kassovitz January 28th, 2009 11:43 PM

Does the focal length rule apply in video mode?
 
I've read quite contradictory reports.

Focal length = auto shutter speed chosen by the camera.

Also for the video? Or is it only for photos during video recording?

Mark Hahn January 28th, 2009 11:56 PM

Quote:

Originally Posted by Mathieu Kassovitz (Post 1002962)
I've read quite contradictory reports.

Focal length = auto shutter speed chosen by the camera.

Also for the video? Or is it only for photos during video recording?

The 5D2 algorithm for settings is a complicated monster. I think it is slowly being understood, but not completely. Apparently the 1/FL rule is used in part of the algorithm, which makes absolutely no sense.

Mathieu Kassovitz January 29th, 2009 12:07 AM

What exactly does it mean? Not always in movie mode? If not, when? In which circumstances?

Mark Hahn January 29th, 2009 01:04 AM

Quote:

Originally Posted by Mathieu Kassovitz (Post 1002976)
What exactly does it mean? Not always in movie mode? If not, when? In which circumstances?

I was referring to the settings in video mode, before you lock exposure.

The rule is also used in the camera in still mode when using auto-iso.

Toenis Liivamaegi January 29th, 2009 07:22 AM

I'm experiencing that automatic shutter speed=focal length always when I attach EF electronic lenses, one might argue that 1/20th isn't possible and is same as the 1/30th but still it uses slower shutter for wides and a bit faster for longer lenses requiring me to double the lightning to shoot with longer lens or to use one stop faster tele lens.
Locking different electronically connected lenses at same shutter speed is a pain but not so with disconnected and manual lenses.

One crazy thing also is that the rule applies for zoom lenses even when AE lock is engaged! This focal length change in middle of a take will drop frames as camera can not process the info for its automatics fast enough, this is utterly disturbing. Fast manual zooms are also not monitorable if so to speak because the cam can not show it fast enough.

EF compatible lenses are not compatible for movie making alas you disable the electronics.
And please don't use the twisting method, sooner or later it will ruin one of your lenses.
If not so http://www.autonomicum.com/forums_up/MVI_0143.MOV then in some other way.


Cheers,
T

Mathieu Kassovitz January 29th, 2009 11:35 AM

Quote:

Originally Posted by Mark Hahn (Post 1003006)
I was referring to the settings in video mode, before you lock exposure.

Quote:

Originally Posted by Toenis Liivamaegi (Post 1003103)
One crazy thing also is that the rule applies for zoom lenses even when AE lock is engaged!

Even when it is locked? No work-around?

Mark Hahn January 29th, 2009 12:02 PM

Quote:

Originally Posted by Toenis Liivamaegi (Post 1003103)
I'm experiencing that automatic shutter speed=focal length always when I attach EF electronic lenses, one might argue that 1/20th isn't possible and is same as the 1/30th but still it uses slower shutter for wides and a bit faster for longer lenses requiring me to double the lightning to shoot with longer lens or to use one stop faster tele lens.
Locking different electronically connected lenses at same shutter speed is a pain but not so with disconnected and manual lenses.

One crazy thing also is that the rule applies for zoom lenses even when AE lock is engaged! This focal length change in middle of a take will drop frames as camera can not process the info for its automatics fast enough, this is utterly disturbing. Fast manual zooms are also not monitorable if so to speak because the cam can not show it fast enough.

EF compatible lenses are not compatible for movie making alas you disable the electronics.
And please don't use the twisting method, sooner or later it will ruin one of your lenses.
If not so http://www.autonomicum.com/forums_up/MVI_0143.MOV then in some other way.


Cheers,
T

Is it possible you are using a variable aperture lens? They have to change the opeing when you zoom no matter what.

Toenis Liivamaegi January 30th, 2009 09:46 AM

Quote:

Originally Posted by Mark Hahn (Post 1003266)
Is it possible you are using a variable aperture lens? They have to change the opeing when you zoom no matter what.

I'm using variable aperture lens but this is where it gets crazy - the cam dials in faster shutter for smaller aperture, WTF, even when AE lock is angaged.
It shows 1/30th for 20mm f5.6 end and 1/50th f5.6 for the tele end and corrects the image to that, and it is visible.

When I disconnect the lens everything turns to normal and I can shoot with constant values.

T

Mark Hahn January 30th, 2009 11:40 AM

Quote:

Originally Posted by Toenis Liivamaegi (Post 1003839)
When I disconnect the lens everything turns to normal and I can shoot with constant values.

So the moral to this story is, Always Disconnect The Lens.

I always feel in full control when the lens is disconnected. I feel I understand its behaviour well enough to get whatever I want. Too little light in and it runs the ISO up (but reports it as speed going down), too much light and the speed goes up. In the middle I get 1/45 (reported as 1/40) with adjustable ISO. Luckily 1/45 is just what I want.

Mathieu Kassovitz January 30th, 2009 01:32 PM

Wouldn't it work with tape only on a few pins for keeping the auto focus and IS?

Kenko "Taped" photo - lightrules photos at pbase.com

1.4xTC Test: Tamron "F" v. Kenko "Pro 300" Photo Gallery by lightrules

Bob on 05-Nov-2006 13:13
I am considering purchasing the 100-400MM IS and based on what I have read I will need to tape the 3 pins on the TC in order for me to get the 100-400MM to auto focus.

Jon Fairhurst January 30th, 2009 03:18 PM

Quote:

Originally Posted by Mathieu Kassovitz (Post 1004006)
Wouldn't it work with tape only on a few pins for keeping the auto focus and IS?

The risk is that the tape falls off and gums up your shutter or sensor. I taped a cheap lens - and now I have no idea where the tape ended up.

I like the mylar ring idea much better. Maybe some holes can be cut for power. The key is to find a way to keep it from rotating. The real pain is that you have to mount the lens without the mylar to set the aperture, hold the DOF button, remove the lens, and insert the mylar.

It's workable, but a real pain. It's easier to untwist (though you risk dropping it.) And if you untwist, you might as well get a Nikon manual and adapter.

The only sensible solution is for Canon to upgrade the firmware so we can use their lenses without all this silliness. Adding manual control won't fundamentally change the pro video camera market (we still have 30p, aliasing, poor audio, the lack of knobs, and no video-worthy autofocus), but it will change the market for Canon lenses.

The more Nikon lenses I buy, the more likely my next body is a Nikon.

It's funny. Normally when I make a big purchase, I'm proud of it. I become a fan of the company. I've never experienced this level of product - and company - ambivalence before. Don't get me wrong. I'd buy this camera again. It's the best product out there for what we do. But making their customers jump through unnecessary hoops shot after shot, and driving us to the competition's lenses is an unbelievably poor business move.

Then again, if they make this one change, I'll be singing Canon's praises. And I'll still remind people to think twice about dumping pro video cameras for the 5D. It's the right camera for many of us, but many jobs still require a true video cam.

Toenis Liivamaegi January 30th, 2009 04:34 PM

Quote:

Originally Posted by Mathieu Kassovitz (Post 1004006)
Wouldn't it work with tape only on a few pins for keeping the auto focus and IS?

I haven't figured out how to disable only some of the pins, I tried every freaking way and focus or IS power just was on or off no "half life" there.

T

Mathieu Kassovitz January 30th, 2009 05:18 PM

Quote:

Originally Posted by Toenis Liivamaegi (Post 1004125)
I haven't figured out how to disable only some of the pins, I tried every freaking way and focus or IS power just was on or off no "half life" there.

T

Well, the idea would be to disable the focal length = shutter speed rule at least.

Here's an example. You disable the last three pins of a teleconverter (TC), this will allow to keep the aperture. Disabling the three pins, you can keep the fastest aperture (f/4 for example) provided by the lens, instead the fastest aperture on the TC (f/5.6 for a 1.4x, f/8 for a 2x). Keeping the auto focus and IS anyhow.

So, you'll cheat the camera (nothing else than aperture). Isn't it possible the same with this body? Did you ever try to disable something similar such as those last three pins for instance?

Toenis Liivamaegi January 30th, 2009 06:20 PM

Quote:

Originally Posted by Mathieu Kassovitz (Post 1004151)
Well, the idea would be to disable the focal length = shutter speed rule at least.

Here's an example. You disable the last three pins of a teleconverter (TC), this will allow to keep the aperture. Disabling the three pins, you can keep the fastest aperture (f/4 for example) provided by the lens, instead the fastest aperture on the TC (f/5.6 for a 1.4x, f/8 for a 2x). Keeping the auto focus and IS anyhow.

So, you'll cheat the camera (nothing else than aperture). Isn't it possible the same with this body? Did you ever try to disable something similar such as those last three pins for instance?

Yes, I tried. But the communication is either on or off - how bad it is for me not to be able to use my 85mm 1.2 L or other "L" full time "USM" manual focus lens for video. They tried hard but now is the time for evolution and not the time for greed.

See here to relax a bit on that Japanese capitalist act Nagasaki Journey: 1 of 25

Every day that we don't evolve we are justifying God's suicide that took place when the old testament was formed, and every one of us should know why as we are the reason behind it. Then there's another reporter who told me that when he blew up an unbelieving pagan kindergarten in hope to get all those virgins he found out that all the virgins had also killed their selves to get onto the next level and so on and so on...

... in the other hand thanks to Canon I'm becoming a better artist that could be considered priceless.

T

Christopher Witz January 30th, 2009 06:46 PM

Just get yourself a singh ray ari-nd filter and enjoy your 85 1.2, I know I do.... no problem getting it wide open with it.

here's some footage I've shot with a few scenes using it wide open....

Amherst - Here and Now By chris witzke On ExposureRoom

Misty... 1st draft By chris witzke On ExposureRoom

I have no desire to put non EF lenses on my 5d2.

Mathieu Kassovitz January 30th, 2009 07:10 PM

Yes, a ND filter is the solution. Although, it seems there isn't any solution for the focal length = shutter speed rule. Unless, the manual mode or twisted lens.

Toenis Liivamaegi January 30th, 2009 07:17 PM

Back to the topic
 
Chris, how can you get ISO 800 with 1/50 shutter with EF lenses other than with the 50mm one?

Maybe it's all the same from 30th to 100th shutter but I'm loosing more light with 1.2 85mm than with 50mm 1.8 because the apparent focal length to shutter speed rule.

Rack focusing is also almost impossible with USM fulltime electronic manual focus that might be the case of 1.2 L only. Straight from the cam http://www.autonomicum.com/forums_up/MVI_0017_bela.MOV (hear the inconstancy of my hand turning the electronic focusing barrel).

T

Mathieu Kassovitz January 30th, 2009 07:24 PM

Quote:

Originally Posted by Jon Fairhurst (Post 1004075)
The risk is that the tape falls off and gums up your shutter or sensor. I taped a cheap lens - and now I have no idea where the tape ended up.

I like the mylar ring idea much better. Maybe some holes can be cut for power. The key is to find a way to keep it from rotating.

Tape or mylar. You are correct. The mylar ring idea is better.

Christopher Witz January 30th, 2009 07:35 PM

Quote:

Originally Posted by Toenis Liivamaegi (Post 1004193)
Chris, how can you get ISO 800 with 1/50 shutter with EF lenses other than with the 50mm one?

Maybe it's all the same from 30th to 100th shutter but I'm loosing more light with 1.2 85mm than with 50mm 1.8 because the apparent focal length to shutter speed rule.

Rack focusing is also almost impossible with USM fulltime electronic manual focus that might be the case of 1.2 L only. Straight from the cam http://www.autonomicum.com/forums_up/MVI_0017_bela.MOV (hear the inconstancy of my hand turning the electronic focusing barrel).

T

I've been seeing 1/30th most of the time with my 85 1.2 II....

Mathieu Kassovitz January 31st, 2009 01:09 PM

There is who has mentioned the focal length = auto shutter speed rule is misleading because it applies only for taking pictures during video recording. Is that so?

Manual Control. The Truth !

Shutter, Aperture, ISO-Display: Are they all wrong?


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