Author Topic: Expo override does not set aperture correctly on 5D2 + USM lens  (Read 517 times)

tajino

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Expo override does not set aperture correctly on 5D2 + USM lens
« on: October 05, 2017, 09:00:36 AM »
On 5D mark II and USM lens, in Liveview Photo ExpSim with Expo Override set to On, the aperture does not get set correctly. For example a f/32 would only drive the aperture to f/5.6.

Tested on ML nightly 5D2 212 2017-10-03 all the way back to 2016 builds, all showing the same results.

Lens tested :
Canon 70-200mm f2.8 L IS II
Canon 24-105mm f4 L IS
Canon 16-35mm f/2.8 L II
Canon 100mm macro f/2.8 L

Is this a known issue?

I'm trying to get this working for FRSP macro focus stacking, can't untwist the lens because need ML to drive focus.

tajino

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #1 on: October 06, 2017, 04:31:55 AM »
Anyone with 5D mark 3 or other model able to get Expo Override to set aperture correctly while in liveview Photo ExpSim mode? Just curious.

Can anyone please try this : While in liveview Photo ExpSim mode, set Expo Override On, turn the AV dial while looking at the lens aperture from the front of lens, see if there are any changes to the aperture opening?

Thanks!

tajino

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #2 on: October 07, 2017, 08:38:15 PM »
Since it is documented here https://wiki.magiclantern.fm/userguide#expo_override which enables "Full-time DOF preview in photo mode, without blocking certain keys."

I'm just curious if there are any undocumented exceptions to watch out for, like certain combination of camera and lens, like for example in my case a 5D2 + EF USM L lens?

Hope someone can shed some light on this, thanks!

Looks like this issue has been brought up in this post https://www.magiclantern.fm/forum/index.php?topic=12523.msg145567#msg145567

mothaibaphoto

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #3 on: October 08, 2017, 04:21:06 AM »
This is known issue for STM lenses.
Canon 16-35mm f/2.8 L II works pretty well for me with FRSP.

tajino

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #4 on: October 08, 2017, 05:19:39 PM »
This is known issue for STM lenses.
Canon 16-35mm f/2.8 L II works pretty well for me with FRSP.

Which camera are you using it on?

Can you confirm if Expo Override did set the aperture correctly while in LV Photo ExpSim mode?

Try this :
0. put camera into M mode, set Expo Override to ON
1. Set your 16-35mm AV to f/22, TV at 1/30 s, ISO at 100
2. Start LV, set LV mode to photo ExpSim, leave the LV mode menu open, so you could later flip between photo and movie with the thumb wheel
3. Look at the aperture opening from the front of lens
4. Switch between photo ExpSim and movie mode with the thumb wheel while observing the aperture opening.

Did you see any changes to the size of the aperture opening while flipping between the 2 modes?

Thanks in advance!

tajino

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #5 on: October 08, 2017, 05:48:18 PM »
After some searching, found this post, 5D3 + EF 24mm f/2.8 IS USM, aperture in Expo Override does not work.

https://www.magiclantern.fm/forum/index.php?topic=12523.msg148354#msg148354

Any chance to have this looked into?
Sorry to ask if this is already a known unfixable problem/limitation.

a1ex

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #6 on: October 08, 2017, 06:01:56 PM »
5D3 with EF-S 24mm f/2.8 STM also has the issue. The 50/1.8 used to work... while it lasted.

The fix is not obvious to me, but I wouldn't call it unfixable, just difficult. My previous experiments trying to set aperture manually (with direct MPU messages) were not successful; I've managed to move the focus ring, but not the aperture.

tajino

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #7 on: October 08, 2017, 10:22:37 PM »
Hi a1ex, thanks for your reply.

STM has issue is one thing, but why are my 5D2 + USM combination also having the same issue?

When you have time, can you try this out :
0. put the camera into M mode, set Expo Override to ON
1. Set AV to f/22, TV at 1/30 s, ISO at 100
2. Start LV, set LV mode to photo ExpSim, leave the LV mode menu open, so you could later flip between photo and movie with the thumb wheel
3. Look at the aperture opening from the front of lens
4. Switch between photo ExpSim and movie mode with the thumb wheel while observing the aperture opening.

Did you see any changes to the size of the aperture opening while flipping between the 2 modes? If no change in aperture size, what are the lenses that works?

Finally, is there a possibility of a crop_rec_4k build for 5D2? If not possible is it due to 5D2 hardware and the lack of pixel binning in movie mode?


reddeercity

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #8 on: October 09, 2017, 04:10:12 AM »
..... is there a possibility of a crop_rec_4k build for 5D2?
3K/UHD 5D2 Raw development and Other Digic IV Cams  
Contributions are Welcome

mothaibaphoto

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #9 on: October 09, 2017, 09:52:49 AM »
16-35mm f/2.8 L II works on 5D MKII and MKIII(I have both).
I also have 24 and 35 IS STM wich exhibit this behavior.
I suspect you have 16-35mm f/2.8 L III (newer model) wich is possibly "STM" too.
You can try FRSP in video mode. as far as I remember, it works, just not possible to set exposures longer than framerate.

tajino

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Re: Expo override does not set aperture correctly on 5D2 + USM lens
« Reply #10 on: October 10, 2017, 12:24:21 AM »
I did the test again on more lenses, here are my findings :

Lenses that work :
Canon 24-105mm f/4 L IS USM mark I
Canon 16-35mm f/2.8 L USM mark II
Canon 50mm f/1.4 USM
Sigma 8mm f/3.5 EX DG Circular Fisheye

Lenses that do not work :
Canon 100mm f/2.8 L macro USM Mark I
Canon 70-200mm f/2.8 L IS USM Mark II

This sort of concludes that the newer USM lens could be using STM which doesn't work with Expo Override.

You can try FRSP in video mode. as far as I remember, it works, just not possible to set exposures longer than framerate.

FRSP isn't allowed in video mode on 5D mark II, or is there a workaround to that? Only SSP (simple silent pic) works in video mode.

3K/UHD 5D2 Raw development and Other Digic IV Cams  
Contributions are Welcome

Interesting thread, will look into it.