December 19, 2014, 05:24:21 AM

Author Topic: the future of 1.2 L lenses ?  (Read 10849 times)

CarlTN

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Re: the future of 1.2 L lenses ?
« Reply #30 on: September 18, 2013, 02:55:08 PM »

I was comparing two contemporary cameras, the 5DIII and 6D, not a 5-year old camera that has been replaced.  But yes, the 6D is a fantastic camera, for it's price.   My Subaru is a fantastic car for its price, as well. It can go through over a foot of snow on the driveway, with drifts as high as the hood of the car, if I need to get out before the plow service comes. It even has heated seats to keep my butt warm.  But a well-equipped Volvo (5DIII) would be better, and a well equipped Mercedes (1D X) would be better still.  The point is, while the Subaru meets my needs as a car, the 6D does not meet my needs as a camera.


Glad we can agree on something!  It's amusing you compare the 5D3 to a Volvo, thanks for that!

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Re: the future of 1.2 L lenses ?
« Reply #30 on: September 18, 2013, 02:55:08 PM »

cayenne

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Re: the future of 1.2 L lenses ?
« Reply #31 on: September 18, 2013, 03:42:17 PM »
I just put in an order to lensrental.com for the 50L f/1.2

I'm actually going to need it for a video shoot with the 5D3 this weekend (see other thread about shooting in dark places like bars)....

I'm anxious to see how it works for video, and I'm getting it for 7 days and shooting stills too. I've been wanting this lens, so this is a good chance to try it out.

I've hear the main problem with this lens is a back-focusing problem.

Can someone describe to me what exactly this problems is...how it happens and what I should look for when shooting stills with it to see if I see this happening and how to avoid or shoot around it?

I'm guessing this isn't a problem shooting video with it, since that is all manual focus....but I'd really appreciate a nice primer on what to look for in the backfocusing I've read about....

Thanks!!

cayenne

neuroanatomist

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Re: the future of 1.2 L lenses ?
« Reply #32 on: September 18, 2013, 04:03:44 PM »
I just put in an order to lensrental.com for the 50L f/1.2

I'm actually going to need it for a video shoot with the 5D3 this weekend (see other thread about shooting in dark places like bars)....

I'm anxious to see how it works for video, and I'm getting it for 7 days and shooting stills too. I've been wanting this lens, so this is a good chance to try it out.

I've hear the main problem with this lens is a back-focusing problem.

Can someone describe to me what exactly this problems is...how it happens and what I should look for when shooting stills with it to see if I see this happening and how to avoid or shoot around it?

I'm guessing this isn't a problem shooting video with it, since that is all manual focus....but I'd really appreciate a nice primer on what to look for in the backfocusing I've read about....

Thanks!!

cayenne

It's not really a back focus issue, but rather focus shift.  No issue when shooting wide open, but when you stop down a bit, the focal plane shifts backward. This occurs because AF is done wide open, then the lens is stopped down as the shot is taken - you're correct that it will have no effect in manually focused video, as long as you're focusing in Live View

The issue is most evident with very close subjects, and is mitigated as you stop down to the point where the deeper DoF overcomes the focus shift.
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cayenne

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Re: the future of 1.2 L lenses ?
« Reply #33 on: September 18, 2013, 04:36:22 PM »
I just put in an order to lensrental.com for the 50L f/1.2

I'm actually going to need it for a video shoot with the 5D3 this weekend (see other thread about shooting in dark places like bars)....

I'm anxious to see how it works for video, and I'm getting it for 7 days and shooting stills too. I've been wanting this lens, so this is a good chance to try it out.

I've hear the main problem with this lens is a back-focusing problem.

Can someone describe to me what exactly this problems is...how it happens and what I should look for when shooting stills with it to see if I see this happening and how to avoid or shoot around it?

I'm guessing this isn't a problem shooting video with it, since that is all manual focus....but I'd really appreciate a nice primer on what to look for in the backfocusing I've read about....

Thanks!!

cayenne

It's not really a back focus issue, but rather focus shift.  No issue when shooting wide open, but when you stop down a bit, the focal plane shifts backward. This occurs because AF is done wide open, then the lens is stopped down as the shot is taken - you're correct that it will have no effect in manually focused video, as long as you're focusing in Live View

The issue is most evident with very close subjects, and is mitigated as you stop down to the point where the deeper DoF overcomes the focus shift.

Thank you (as usual) for the excellent info and explanation!!
:)

Is there a set of distances vs f/stops where the focus shift classically happens for everyone on this lens, or does it vary a bit from lens/camera combo to lens/camera combo?

I have the 5D3 that I'll be pairing with it.  Is there any way to avoid this focus shifting other than not shoot as x feet with f/x.y  ?

Thanks in advance,

C

CarlTN

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Re: the future of 1.2 L lenses ?
« Reply #34 on: September 18, 2013, 07:08:54 PM »
I just put in an order to lensrental.com for the 50L f/1.2

I'm actually going to need it for a video shoot with the 5D3 this weekend (see other thread about shooting in dark places like bars)....

I'm anxious to see how it works for video, and I'm getting it for 7 days and shooting stills too. I've been wanting this lens, so this is a good chance to try it out.

I've hear the main problem with this lens is a back-focusing problem.

Can someone describe to me what exactly this problems is...how it happens and what I should look for when shooting stills with it to see if I see this happening and how to avoid or shoot around it?

I'm guessing this isn't a problem shooting video with it, since that is all manual focus....but I'd really appreciate a nice primer on what to look for in the backfocusing I've read about....

Thanks!!

cayenne

It's not really a back focus issue, but rather focus shift.  No issue when shooting wide open, but when you stop down a bit, the focal plane shifts backward. This occurs because AF is done wide open, then the lens is stopped down as the shot is taken - you're correct that it will have no effect in manually focused video, as long as you're focusing in Live View

The issue is most evident with very close subjects, and is mitigated as you stop down to the point where the deeper DoF overcomes the focus shift.

Thank you (as usual) for the excellent info and explanation!!
:)

Is there a set of distances vs f/stops where the focus shift classically happens for everyone on this lens, or does it vary a bit from lens/camera combo to lens/camera combo?

I have the 5D3 that I'll be pairing with it.  Is there any way to avoid this focus shifting other than not shoot as x feet with f/x.y  ?

Thanks in advance,

C

You should be able to make the camera autofocus during live view while shooting video.  At least...I have done it with the 6D (the 5D3 should work similarly should it not?).  It helps if you are shooting a situation where the ambient noise overwhelms the noise from the lens focus motor. 

cayenne

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Re: the future of 1.2 L lenses ?
« Reply #35 on: September 19, 2013, 11:13:45 AM »
I just put in an order to lensrental.com for the 50L f/1.2

I'm actually going to need it for a video shoot with the 5D3 this weekend (see other thread about shooting in dark places like bars)....

I'm anxious to see how it works for video, and I'm getting it for 7 days and shooting stills too. I've been wanting this lens, so this is a good chance to try it out.

I've hear the main problem with this lens is a back-focusing problem.

Can someone describe to me what exactly this problems is...how it happens and what I should look for when shooting stills with it to see if I see this happening and how to avoid or shoot around it?

I'm guessing this isn't a problem shooting video with it, since that is all manual focus....but I'd really appreciate a nice primer on what to look for in the backfocusing I've read about....

Thanks!!

cayenne

It's not really a back focus issue, but rather focus shift.  No issue when shooting wide open, but when you stop down a bit, the focal plane shifts backward. This occurs because AF is done wide open, then the lens is stopped down as the shot is taken - you're correct that it will have no effect in manually focused video, as long as you're focusing in Live View

The issue is most evident with very close subjects, and is mitigated as you stop down to the point where the deeper DoF overcomes the focus shift.

Thank you (as usual) for the excellent info and explanation!!
:)

Is there a set of distances vs f/stops where the focus shift classically happens for everyone on this lens, or does it vary a bit from lens/camera combo to lens/camera combo?

I have the 5D3 that I'll be pairing with it.  Is there any way to avoid this focus shifting other than not shoot as x feet with f/x.y  ?

Thanks in advance,

C

You should be able to make the camera autofocus during live view while shooting video.  At least...I have done it with the 6D (the 5D3 should work similarly should it not?).  It helps if you are shooting a situation where the ambient noise overwhelms the noise from the lens focus motor.

Sorry, I was talking two separate issues....

I was asking my questions about how to avoid focus shifting when shooting stills.

For my video needs this weekend, I'll be shooting fully manual focus through LiveView.

Hmm..I didn't think the 5D3 had autofocus with video...?

C

Skirball

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Re: the future of 1.2 L lenses ?
« Reply #36 on: September 19, 2013, 12:28:27 PM »

I was comparing two contemporary cameras, the 5DIII and 6D, not a 5-year old camera that has been replaced.  But yes, the 6D is a fantastic camera, for it's price.   My Subaru is a fantastic car for its price, as well. It can go through over a foot of snow on the driveway, with drifts as high as the hood of the car, if I need to get out before the plow service comes. It even has heated seats to keep my butt warm.  But a well-equipped Volvo (5DIII) would be better, and a well equipped Mercedes (1D X) would be better still.  The point is, while the Subaru meets my needs as a car, the 6D does not meet my needs as a camera.


Glad we can agree on something!  It's amusing you compare the 5D3 to a Volvo, thanks for that!

To each their own.  If my needs are for a rally car, I'll take the Suby over the Volvo or Merc any day of the week.

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Re: the future of 1.2 L lenses ?
« Reply #36 on: September 19, 2013, 12:28:27 PM »

CarlTN

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Re: the future of 1.2 L lenses ?
« Reply #37 on: September 19, 2013, 04:05:10 PM »

I was comparing two contemporary cameras, the 5DIII and 6D, not a 5-year old camera that has been replaced.  But yes, the 6D is a fantastic camera, for it's price.   My Subaru is a fantastic car for its price, as well. It can go through over a foot of snow on the driveway, with drifts as high as the hood of the car, if I need to get out before the plow service comes. It even has heated seats to keep my butt warm.  But a well-equipped Volvo (5DIII) would be better, and a well equipped Mercedes (1D X) would be better still.  The point is, while the Subaru meets my needs as a car, the 6D does not meet my needs as a camera.


Glad we can agree on something!  It's amusing you compare the 5D3 to a Volvo, thanks for that!

To each their own.  If my needs are for a rally car, I'll take the Suby over the Volvo or Merc any day of the week.

Speaking of rally cars...the only channel on directv that seems to show any of WRC now is 214, and that's in standard def...very soft and letterboxed.  Now that Speed channel has gone extinct, it's time for someone else to make a new speed channel and do it right this time! 

Marsu42

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Re: the future of 1.2 L lenses ?
« Reply #38 on: September 19, 2013, 05:50:40 PM »
There are many complains about the 50L softness at 1.2 and the slow USM moter of 85L

Doesn't matter, since Nikon doesn't build f1.2 lenses for their system Canon will keep them coming :-p ... no matter if f1.2 with current sensors is really necessary or how many people actually are able to focus them wide open.

neuroanatomist

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Re: the future of 1.2 L lenses ?
« Reply #39 on: September 19, 2013, 05:59:30 PM »
Doesn't matter, since Nikon doesn't build f1.2 lenses for their system Canon will keep them coming :-p ... no matter if f1.2 with current sensors is really necessary or how many people actually are able to focus them wide open.

...or how much Canon has to secretly push the ISO to compensate for light lost due to the extreme oblique angle of light from an f/1.2 lens, especially since higher sensor pixel density means more push is needed.
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steliosk

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Re: the future of 1.2 L lenses ?
« Reply #40 on: September 20, 2013, 06:38:54 AM »
The only reason to buy 1.2 glass is the DOF!

the f/1.2 world is way too different than the f/2.8...

many thanks for your answers!
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Re: the future of 1.2 L lenses ?
« Reply #41 on: September 20, 2013, 08:08:43 AM »
Doesn't matter, since Nikon doesn't build f1.2 lenses for their system Canon will keep them coming :-p ... no matter if f1.2 with current sensors is really necessary or how many people actually are able to focus them wide open.

...or how much Canon has to secretly push the ISO to compensate for light lost due to the extreme oblique angle of light from an f/1.2 lens, especially since higher sensor pixel density means more push is needed.
No, you're not getting away with that, Neuro!

In an earlier thread, you objected to my saying something like "secretly" about this issue, by retorting that it is explained in some documentation somewhere (I forget the link), and is therefore not a secret.

You can't have it both ways. Stop sitting on the fence. Make your mind up, and stay with it!

:-)
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Marsu42

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Re: the future of 1.2 L lenses ?
« Reply #42 on: September 20, 2013, 08:50:28 AM »
No, you're not getting away with that, Neuro!

I do sympathize imagining his conflict, I really do - being a Canon gear collector and brand loyalist means one should be inclined to be understanding of Canon's policy, at least up to some point that might change over time or between forum posts :-p

Btw where's the documentation what Canon is doing with iso & the f1.2 lenses?

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Re: the future of 1.2 L lenses ?
« Reply #42 on: September 20, 2013, 08:50:28 AM »

neuroanatomist

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Re: the future of 1.2 L lenses ?
« Reply #43 on: September 20, 2013, 09:54:55 AM »
Doesn't matter, since Nikon doesn't build f1.2 lenses for their system Canon will keep them coming :-p ... no matter if f1.2 with current sensors is really necessary or how many people actually are able to focus them wide open.

...or how much Canon has to secretly push the ISO to compensate for light lost due to the extreme oblique angle of light from an f/1.2 lens, especially since higher sensor pixel density means more push is needed.
No, you're not getting away with that, Neuro!

In an earlier thread, you objected to my saying something like "secretly" about this issue, by retorting that it is explained in some documentation somewhere (I forget the link), and is therefore not a secret.

You can't have it both ways. Stop sitting on the fence. Make your mind up, and stay with it!

You mean this thread?  I wasn't objecting to you calling it sneaky, it is - Canon, Nikon and Sony certainly don't publicize it. But Canon doing it secretly doesn't mean it's really a secret.  My point (objection, if you like) in that thread was the lack of novelty - someone observed the phenomenon on one thread, you replicated it, but it wasn't news - DxOMark had previously quantified the effect (on multiple brands) and published the data.  Next up on new discoveries - when you focus your lens on a close subject, you're getting a shorter focal length than printed on the barrel.  We can run out and do a bunch of tests to confirm that......but it might be easier to just Google "focus breathing".   ;)

Marsu42, the DxOMark data are here.
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Marsu42

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Re: the future of 1.2 L lenses ?
« Reply #44 on: September 20, 2013, 10:03:58 AM »
Marsu42, the DxOMark data are here.

Thanks a lot, that's really interesting...

... 1/2 stop isn't that much so fast lenses are still a valid design vs. f2.8, but this might be part of the answer why Canon recently uses IS primes instead of f1.4 - I doubt a lot of people know about this issue.

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Re: the future of 1.2 L lenses ?
« Reply #44 on: September 20, 2013, 10:03:58 AM »