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Honored Contributor
Posts: 5,436
Registered: ‎08-13-2015

Re: Canon EF 70mm-200mm is ll USM Lens

"You know this is impossible?   DOF is a constant.  It matters not what lens it is if the focal length, aperture and distance from subject is the same DOF is the same." 

 

That is what I would have expected.  Maybe my distance guess-stimates are way off.   Maybe it is my imagination, but I have one lens with a MFD of 14 inches, and another with an MFD of 40 inches.  If I zoom both of them to 50mm, focus on something that is about 8-10 feet away, the lens with the MFD seems to have more stuff in focus.  I've assumed it was a difference in DoF.  Okay, I'm imagining things.

 

Oh, yeah.  I use the lens correction settings in Lightroom for every lens I own, except for one, a Rokinon 85mm T1.5 cinema lens, which has no profile.  That's supposed to be one of my winter projects, creating a profile for it.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
VIP
Posts: 8,118
Registered: ‎12-07-2012

Re: Canon EF 70mm-200mm is ll USM Lens

"That's supposed to be one of my winter projects, creating a profile for it."

 

Go fo it !  But you better hurry as winter is almost gone.

A lot of Canon stuff. Along with, a lot of other stuff.
Honored Contributor
Posts: 5,436
Registered: ‎08-13-2015

Re: Canon EF 70mm-200mm is ll USM Lens

[ Edited ]

ebiggs1 wrote:

"That's supposed to be one of my winter projects, creating a profile for it."

 

Go fo it !  But you better hurry as winter is almost gone.


Yeah, right.  It is supposed to be a teachable moment, but so far I need round tuit.  The Rokinon 85mm T1.5 is a pretty good lens, provided that you have the skills to manual focus.  I have to use LiveView. 

 

The lens has a curious behavior, though, which actually fit the physics of light refraction through a lens.  When you under forcus, short of the subject, you will see Chromatic Distortion in the form of green fringing.  When you over focus, behind the subject, you will see CD in the form of purple fringing.

 

But, when you nail the focus, there is no seemingly chromatic distortion to speak of, not even in bokeh.  All of which presents a curious problem [Yes, I know I think too much. guitly as charged.] when I create a lens profile.  What to do about chromatic distortion, but assume that the focus has been nailed to the wall.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
VIP
Posts: 8,118
Registered: ‎12-07-2012

Re: Canon EF 70mm-200mm is ll USM Lens

I did not know that was even possible.  The focus point should not change the lens characteristics.  Aperture is usually the big factor for CA.

 

But a bigger question?  Why did you go for that highly contested lens for quality control over the Canon 85mm f1.8?  The Canon is a very good lens.  It is one of the best Canon makes.  Besides it works with all its modern features.

 

I can almost understand some body buying the Rokinon 14mm or 24mm. But the guys that did always have to get three or four before they finally get a good copy.  I am surprised BH and Adorama sell them.  I, mysel, have come close to ording the 14mm but I just can't pull the trigger.

 

Dump that Roko and get the ef 85mm f1.8 and move on.

A lot of Canon stuff. Along with, a lot of other stuff.
Honored Contributor
Posts: 5,436
Registered: ‎08-13-2015

Re: Canon EF 70mm-200mm is ll USM Lens

"I did not know that was even possible.  The focus point should not change the lens characteristics.  Aperture is usually the big factor for CA." 

 

I have always thought that the aperture had little or nothing to do with CA, since CA is created, and corrected, solely by the lens elements.  To me, the out-of-focus fringing behavior makes a lot of sense.  Different light frequencies refract at different angles.  Think of how a prism works.

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
VIP
Posts: 8,118
Registered: ‎12-07-2012

Re: Canon EF 70mm-200mm is ll USM Lens

[ Edited ]

CA is when light of different colors is bent differently, resulting in complementary colors on edges. All lenses have a "sweet spot" where they work best.  Most consumer-grade lenses suffer from this axial CA. Most lenses exhibit this to a degree when wide-open or more open apertures.

But, hold on, there are two types of CA.  The other type is sagittal CA.  This type of CA is usually unaffected by aperture.  It is more of a glow or ghostly and the effects are worse in WA lenses.  It usually isn't an issue in teles. But I am sure it can be found in cheap lenses.

A lot of Canon stuff. Along with, a lot of other stuff.
VIP
Posts: 8,118
Registered: ‎12-07-2012

Re: Canon EF 70mm-200mm is ll USM Lens

Zoom lenses tend to have more CA.  Because it is difficult to get everything focused at every focal length.  CA will cause a lens to look more fuzzy or less sharp.  The CA can disappear because of this.  It will be more ugly on sharp edges like tree branches.

Even in a prime lens fuzzyness can make CA not, or less, noticeable.

A lot of Canon stuff. Along with, a lot of other stuff.
Honored Contributor
Posts: 5,436
Registered: ‎08-13-2015

Re: Canon EF 70mm-200mm is ll USM Lens

"But a bigger question?  Why did you go for that highly contested lens for quality control over the Canon 85mm f1.8?  The Canon is a very good lens.  It is one of the best Canon makes.  Besides it works with all its modern features."

 

Ah!  You're thinking stills.  I purchased it for a couple of reasons, primarily for video use.  I got it mainly for the "declicked" aperture feature, so that I can use a follow focus gear on it.  I also got it for the "T" rating scale, instead of f-stop values.  I don't think you can easily change the aperture while filming with the Canon Auto-Focus lenses. 

 

Some of the DSLRs can auto-focus while doing video, which is only useful if you have moving subjects and you do not plan out your shots.  If you're simply "shooting from the hip", like at your backyard barbecue, then having the AF in video mode is very useful.

 

I also bought it because I had already purchased the Rokinon 14mm T3.1, and had been pleased with it. I have used it to take a couple shots of the night skies, but I am too close to city lights to get really detailed shots.  I can get great landscape shots from it, too.  I like the manual focusing because it makes me put more thought into the shot.

 

I don't think you would like the Rokinon 14mm on a full-frame body.  You must really level the lens carefully, or you will get noticeable barrel distortion, even after lens correction in LR6..  However, it gives great images on an APS-C sensor, because most of the barrel distortion is cropped out.

 

Besides, I take a lot of shots from a tripod, anyway, and wind up turning off the AF after I get focus locked.  I can manually focus on what I want better and faster than coaxing the AF system to focus on what I want.  Even with the EF 70-200mm f/2.8L IS II USM lens, which has REALLY good image quality and AF system, I can pull just a little bit more out of it.

 

I use both lenses strictly on a tripod, so that I can use LiveView to focus.  Boy, do I miss the focusing aids in the viewfinders from the old days.  Just line up the edges, and your shot was focused.  I understand that they have focusing screens that do that, but the company has just gone out of business.  I bought both Rokinons on sale, at just over the combined cost of the EF-85mm f/1.8 lens list price.

 

Tonight, I will try to setup sample shots of the green fringing from under focusing, purple fringing from over focusing, and no fringing when you nail the focus.  I posted a review of the Rokinon 85mm at my favorite NYC superstore, with some sample images.

 

 

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"I don't rent software. I use Photoshop CS6, ACR 9.8 and Lightroom 6.8 ."
VIP
Posts: 8,118
Registered: ‎12-07-2012

Re: Canon EF 70mm-200mm is ll USM Lens

[ Edited ]

If you are just concerned and shooting video, there is little to no info I can offer.  So it will be a waste of time.  I don't shoot video and I very rarely use Live View.

 

I have friends that have eventually got a decent Rokinon lens.  I am not that patient so at this point I probably will pass.  But I do know from seeing one in action, they can be quite good.  Apparently yours is one of the many bad ones. There are too many good brands out there to play with so avoiding Rokinon isn't a big deal.

 

I will bow out from the video stuff as I have no experience or interest in it.

A lot of Canon stuff. Along with, a lot of other stuff.
New Contributor
Posts: 4
Registered: ‎10-17-2017

Re: Canon EF 70mm-200mm is ll USM Lens

My hubby surprised me with a new lens of my choice 

This lens will shoot indoor high school wrestling.

I also shoot stock too, but only a handful of hours per year.

I thought for sure I would want the Canon 70-200mm IS 2.8 II and considered the Canon 70-200mm IS 2.8 I but Canon is no longer serviceing them.

But I am having doubts that maybe the Canon 70-200mm IS 4.0 would be just as good and it's half the weight! (Not to mention cheaper) 

I shoot with a Canon EOS 5D MkIII, no flash, and it seems I can just ramp up the ISO with the 4.0 to equal the light of a 2.8. Am I correct for thinking this?
I know the DOF is nicer with the 2.8 but think I would carry the lens more if it was lighter in weight. 

I have been researching my shots from years past and looked at the specs of the 8 indoor environments I shot last season.

The majority of the shots were as follows:
6400 - 4.0 - 1/500 - 70mm
5000 - 2.8 - 1/800 - 70mm
5000 - 2.8 - 1/640 - 70mm
10,000 - 2.8 - 1/400 - 70mm
10,000 - 2.8 - 1/640 - 70mm
8,000 - 4.5 - 1/640 - 70mm
2,500 - 2.8 - 1/400 - 70mm
10,000 - 2.8 - 1/800 - 70mm

Do you see any wiggle room to make a 70-200mm 4.0 work? 
10,000 ISO at 2.8 is pretty high don't you think?
I do have access to the local gym on Tuesday evenings I can practice with the only lens I have, a Canon 24-70mm.

Also, the majority of the shots were at 70mm, then...
If I shoot at 200mm, is the light constricted even more; the higher the mm, the more you have to add/accommodate your lens with light?

Please help me make my decision before the season comes in a few weeks.

Thank you for your help 

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