Luminous Landscape Forum

Equipment & Techniques => Cameras, Lenses and Shooting gear => Topic started by: davekx on February 02, 2011, 08:45:38 am

Title: Nikon 24 PCE
Post by: davekx on February 02, 2011, 08:45:38 am
What is involved and the cost to have the Nikon 24 tilt shift lens modified to have the two axis move independently does it void the warranty on the lens?
Is this lens regarded as highly as the Canon 24 TSE II?
When will the recently announced Schneider R tilt shift lenses be released?

Thanks....Dave



Title: Re: Nikon 24 PCE
Post by: PeterAit on February 02, 2011, 11:13:32 am
The change is free if done by Nikon during the warranty period. Be sure to send a copy of your receipt with the lens-I neglected to and got caught in some bureaucratic maze.
Title: Re: Nikon 24 PCE
Post by: langier on February 02, 2011, 03:50:07 pm
IF you are comfortable with a cross-point screw driver, fully sober, have a well-lighted work area and use a tray to catch the stray screws, you can do this yourself in less than 5 minutes.

There are four screws on the back corners of the widest part of the lens. Take all four out and "carefully" rotate 90 degrees (can't really remember which way to rotate, other than the ribbon cable is the key). Once rotated, carefully put the screws back in and tighten with your cross-point.

Of course, your results may vary and you are on your own if you screw-up or loose your screws, but as far as a mod/fix/repair, it's super simple and quick. I'd do it in your studio and never in the field unless I was total desperate to have both a rise and a swing.

For me, I generally use this lens and my 85 PC with the rise-fall and tilt, seldom at the 90-degree factory default.
Title: Re: Nikon 24 PCE
Post by: Kirk Gittings on February 02, 2011, 03:53:33 pm
Quote
Is this lens regarded as highly as the Canon 24 TSE II?

Not quite. I have tested both and the Canon has a slight edge. Besides that the Canon can shift axis' on the fly
Title: Re: Nikon 24 PCE
Post by: langier on February 02, 2011, 10:57:04 pm
Even though Canon may have a slight edge and on-the-fly axis twist, Nikon's 24PCE is still a great lens!
Title: Re: Nikon 24 PCE
Post by: happyman on February 04, 2011, 09:03:29 am
The Nikon lens is way better then the Canon: sharpness, flare, CA
Title: Re: Nikon 24 PCE
Post by: Kirk Gittings on February 04, 2011, 10:35:36 am
The Nikon lens is way better then the Canon: sharpness, flare, CA


Not in the samples I tested. Not against the new Canon.
Title: Re: Nikon 24 PCE
Post by: MrSmith on February 04, 2011, 03:15:38 pm
the Nikon really must be something extra special, seeing as the canon is merely 'special' ::)
Title: Re: Nikon 24 PCE
Post by: Tony Beach on February 05, 2011, 02:29:03 pm
Modifying a PC-E lens costs about $125 at a Nikon Service center.  On the 24/3.5 you can do it yourself because the ribbon in the lens is just long enough to reach 90°, but on the 45/2.8 you will have to send it in to have it done.  As for the warranty, I would presume that if you send the lens in for a warranty covered issue and you modified it yourself, you could just return it to its original position and avoid any issues.  The worse case scenario is that you have to pay for the the ribbon being severed or the screws being stripped, but if it is something else then Nikon should fix it if it is in fact covered by the warranty.

As for the Schneider's, they look like they will spank Nikon and Canon, but the Super Angulon 28/2.8 PC (which has been out for some time now) does not have tilt and the 50mm and 90mm lens are going to be a lot more expensive than the Nikon or Canon options.
Title: Re: Nikon 24 PCE
Post by: JeffKohn on February 05, 2011, 04:26:12 pm
Here's a guide (http://www.motifnation.hu/index.php/type/concept/nikon_pc-e_24mm_tilt_shift_axis_swap/) with step-by-step pictures for modifying the 24 PC-E, it really is quite easy.

Quote
As for the Schneider's, they look like they will spank Nikon and Canon, but the Super Angulon 28/2.8 PC (which has been out for some time now) does not have tilt and the 50mm and 90mm lens are going to be a lot more expensive than the Nikon or Canon options.
The Schneider 28 PC Super-Angulon is a dud optically. I paid full retail for this overpriced lens (special order from B&H) literally weeks before Nikon announced the 24 PC-E and 45 PC-E. Biggest regret of any camera-related purchase I've ever made. So I won't be assuming that the new Schneider lenses spank anything until I see detailed reviews from trusted sources.
Title: Re: Nikon 24 PCE
Post by: Kirk Gittings on February 05, 2011, 05:08:47 pm
Here's a guide (http://www.motifnation.hu/index.php/type/concept/nikon_pc-e_24mm_tilt_shift_axis_swap/) with step-by-step pictures for modifying the 24 PC-E, it really is quite easy.
The Schneider 28 PC Super-Angulon is a dud optically. I paid full retail for this overpriced lens (special order from B&H) literally weeks before Nikon announced the 24 PC-E and 45 PC-E. Biggest regret of any camera-related purchase I've ever made. So I won't be assuming that the new Schneider lenses spank anything until I see detailed reviews from trusted sources.

Yes, I was going to say.......don't assume because It is a Schneider that it is a great lens, they have made PC lenses in the past that were expensive and stunk!
Title: Re: Nikon 24 PCE
Post by: uaiomex on February 05, 2011, 05:36:10 pm
Under current technologies producing substantially better lenses than latest Canon TS's would make them prohibitory. I think they are as good as is possible right now for a commercial success. IMHO.
Eduardo
Title: Re: Nikon 24 PCE
Post by: Tony Beach on February 05, 2011, 08:23:09 pm
The Schneider 28 PC Super-Angulon is a dud optically. I paid full retail for this overpriced lens (special order from B&H) literally weeks before Nikon announced the 24 PC-E and 45 PC-E. Biggest regret of any camera-related purchase I've ever made. So I won't be assuming that the new Schneider lenses spank anything until I see detailed reviews from trusted sources.

You must have gotten a bad copy and I'm sorry that you experienced that; my copy is not a dud and I also owned the Nikkor 24/3.5 PC-E.  On the Nikkor I could find poor corners using extreme shifts on my D300 (which didn't even utilize the entire image circle), whereas on the Schneider the corners hold up better at the edges of the image circle.  The main reason I would say the 50mm and 90mm lenses will spank their Canon and Nikon counterparts (and especially the Nikon ones I regret to say) is that they have a tripod mount on them, the functions can each rotate 360° independently of one another, and if the resolution and micro-contrast I get from my 28mm PC is any indication then the optics will be exceptional.  Another thing I look forward to (but am not certain about yet) is that on my 28 PC I can change mounts and match the lens to my Sony A850, a Nikon F mount, or a Canon EOS mount; I'm hoping this will also be the case for the 50mm and 90mm Schneiders, and that will make them a slam-dunk for me.
Title: Re: Nikon 24 PCE
Post by: tesfoto on February 06, 2011, 04:52:11 am
The Nikon lens is way better then the Canon: sharpness, flare, CA


I tested the lenses and my findings are:

The Nikon was about the same center sharpness as the Canon TS-E (old version) but was way better in the corner sharpness.

The Nikon 24PCE is a very good lens.

Then Canon came out with the TS-E II and this lens is way better in sharpness, flare and CA.

I know of architectural photographers changing system from Nikon to Canon due to the new 17 and 24.

My take is that Nikon (D3X) produces better files than Canon 1DsMKII and 5DII, but the 17 and 24 lenses are game changers for architectural photographers.

Title: Re: Nikon 24 PCE
Post by: Rob C on February 06, 2011, 05:03:18 am
Years ago, when the 28mm Schneider shifter came out, it was reviewed in the BJP and given a very positive rating. Its competition, in my world, was the Nikkor, and according to the reviewer, Nikon didn't quite reach the parts that Schneider could. Schneider also made other great optics for Leica: the 21mm Super Angulon was much rated in its day, too.

This thing about 'bad' copies is something for which manufacturers have only themselves to blame. In my active days I can't remember having even heard of a dud Nikkor; today, I find that even I had the misfortune to buy one such new one - that damn 2.8/24-70mm which I did manage to dispose of back to the shop, but only because I took a new 2.8/180 its place. I have hardly used the latter, despite liking longish lenses, but that's my problem and not Nikon's.

The problem goes beyond one dud lens: once you have had the bad, expensive experience, you distrust everything that comes from that maker. To lose that much goodwill is industrial suicide: how come they don't see this for themselves? Do they bank on other marques' disillusioned people changing over for more of the same, a constant turnover of angry owners drifing from one make to the other in a futile search for something that's honest? The solution/salvation is so simple: proper final inspection of every unit. From my first new F in the 60s to last year's disaster I would have sworn by Nikon; not anymore.

Rob C
Title: Re: Nikon 24 PCE
Post by: kers on February 06, 2011, 06:52:28 am
You must have gotten a bad copy and I'm sorry that you experienced that; my copy is not a dud and I also owned the Nikkor 24/3.5 PC-E.  On the Nikkor I could find poor corners using extreme shifts on my D300 (which didn't even utilize the entire image circle), whereas on the Schneider the corners hold up better at the edges of the image circle.

I am using the 24PCE now for almost a year and it took me a while how to get everything sharp even in the corners when fully shifted.
Now I use this method and it works:  use f9- or fully shifted f11  and check with this lensopening the sharpness with Live-view. I am shure your results will become better...
Title: Re: Nikon 24 PCE
Post by: Tony Beach on February 06, 2011, 11:22:48 am
I wrote:
...I also owned the Nikkor 24/3.5 PC-E.  On the Nikkor I could find poor corners using extreme shifts on my D300 (which didn't even utilize the entire image circle), whereas on the Schneider the corners hold up better at the edges of the image circle.

I am using the 24PCE now for almost a year and it took me a while how to get everything sharp even in the corners when fully shifted.
Now I use this method and it works:  use f9- or fully shifted f11  and check with this lensopening the sharpness with Live-view. I am shure your results will become better...

Sounds like a kludge solution to me.  Are you proposing that I focus on the edges to the detriment of where I might otherwise want my focus to be?  FWIW, I was shooting f/13 at infinity on targets that were at infinity and the level of smearing at the extreme edges of the image circle as recorded on my D300 were really quite bad.  It's possible I got a "dud" copy though, but getting the far edges of such a large image circle is always going to be problematic on such a wide angle lens.

I don't have the 24 PC-E anymore, in part because I use an A850 and that Nikkor will not work on it.  As I said before, if the Schneiders have interchangeable mounts, this will make them hugely appealing to me for that very reason.
Title: Re: Nikon 24 PCE
Post by: Kirk Gittings on February 06, 2011, 03:13:40 pm
I tested the lenses and my findings are:

The Nikon was about the same center sharpness as the Canon TS-E (old version) but was way better in the corner sharpness.

The Nikon 24PCE is a very good lens.

Then Canon came out with the TS-E II and this lens is way better in sharpness, flare and CA.

I know of architectural photographers changing system from Nikon to Canon due to the new 17 and 24.

My take is that Nikon (D3X) produces better files than Canon 1DsMKII and 5DII, but the 17 and 24 lenses are game changers for architectural photographers.



FWIW I have no brand loyalty or silly romantic notions of long term brand superiority. Ultimately they are just slightly better or worse hammers and in two years the leader position will switch. Anyone could do a decent job these days shooting architecture with Canon or Nikon. All the above quoted points reflect my experience, I almost switched to NiKon for the DX3 and PCE lenses, but before I did Canon came out with their new T/S lenses. Ideally I would like the Nikon body and Canon lenses, but probably by next year the Canon bodies will get there too. I personally follow the glass and let the bodies catch up.
Title: Re: Nikon 24 PCE
Post by: Nacnud on February 07, 2011, 06:59:28 am
Sounds like a kludge solution to me.  Are you proposing that I focus on the edges to the detriment of where I might otherwise want my focus to be?
Kers experience matches mine....
I've got both the MkI and MkII Canon 24mm TS-E and often get apparent corner softness when centre focussing.
I also sort it out by increasing DoF and tweaking focus.

I believe the focal plane is spherical, not flat - it's part of the Tilt/Shift design.
Hence when shooting a flat surface (like a building), the corners cannot be sharp unless DoF and focussing take this into account.

Standing by to be shot down in flames - Duncan
Title: Re: Nikon 24 PCE
Post by: adammork on February 07, 2011, 08:56:52 am
I know of architectural photographers changing system from Nikon to Canon due to the new 17 and 24.

My take is that Nikon (D3X) produces better files than Canon 1DsMKII and 5DII, but the 17 and 24 lenses are game changers for architectural photographers.

I'm one of those who changed system.... The D3X have a better file, by a fair margin, but those two new TS-E lenses are just so fantastic! - so are the old 90mm, but the 45mm kind of sucks.

Like Kirk, my dream would be the D3X body with the Canon TS-E's and the Canon way of live view (and Olympus's anti dust system, for making the dream complete....)

/adam

Title: Re: Nikon 24 PCE
Post by: Bart_van_der_Wolf on February 07, 2011, 09:35:25 am
I believe the focal plane is spherical, not flat - it's part of the Tilt/Shift design.
Hence when shooting a flat surface (like a building), the corners cannot be sharp unless DoF and focussing take this into account.

There is no need to believe, when you can make sure. All it takes is a simple (yet critically sensitive) test. Just shoot a detailed floor/street surface, from a shallow/low angle without tilt, at a wide aperture. When the focal plane is not planar, then the DOF area will not be a straight line. You can test it with the focus in the center of the lens, and with the focus at e.g. the lower edge. You can even add left/right shift.

Make sure that you don't confuse a tilted plane of focus with a curved plane of focus!

That should convert you from a believer into someone in the know, whatever the outcome.

Cheers,
Bart
Title: Re: Nikon 24 PCE
Post by: Tony Beach on February 07, 2011, 11:37:48 am
Kers experience matches mine....
I've got both the MkI and MkII Canon 24mm TS-E and often get apparent corner softness when centre focussing.
I also sort it out by increasing DoF and tweaking focus.

I believe the focal plane is spherical, not flat - it's part of the Tilt/Shift design.
Hence when shooting a flat surface (like a building), the corners cannot be sharp unless DoF and focussing take this into account.

First, I'm referring to my experience with the Nikkor 24 PC-E and with the Schneider 28 PC, so how that relates to a Canon T/S lens is murky at best.  Second, my Schneider does better than what I got from my Nikkor.  Third, the issue only arose at the extreme edges of the image circle, neither lens I had experience with required any kludging of the focus when not shifted.  Fourth, my experiences involved using the lenses focused at infinity with what should be infinite DOF (subjects at 20 or more feet away shot at f/13).
Title: Re: Nikon 24 PCE
Post by: Nacnud on February 07, 2011, 11:51:03 am
LOL - both of you have made good points :)

Kers experiences are sufficiently similar to mine that I believe there may be parallels in the design of the two lenses.

I can't do the testing right now, but I did have enough time to do some Googling....
I found a relevant article right here on LL (http://www.luminous-landscape.com/tutorials/focusing-ts.shtml)
The last section is the relevant bit.
"I have read in many reviews from owners of these lenses complaining about the edges not being sharp at wide apertures. This is true and although not desirable it is necessary and can be quite simply explained. This lens is not of a flat field design!"

That's quite a heavy article and certainly reinforces that not all T/S lenses are going to have the same focussing characteristics.
Really interesting thread this one; I'm looking forward to seeing where it heads.
Duncan
Title: Re: Nikon 24 PCE
Post by: kers on February 07, 2011, 01:40:19 pm
I'm one of those who changed system.... The D3X have a better file, by a fair margin, but those two new TS-E lenses are just so fantastic! - so are the old 90mm, but the 45mm kind of sucks.
Like Kirk, my dream would be the D3X body with the Canon TS-E's and the Canon way of live view (and Olympus's anti dust system, for making the dream complete....)
/adam


I stay with Nikon for the moment...
The 45mm PCE is a great lens as is the 85mm PCE.  from 2,8 on very good
Then there is the fantastic 14-24mm...
the new non zoom pro-lenses are all very expensive but very good...
Then there is the D3s for all my bad lit subjects...
Title: Re: Nikon 24 PCE
Post by: Rob C on February 07, 2011, 01:53:04 pm
Kers experience matches mine....
I've got both the MkI and MkII Canon 24mm TS-E and often get apparent corner softness when centre focussing.
I also sort it out by increasing DoF and tweaking focus.

I believe the focal plane is spherical, not flat - it's part of the Tilt/Shift design.Hence when shooting a flat surface (like a building), the corners cannot be sharp unless DoF and focussing take this into account.

Standing by to be shot down in flames - Duncan


Duncan

Not eclusive to T/S lenes: the BJP did tests on wide lenses during the late 80s - early 90s and they did this by setting up a camera (I think it was 4x5) and actually putting a series of markers down on the ground in an open square somewhere, in whichever position that they appeared the sharpest on the screen. On completion, it turned out that the marker cones described a curve, leading to the conclusion that the plane of sharpness wasn't really a flat plane at all, but a shell-like thing....

So no flames this time!

Rob C
Title: Re: Nikon 24 PCE
Post by: messengerphoto on February 10, 2011, 10:00:31 pm
You seem to be very well versed in the use of the T/S lenses. I own Nikon. I wanted to buy the PCE-24 but after reading your comments, as well as a lot of other Architects comments, I am now certain the Canon T/S 24mm is a better lens. I wish to keep my Nikon gear.  Is it worth it, in your opinion, to buy the Canon T/S 24mm lens, and a cheaper Canon body? I was thinking of getting either a used D40, or D20, or even a newer Rebel body, say the T2i?  This allows me to buy the better Canon Glass, but still keep what I like in the Nikon. Thanks for your input.
John Messenger
 ???
Title: Re: Nikon 24 PCE
Post by: pfigen on February 11, 2011, 01:42:58 am
"Is it worth it, in your opinion, to buy the Canon T/S 24mm lens, and a cheaper Canon body? I was thinking of getting either a used D40, or D20, or even a newer Rebel body, say the T2i?"

You would probably want to get a full frame body with LiveView focusing in order to get the most from this great lens. That means a 5D2.

I also have to say that while I haven't done really formal tests, both the 17 and 24 t/s Canons seem to have a much flatter field of focus than any other wide angles I've used for 35mm based cameras.
Title: Re: Nikon 24 PCE
Post by: messengerphoto on February 11, 2011, 08:20:15 am
I was afraid of that. I don't mind having another system, but I certainly mind the price.
Thanks for your reply.
Title: Re: Nikon 24 PCE
Post by: Nacnud on February 11, 2011, 12:16:49 pm
I think sensor size is not critical as the edges and corners are always the optical weakpoints and they get cropped off APS-C images. It's more question of whether you need a true 24mm or the 38mm equivalent APS-C ends up with.

Live view is seriously desirable for tweaking focus!
Good manual control is essential because the metering goes loopy when shifting.
High ISO isn't an issue because it'll be on a tripod most of the time.
I guess RAW is not essential because you can bracket your exposures.

If you don't want to buy new, then I'd suggest a 40D which is one of Canon's benchmark models and a good all-round performer.
However, if you are thinking of buying Canon because of the TS-E lens quality then maybe you need to think about investing in a body that will do the lens justice.
Title: Re: Nikon 24 PCE
Post by: pfigen on February 11, 2011, 12:50:20 pm
Nacnud - Almost everyone I've ever run in to who buys a 24mm T/S lens is buying one for the 24mm full frame angle of view, so I would suggest that sensor does make a difference. Nothing wrong with a 38mm equivalent, but it's not a very practical focal length for the types of images that these lenses are commonly used for. And there are 35mm shift lenses available as well (I own both the Oly and the Zeiss).

As far as the new lenses not being sharp it the corners of a full frame sensor image, that's completely bogus. The Canon 24 II is sharp even wide open into the unshifted corners. It's arguably the sharpest 24mm lens available for any 35mm platform.

Here's the real deal on shifting: Most of the time when shooting buildings, interiors, products, portraits, etc. your shifting is going to be up and down if you're using a horizontal frame, and while there is some falloff in resolution at the extreme horizontal shift on a horizontal frame, there is none visible when shifting up or down. That's not to say you can't shift laterally, you do want to watch the extreme corners though. Is that enough to keep you using a crop sensor? Hell, no. In fact, one of my favorite ways to use these lenses, the 17 t/s in particular, is to shoot three horizontal images that are stitched into a single file that is the equivalent of the 36 x 48 mm frame. Those images, if focused carefully are sharp all the way to the corners, and make for something close to what a 10 or 11 mm lens would see on a full frame, except you've now got the equivalent area of a MFDB. Pretty amazing and even wider than a Rodenstock 23 on an Alpa.

Just to emphasize the point, I'll post an image that illustrates this. These lenses, as I've said before, have changed what's possible. This was actually a handheld image, stitched from three frames - shifted up, down and normal, with the Canon 17. It's the new wing of the Kaiser Hospital in W. L.A. and using a tripod would have brought in the security guards, but you get the idea
Title: Re: Nikon 24 PCE
Post by: Nacnud on February 11, 2011, 02:31:25 pm
Yeah - I'm full frame myself; but the post did mention not wanting to spend huge money on the body.
If 38mm is OK for what they want to do, then it's an affordable way to start making use of the lens with the option to upgrade the body later.
Used 40D's seem to be holding their value, so they wouldn't lose much money.

I know what you mean about 38mm not being convenient.
I also do festival photography and used to do a lot of stitching to get the images wide enough with the 24-105. Then I got the 5DII and I now find I rarely stitch...

I'm out with the TS-E tomorrow - I'll take a critical look at how I'm focussing and will report back.
Yes it's sharp - it's the first lens I've used that's noticeably sharper than my 70-200 f4 IS L.
It's jaw droppingly sharp.
But I'm sure I found and corrected the symptoms I've described during an intensive landscape shoot last month.


That's an incredible shot you posted; especially considering it is a hand-held shifted stitch. I've always used a tripod for mine!
Title: Re: Nikon 24 PCE
Post by: messengerphoto on February 12, 2011, 11:40:41 am
Thanks for all the information. I am going to reconsider my budget. I am convinced the lens will provide optimum benefit when coupled with a full frame camera, regardless of the manufacturer. I may have to compromise and purchase the Nikon version, knowing it is not quite the same as the Canon. Dykinga (sp) produces fantastic images with the Nikon Pce's. The Nikon D700 should hit the market at a good used price very soon and that should allow me to meet my objectives.  Y'all are a great help.
Title: Re: Nikon 24 PCE
Post by: craigwashburn on February 12, 2011, 04:46:51 pm
Question for nikon 45 T/S owners - do you find your focus slipping when its pointed down?  I did buy mine used from KEH, and it is in excellent condition, but I do find focus slips a hair when the barrel is pointing down. 

Right now a piece of gaff tape is my solution, but if this isn't a common problem it's probably worth sending in for a tightening up.

Title: Re: Nikon 24 PCE
Post by: Tony Beach on February 12, 2011, 05:13:15 pm
I never noticed any creep with my Nikkor 45/2.8 PC-E.
Title: Re: Nikon 24 PCE
Post by: langier on February 14, 2011, 09:01:13 am
On my 24 PC there is a little bit of creep unless you tighten it down, otherwise a great lens for me.

I might add that I usually leave the lock knobs just loose enough so I can make an adjustment without having to tighten them in most cases unless I'm doing a critical series of photos such as in the studio. Sort of like adjusting an Arca-Swiss tension knob so that it stays put when you mount your camera but without too much slop that things go limp and flop-over.
Title: Re: Nikon 24 PCE
Post by: JeffKohn on February 14, 2011, 08:03:35 pm
Question for nikon 45 T/S owners - do you find your focus slipping when its pointed down?  I did buy mine used from KEH, and it is in excellent condition, but I do find focus slips a hair when the barrel is pointing down. 

Right now a piece of gaff tape is my solution, but if this isn't a common problem it's probably worth sending in for a tightening up.
If you're saying that you get some creep even when the tilt/shift knobs are tightened down, then no I have not see that. What I have seen is that with the 45 in particular you need to tighten down those knobs after adjusting tilt/shift, because there is some "slack" when they are loosened that can affect the plane of focus. But I've never seen any slipping of the focus ring itself.
Title: Re: Nikon 24 PCE
Post by: craigwashburn on February 15, 2011, 04:10:26 pm
If you're saying that you get some creep even when the tilt/shift knobs are tightened down, then no I have not see that. What I have seen is that with the 45 in particular you need to tighten down those knobs after adjusting tilt/shift, because there is some "slack" when they are loosened that can affect the plane of focus. But I've never seen any slipping of the focus ring itself.

No creep on the shift or tilt (once locked), it's the actual focus ring that slips a smidge with gravity's pull on front element.  I only notice it when shooting straight down on something at macro distances.  For now I've just placed a piece of gaff tape across that gives it enough friction that it won't slip.  My 24 doesn't have the issue.  At some slow point I'll get it in to NPS for a tightening. 

I just pulled it out to experiment, the barrel rotates all of a millimeter at most.  Though at a few inches distance that is enough to throw critical focus out.