rthompson10

All,

To continue my saga of new"(used) full frame and using my Canon 70-2002.8 Vii for shooting sports over the last couple of weekends I've rented a Canon 1.4VII converter from the local camera store. Shooting yesterday in daylight(cloudy) my hit rate as far as shots in focus was very low- Camera would give me AF in viewfinder but a good percentage of shots not clear. Using a focus point plugin on a couple of shots in LR shows a locked focus point but pictures are blurry- Any thoughts- pictures ranged from subjects coming at me at an angle to subjects moving across screen. Had much better results last weekend- not sure if specific converter was different and this weeks was "off"?

RT

CHG_CANON Loc: the Windy City

Best way to diagnose is for you to attach some SOOC JPEGs and store the original. Or, convert from RAW via LR with no adjusts over than JPEG conversion. Given an EOS body, a JPEG straight out of camera (SOOC) is better as we can see Canon-specific details via DPP.

The VIII extenders have the same optics as the VII, but "better" electronics that will improve the AF performance. If not already doing so, you should be using AI Servo. You also should have a shutterspeed fast enough to freeze action. All these potential issues / opportunities can be assessed from actual images where the original is stored.

rthompson10

Imported in lightroom already- see if this has the info

CHG_CANON Loc: the Windy City

You have to store the original ....

Additionally, LR does not modify the original file. If you shot in JPEG, just right-click the image in the LR grid view and select "show in explorer". Then, attach and store that file.

Grahame Loc: Fiji

It appears in this shot that the guy centre and the guy far left (sharp) are basically on the same focus plane, suggesting 'movement' may be your problem with this example.

I suggest you undertake testing with a static subject using a tripod to assess results, which may also show any possible front or rear focus issues with the TC attached.

rthompson10

Pic with data attached

(Download)

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Movement is not the issue at 1/4000 sec. The guy at the left is less soft than the others, but nothing in the frame is in focus at all. The grass is a big clue. One the left it is less soft, and it gets really soft at the right. Almost looks like you used a LensBaby with a strong tilt. If the lens seems fine without the TC, then it seems like, just taking a big guess here, the TC is broken, perhaps a decentered element resulting from an impact. That combination is usually excellent.

Grahame Loc: Fiji

Now we can see the Exif that eliminates that possibility, time for some static testing.

I have a Nikon setup and with my TC 1.4 on both a 70-200 and 80-400 it requires max fine tune adjustment but even without it you could easily see by the grass where the focus was but there's a massive difference between left and right sides here.

User ID

`

Best focus, almost in-focus, is in the
far corner lower left, which should be
exactly the same focus as the lower
right far corner which is total mush.
Therefor it's NOT a focus error.

Either the TC has a physical problem,
or you "roll" the camera when using
the shutter release, and the axis of
that movement passes thru the lower
right corner of the picture which is
the upper right corner of the sensor.

That is quite possible. The grass in
lower left is in focus but not sharp
while the further your get from the
roll axis the greater the movement.
Your right hand grip on the shutter
button side of the body would be
much more stable than your left
hand grip that supports that long
heavy optical combination. BUT! I
see no evidence of camera roll in
the upper right corner of the pic,
and despite the lack of focus in
that area, the bright while lines
are highlights which create clean
contrast edges ... horizontal and
vertical ... that would have been
streaked by camera movement.
So I tend to agree with physical
problems in the TC.

I would expect many, or all, of
your other frames to show a very
similar effect, a further indication
of a faulty TC rather than camera
roll or any other user error.


`

Architect1776 Loc: In my mind

Use the III version instead.
It is matched to the VII of your lens.
Should easily solve any equipment problems and from there it becomes user error.

Jolly Roger Loc: Dorset. UK

Robert, whilst there did you also shoot any without the T/C ? If so what did they look like ? If you did, post a shot here using the "Store original" check box.
Looking at your posted image nothing is in focus. Bottom left grass is the closest but bottom right grass is way off. Using a shutter speed of 1/4,000 sec should negate camera movement when depressing the shutter button.
It looks to me as though something is out of alignment, probably the rented T/C. Hence my question about a shot without using it.

agillot

looking at the picture , the more you look to the right the worst it get , if you go to the left , by the time you get there , the pic look in focus .almost like a miss alignment of the lens .would have liked to see same pic without the TC .

imagemeister Loc: mid east Florida

It sounds very much like a TC/defective issue. Maximum AF performance with that lens will be seen with the ver III TC - however, the ver II should be working very GOOD !

Have you done a focus calibration WITH the TC attached ??

..

dsmeltz Loc: Philadelphia

What are you focus settings? Are you using BBF as well?

rthompson10

All, thanks for the responses
Nope didn't use lens without TC so nothing to compare to
Lens plus TC mounting looked a little off- like it wasn't seated properly- so if you looked down the barrel of the lens from overhead had a slight angle to it. Guy in camera store I rented it from mounted it and said looked ok and would work ok
Rented this same TC(same rental ID) last weekend- everything was fine
Using BBF- focus notification in viewfinder came on
RT