Tokina lens issue

jgoetz4

Morning Folks,
A few weeks ago, I purchased a used, but new looking, Tokina 80-400mm lens for my 40D. I took a few shots and looked at them full size. After 250mm or so, the images were quite soft no matter what aperture I used. I sent the lens to Bernie over at Pho-Tec Service Center explaining the problem to him. He responded in a couple days and sent me a few pics taken btwn 300 & 400mm, indicating he could not see any issues with the lens. He said he used an Xt to shoot with. I asked him to mount it on a 40D and send me a few of those pictures. Now, I have never had any problems with any of my lenses, either Canon or 3rd party. Has anyone experienced this issue before with a 3rd party lens on a 40D ?
Have a good day
Jim...

ziggy53

We really need some examples with links to full sized images and full EXIF.

That lens can surely benefit from a tripod and there are some who feel that the tripod collar is too small to be totally useful. One user recommends the use of a Manfrotto Telephoto Lens Support, #293.

That lens is also noted for some CA which you would need to correct on post for best results.

So give us some links to images and we might be able to help out.

jgoetz4

ziggy53 wrote:

We really need some examples with links to full sized images and full EXIF.

That lens can surely benefit from a tripod and there are some who feel that the tripod collar is too small to be totally useful. One user recommends the use of a Manfrotto Telephoto Lens Support, #293.

That lens is also noted for some CA which you would need to correct on post for best results.

So give us some links to images and we might be able to help out.

Morning Ziggy and thanks for getting back to me
I'm at work now and do not have any of the Tokina pictures on my work laptop. I have to see If I still have them on my other computer, since I was disgusted with the results. I'll get back to you later this evening. Thanks again and have a good day
Jim...

Tee Why

Looking at the image and the EXIF would help, but IIRC, that lens I hear is fairly soft past 300mm.

It could also be a focusing issue as well.

jgoetz4

Afternoon Folks,
Sorry it's taken me a while to get back, but I have been extremely busy
Anyway, I just spoke with Bernie of Pho-Tech regarding my Tokina 80-400mm lens issue. Apparently, nothing was loose, misaligned or soft and the pictures he originally sent me, proved that. The original Digital Rebel was used in the testing. He did mention that it was possible that the 40D may have a focus issue on some 3rd party lenses. I was curious if anyone else has heard of this possible issue. As soon as I get it back, I'll try it again. Thanks for all the responses
Have a good afternoon folks
Jim...

jgoetz4

Good Evening Folks,
Not sure what to think now that I have taken a few test pictures using live preview. The following crops are bwtn 300 & 400mm, at F9. NO pp was done. The same pictures were taken using AF, but were not as sharp. The EXIF data is included as well. Perhaps the 40D does have an AF problem ??? Let me know what you think please
Have a good evening
Jim...

jgoetz4

#2

jgoetz4

#3

jgoetz4

and finally #4...

Tee Why

To me they just looks soft. The phone photos show a lot of CA as well.

ziggy53

2 of these images are of a telephone pad at close range. What is the Minimum Focus Distance (MFD) for this lens, at what focal length and what was your distance from the object?

I always do critical focus tests from twice MFD. Lenses rarely do their best at close to MFD. It's just a fact of life.

The moon is a classic difficult object to focus against. If you used Live View to focus and took about 6 exposures refocussing each time and showed us the best of the series that would be a fairer test. The moon also generally requires a good tripod and mirror lockup for best results.

The boat shot does look a bit out of focus. Please do use both the XT and the 40D for some side-by-side comparisons to see if one camera does consistently better than the other. That may tell the tale. The boat shot is probably a typical use for this type of lens and you used an appropriate ISO, aperture and shutter speed. If similar images are consistently soft then there may be a problem.

This is a long focal length tele-zoom. Try to pick subjects that would be a normal use of the lens. The moon is a legitimate target but, like I say, notoriously difficult for getting good focus. I like to use traffic signs at a distance for long focal length testing. Use central focus dot only and position the focus target dead center.

Use a higher ISO and short shutter duration during these tests. I suggest shutter speeds of 1/800th to 1/1000th or better for these tests. At f9 this could mean fairly bright sunlight and ISO 400 or so.

jgoetz4

Tee Why wrote:

To me they just looks soft. The phone photos show a lot of CA as well.

Good Morning & thanks for your response
I know about the CA, unfortunately :cry. These are straight from the camera, cropped only, with no pp. They are sharper then the same pictures taken using the AF. I was hoping to hear from someone who had a similiar experience with a 3rd party lens. Thanks again.
Have a good day
Jim...

jgoetz4

ziggy53 wrote:

2 of these images are of a telephone pad at close range. What is the Minimum Focus Distance (MFD) for this lens, at what focal length and what was your distance from the object?

I always do critical focus tests from twice MFD. Lenses rarely do their best at close to MFD. It's just a fact of life.

The moon is a classic difficult object to focus against. If you used Live View to focus and took about 6 exposures refocussing each time and showed us the best of the series that would be a fairer test. The moon also generally requires a good tripod and mirror lockup for best results.

The boat shot does look a bit out of focus. Please do use both the XT and the 40D for some side-by-side comparisons to see if one camera does consistently better than the other. That may tell the tale. The boat shot is probably a typical use for this type of lens and you used an appropriate ISO, aperture and shutter speed. If similar images are consistently soft then there may be a problem.

This is a long focal length tele-zoom. Try to pick subjects that would be a normal use of the lens. The moon is a legitimate target but, like I say, notoriously difficult for getting good focus. I like to use traffic signs at a distance for long focal length testing. Use central focus dot only and position the focus target dead center.

Use a higher ISO and short shutter duration during these tests. I suggest shutter speeds of 1/800th to 1/1000th or better for these tests. At f9 this could mean fairly bright sunlight and iso 400 or so.

Morning Ziggy & thanks for getting back
The MFD of the lens is about 6'. The phone shots were at 300 & 400mm, f9 and were about 25' away.
I did shoot about a dozen shots of the moon, 4 using live view, 4 using MF & 4 using AF. This was the avg out of the live view/MF shots.
The boat shot was handheld, not using live view (my bad). That was around 310mm, f11, iso 500
I did take a shot of a stone column, 225mm, f8, iso 400, and that was clearly sharp using MF. AF was soft, however.
Thanks again.
Have a good day
Jim...

Tee Why

jgoetz4 wrote:

Good Morning & thanks for your response
I know about the CA, unfortunately :cry. These are straight from the camera, cropped only, with no pp. They are sharper then the same pictures taken using the AF. I was hoping to hear from someone who had a similiar experience with a 3rd party lens. Thanks again.
Have a good day
Jim...

I've owned two new tokes, the 100mm macro and a 11-16mm f2.8 (actually two different ones). Both of the 11-16mm models back focus at MFD by 2cm so if you shot a subject at 45degree angle, you can see that the area just behind the focus point was actually in focus. You can try that but in all honesty, from another person that had the same lens and from a review (I can't recall where though) I hear that lens is pretty soft past 300mm.

My buddy sold it eventually b/c he would only use it upto 300mm due to softness and he already had a 70-200mm f2.8 with a TC, which gave better optics, so it made no sensor for him to keep it.

However, if you do find that it consistently misfocuses in AF and you need to correct it in MF, then yes, the AF is off. You can send it into Tokina in Huntington Beach, CA for calibration. If it's not in warranty, I'd think you would have to pay for that though.

jgoetz4

Tee Why wrote:

I've owned two new tokes, the 100mm macro and a 11-16mm f2.8 (actually two different ones). Both of the 11-16mm models back focus at MFD by 2cm so if you shot a subject at 45degree angle, you can see that the area just behind the focus point was actually in focus. You can try that but in all honesty, from another person that had the same lens and from a review (I can't recall where though) I hear that lens is pretty soft past 300mm.

My buddy sold it eventually b/c he would only use it upto 300mm due to softness and he already had a 70-200mm f2.8 with a TC, which gave better optics, so it made no sensor for him to keep it.

However, if you do find that it consistently misfocuses in AF and you need to correct it in MF, then yes, the AF is off. You can send it into Tokina in Huntington Beach, CA for calibration. If it's not in warranty, I'd think you would have to pay for that though.

Good Afternoon & thanks for your response
The area that I focused on is sharper then the surrounding areas, so I do not believe back or front focus is an issue. The pics that Bernie sent from Pho-Tech Service Center were quite sharp (crops) at 350mm. However, he used the original Rebel, which is only 6MP. He also tested the lens for soft or misaligned elements, and everything was satisfactory.
I have included the moon shot, somewhat enhanced (at 400mm,f9) so the lens is definitely useable. Thanks again for your help.
Have a good afternoon
Jim...

Tee Why

I'd like to see his shot and see. If it's sharper on his rebel, then it may be a focusing issue. Plus are these 100% crops?

I'd also recommend downloading a focus sheet and trying out the AF on it.
Here is a link.
http://www.bobatkins.com/photography/technical/focus_testing.html

jgoetz4

Tee Why wrote:

I'd like to see his shot and see. If it's sharper on his rebel, then it may be a focusing issue. Plus are these 100% crops?

I'd also recommend downloading a focus sheet and trying out the AF on it.
Here is a link.
http://www.bobatkins.com/photography/technical/focus_testing.html

Good Evening,
Thank you for your response & the link. Very helpful
I have taken a couple more shots at 300mm, f10, iso 1250, handheld. The following pics are center crops, sharpened slightly. The air conditioner
picture definitely has artifacts, not the result of oversharpening. That picture was about 350' away. The pic of Ginger, my test dog was taken about 50' away. They are definitely usable, once edited, but nowhere near 'L' quality. Still working on 400mm shots.
Thanks to all who responded so far
Have a good evening folks
Jim...

jgoetz4

Meet Ginger, the photo test dog