300 f/2.8L and 400 f/2.8 at f/2.8

[bdunbar79]

Yeah a lot of my shots were from a slope or slight increase in gradient. Wonder if at such a wide aperture, if my camera is tilted downward, the focal plane is slanted enough that the face is in line with the grass in front? Oh hell I don't know, I'm shooting with my 300 tomorrow until I know what's going on and thankfully I posted these or I wouldn't have looked until tomorrow night.

That would explain why my track ones don't display this, or unless the misalignment just happened recently.

 

[kaihp]

Quick test: if it's due to a tilted lens element, it should follow the orientation, right?. So shooting the same situation in portrait and landscape should settle whether this is the root cause.

 

[serendipidy]

Let us know how it all works out. And good luck with your shooting tomorrow.

 

[bdunbar79]

Here's one more example of some photos I had on my card, first one is the actual shot, and then I cropped a lower section.

 

[privatebydesign]

Quick test: if it's due to a tilted lens element, it should follow the orientation, right?. So shooting the same situation in portrait and landscape should settle whether this is the root cause.

Yes, that is correct.

No to standing on a slope, that WILL NOT do this.

 

[bdunbar79]

Quick test: if it's due to a tilted lens element, it should follow the orientation, right?. So shooting the same situation in portrait and landscape should settle whether this is the root cause.

Yes, that is correct.

No to standing on a slope, that WILL NOT do this.

I didn't think it would.

 

[bdunbar79]

Well, I'm looking at my lens now, and I took it off the camera. The lens mount was loose, I turned the camera about 45 degrees, it held and clicked, as it turned it to 90 degrees to release it. All four screws on the mount are ready to come out and I'm just wondering if this is because at football and soccer I don't pick it up and put it down so much, but at golf I'm putting it into a cart and taking off all the time.

I do NOT have a tool right now to tighten those screws, as luck would have it. Also not claiming this is the issue.

 

[privatebydesign]

Well, I'm looking at my lens now, and I took it off the camera. The lens mount was loose, I turned the camera about 45 degrees, it held and clicked, as it turned it to 90 degrees to release it. All four screws on the mount are ready to come out and I'm just wondering if this is because at football and soccer I don't pick it up and put it down so much, but at golf I'm putting it into a cart and taking off all the time.

I do NOT have a tool right now to tighten those screws, as luck would have it. Also not claiming this is the issue.

Do not remount the lens until those screws are tightened!!!!!

I had a similar issue with a 70-200 f2.8 IS on a 1D, one of the mount screws came loose and jammed in the body mount recess. They were stuck together and it was only because I was working with a micre electrical engineer and he had some very cool small tools that he was able to separate the pair.

That is almost certainly your de-centering issue too.

 

[bdunbar79]

Well, I'm looking at my lens now, and I took it off the camera. The lens mount was loose, I turned the camera about 45 degrees, it held and clicked, as it turned it to 90 degrees to release it. All four screws on the mount are ready to come out and I'm just wondering if this is because at football and soccer I don't pick it up and put it down so much, but at golf I'm putting it into a cart and taking off all the time.

I do NOT have a tool right now to tighten those screws, as luck would have it. Also not claiming this is the issue.

Do not remount the lens until those screws are tightened!!!!!

I had a similar issue with a 70-200 f2.8 IS on a 1D, one of the mount screws came loose and jammed in the body mount recess. They were stuck together and it was only because I was working with a micre electrical engineer and he had some very cool small tools that he was able to separate the pair.

That is almost certainly your de-centering issue too.

I took off the camera and will just shoot with my 300 f/2.8 tomorrow. When I get a tool to tighten them, and I go ahead and do it, how can you exactly tighten them such that the de-centering issue is gone? Or is it just good enough? My fear is overtightening or undertightening. Thanks.

 

[bdunbar79]

Well if anyone is REALLY bored, and wants to follow this little mini-drama, it's 12:08am here and a friend of mine who has a tool is still awake, so I'm heading over .

 

[privatebydesign]

I took off the camera and will just shoot with my 300 f/2.8 tomorrow. When I get a tool to tighten them, and I go ahead and do it, how can you exactly tighten them such that the de-centering issue is gone? Or is it just good enough? My fear is overtightening or undertightening. Thanks.

If the mount has not come off then the de-centering will be taken care of when they are tightened evenly, don't tighten one and then the next, pinch all four first, then a bit more, then wind them on. If you are using a jewelers type screwdriver you can't over tighten them, if you have a bigger screwdriver you can s use a little care if the handle is big and gives lots of torque.

They are not Phillips heads, they are JIS, try to use the right screwdriver as Phillips can slide and round the slots.

 

[bdunbar79]

Thanks a lot for your help. I got them tightened. Do you think it's worth the risk of shooting with it tomorrow, or go conservative and use the 300 and then test the 400 at home prior to using again?

Again, thanks for your help.

 

[privatebydesign]

I am fairly sure you have the problem sorted but for a paying gig I'd air on the side of caution, I'd use the 300 unless you have time to test the 400 before.

Glad we could help.

 

[WillThompson]

Yeah a lot of my shots were from a slope or slight increase in gradient. Wonder if at such a wide aperture, if my camera is tilted downward, the focal plane is slanted enough that the face is in line with the grass in front? Oh hell I don't know, I'm shooting with my 300 tomorrow until I know what's going on and thankfully I posted these or I wouldn't have looked until tomorrow night.

That would explain why my track ones don't display this, or unless the misalignment just happened recently.

It is twice as bad when you and the subject are on a incline since the subject will effectively be tilted towards you when they are below you.

Will T.

 

[privatebydesign]

No to standing on a slope, that WILL NOT do this.

Not true.

When ever shooting down on a subject you tilt the plane of focus.

Will T.

What I meant was it would not give the results bdunbar was getting, I said there was something wrong with his lens, and there was.

 

[bdunbar79]

Thanks for the help. I used my 300 today because I just couldn't risk it, as I didn't have time to do any testing. I simply picked two locations during the day where there was a green, next to a tee, luckily the cart path turning 90 degrees to the right after the green. So I was okay and just had to give up on fairway shots. I'm going to test it, because I have track next weekend and really need that lens for that.

 

[bdunbar79]

I tested the lens today and that was the problem. Sharpness is restored corner to corner. Thanks so much for the help.

 

[Hannes]

It is a bit worrying that your lens mount came loose like that. It'd probably be worth talking to CPS about it whether they want to have a look at it to stop it from doing it again. For anything other than a several thousand dollar lens I'd advocate loctite

 

[bdunbar79]

Since I'm a CPS member, I went ahead and contacted them and yes, the lens mount needs replaced, and after it's replaced, a full set of specs will be run to make sure it's operating as it should. So when I get it back, it should be back to near original condition. I have no idea what I did to loosen it.

 

[CarlTN]

Interesting!