EF 300mm F4 (scratching head)..

Chris Y

Chris Y

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I may be going down the wrong road here and slightly suspicious of my 300 f4..

I recently bought a 1DX and thought why not put all my lenses through to check MA on them. The 24-70 MKII & 70-200 MKII are fine however when i connect the 300mm i seem to be going around in circles with what i think may be an issue. Whilst testing, i have had the IS OFF and it has produced good quality etc. (Test carried out mounted on a tripod aimed at a bank note)

However, i turned the IS on and noticed that when you initially press the button to obtain focus, the focus points 'ride up' and when i take a shot, it produces an OOF shot or soft and then drops down to the original focus point with the motor whirling for up to 4 seconds when the shutter button initially pressed....This doesn't happen on the 70-200 MKII at all (probably as the motor is faster).

So my suspicion of soft images could be down to either 1. Me being crap.. 2. A faulty IS System.
I did send it back to Elstree last year as i had my suspicions and it came back saying it was fine after calibration to my 5DIII but i have never been 100% happy with sharpness.
Has anyone else had the 'focus ride' when mounted on a tripod with IS on? Or am i being a complete cabbage?
 
Arent you supposed to turn IS off when tripod mounted, you certainally did when i shot Canon a while back, i think the newer IS lenses can tell if it's mounted on a tripod and then compensate but older IS lenses couldnt so it needed to be turned off.
 
Yes the IS was switched off during the MA testing. But when done i turned it on for a test shot resulting in the above.

As pointed out on another forum, i understand the newer lenses can sense that its tripod mounted where as this doesn't and tires to send feedback trying to detect movement that isnt there.

Me=Cabbage!

However, still not 100% with the overall sharpness. The tests go on.
 
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Have you updated the firmware of your 1Dx. I seem to remember reading the update fixed a focussing problem on longer lenses but can't be sure as I wasn't really concentrating as I don't have a 1Dx. I've just tried looking on the Canon website but can't seem to get on it for some reason.
 
Chris Y said:
Has anyone else had the 'focus ride' when mounted on a tripod with IS on? Or am i being a complete cabbage?
Click to expand...

Gary Coyle said:
Arent you supposed to turn IS off when tripod mounted, you certainally did when i shot Canon a while back, i think the newer IS lenses can tell if it's mounted on a tripod and then compensate but older IS lenses couldnt so it needed to be turned off.
Click to expand...

As Gary says, with the 300F4, you need to switch the IS OFF if you are mounted on a tripod - this is why you're having problems when you switch the IS ON if it's still mounted on a tripod.

The new lenses (70-200 F2.8II for example) can auto detect a tripod mounting, so it isn't necessary to switch it off, but is still good practice to...
 
Andy - As per the OP, the IS was off for the testing.. Which was ok. Granted, I now acknowledge that when its on, it attempts to search for movement hence the oof. That was what I was unaware of and unknown to me.
 
Chris Y said:
Andy - As per the OP, the IS was off for the testing.. Which was ok. Granted, I now acknowledge that when its on, it attempts to search for movement hence the oof. That was what I was unaware of and unknown to me.
Click to expand...

Hi Chris

Must have mis understood, sorry. Thought everything was fine with the lens when you were testing it on a tripod with IS off and when you switched the IS on (on the tripod) this is when you were having problems - hence, just confirming you need to switch it off.

My 300F4 does sometimes jump slightly when I use the IS (handheld), but it doesn't effect anything and I checked with Canon and they said it's normal...

Hope you get it sorted out
A
 
Yep, I've tested it to death today but no matter what setting/ AF the images just aren't as sharp as I have seen on others ... :( No other issues with any of my other lenses... Perhaps am expecting too much out of a F4 lens as all my others are <2.8..

If I was rich, I'd use it as a vase and get a 300 2.8 right now! :(
 
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