Lens calibration - send the body too?

Vertigo

Vertigo

Vertigo

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28 Dec 2003
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Ok so my 70-200 appears to need calibrating. After doing some micro-adjustment focus tests, it appears to be pretty much bang on at 70mm, maybe even +1, at 135mm it's spot on but at 200mm it's around the -8 mark.

It's too late to send it off to Canon for calibrating now as I'm going away in a couple of weeks but I will do when I get back. My question is whether to send the body too.

Now I know all about tolerances in both lenses and body and so forth and that they recommend you send both the lens and the body so they can be calibrated to each other but is this really necessary?

All I want is for the lens to be "linear". I don't mind if micro-adjustment is required as long as the value is the same at all focal lengths. Surely they don't need any specific body for this so is there any point sending it?

Incidentally I've never sent a lens off for calibration before. I presume I have to send it to them at my own expense but do I have to pay for their return shipping charges too? I'm a (basic level) CPS member - don't know what sort of turnaround I can expect?
 
The lens is brand new (a month old) but the body is just over two years so not under warranty.

I've already made preliminary contact with CPS but will call them tomorrow to find out exactly what the deal is. I presumed they all went to Canon Elstree but can you choose where to send them? (I know I can ask CPS all this tomorrow but just curious)
 
Presume you mean the calibration and return shipping is free under warranty but you have to pay to send it to them to start with?

Wish they did a while-you-wait service - I'd actually drive to Elstree if I could sit and wait there for a few hours while they did it.
 
D.P. said:
For zoom lenses it is not always possible to have a uniform calibration across the zoom range, 3rd part lenses tend to be especially prone to this. However, normally the differences are small and if one calibrates close to what the tele end joule be then the wide end tends to suffice due to typical DoF differences.
Click to expand...

A slight difference would be understandable, but a range of 9 isn't in my opinion. A lens, especially one that expensive, should focus properly at all focal lengths. When the adjustment range for "perfect" focus is that wide, I'd content that it doesn't meet that criteria.
 
Basically, at 200mm the lens is way off whereas at 70mm it's pretty much spot on.

I've adjusted it to -6 for now which has pretty much fixed it at 200mm. At the wide end it's now not perfect but the wider DoF means even at -6, it's still pretty close. It'll do for now but I want it calibrated to at least get the difference narrowed a fair bit.
 
A range of 3-4 would be perfectly acceptable - I'm not expecting it to be calibrated to the point where the subsequently required micro-adjustment is identical at all focal lengths - that's not reasonable.
 
Interesting - the form you download from the CPS site has the CPS logo at the top and the title "Equipment for Priority Repair".

I know the stickers of which you speak - whether I can actually find them again is another matter! :D
 
Yes I have - works well.

It's nothing you can't do manually but it just automates the process for you. As it uses a predefined algorithm to compare the sharpness of shots, it's also a little more deterministic than just using your own judgement about whether one shot is sharper than another or not. That said, the results do seem to vary a little on repeated runs but only by one point on the adjustment scale - to be expected I guess as the difference between two adjacent points on the scale is miniscule.

Be aware that, on the 5D3, Canon's API doesn't currently allow the software to set the adjustment value so instead it directs you to change it to a specific value after each test shot, which is a lot more tedious than the fully automatic mode.
 
Is it usual to get any kind of confirmation email from Canon acknowledging receipt, or not hear anything unless they actually need to contact you?

Just wondering as it was delivered to them yesterday but not heard anything.
 
Yeah it had the lurid green CPS sticker on it. Will call them tomorrow and check they've got it ok.

Of course my CPS level only gives me a five day turnaround compared to your two so it might be a little further down the queue :)
 
Well, despite all the glowing reports about Canon Elstree, I'm thoroughly unimpressed with them so far!

Zero communication. No acknowledgement of receipt or anything else. Had to call them last week just to confirm they'd actually received it ok.

CPS turnaround time should be five working days, which is today, yet I have no idea what's happening, when I'll get it back or whether they've even looked at it.

Going to have to call them again to chase.
 
I spoke to them yesterday - apparently the reason I'd heard nothing was that they were emailing me but someone had entered my address incorrectly into their system - doh.

Got a call from a technician this morning saying he was looking at it and wanted to clarify the exact issue and what body I used it on mainly. Got notification towards the end of the day that it was being despatched back to me so hopefully will get it back tomorrow or Friday :)
 
Well it's back! Won't have a chance to actually use/test it for a few days so don't yet know exactly what they've done to it but I'm just relieved to have it back in my possession :)
 
Finally got round to testing it again today. At 200mm, the sharpest adjustment is now around -9, so much the same, but at 70mm it's now -7, so much more uniform across the range and I can now easily adjust my body to it :)
 
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