sending a lens back?

snigg

snigg

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anyone know the process on getting Canon to check/calibrate a lens? I have a 85mm 1.8 and have done a load of test shots and wide open 1.8 even the centre is not sharp,should I be expecting the focus point at 1.8 to be pin sharp when using a tripod? I've read on here of people sending bad copies back but who decides it's a bad copy? heres a 100% crop,the focus point was on the TR of ultra and the U of Duracell.http://
 
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I agree and would expect it to be better than that assuming its tripod mounted given the shutter speed of 1/25
 
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SixToes said:
What tripod are you using?
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it was on a speaker stand,so no chance of any movement and also I used the camera timer.so if people agree it should be better please say and also what procees is the best to get canon to check this lens for me if it is agreed it is not as it should be?
 
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Assuming you didn't have it on manual focus, your shutter speed was substantial, and the fault isn't in the camera? Yes defo get it looked at, is it under warranty? I would speak to Fixation about it - generally helpful (Canon service centre) though I assume they will want it sending/dropping in.

S
 
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We need the whole story,

where did you buy it, was it new, did it have a warranty..if so what type, was it from a retail shop/internet sale/local dealer?

How have you tested it, what camera, how did you activate the shutter, single focus point or multi focus point, A1 servo or sigle shot?

sorry if this sounds a pain but it all helps
 
snigg said:
it was on a speaker stand,so no chance of any movement and also I used the camera timer.so if people agree it should be better please say and also what procees is the best to get canon to check this lens for me if it is agreed it is not as it should be?
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You had the camera on a speaker stand?
 
admirable said:
You had the camera on a speaker stand?
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yeah the speaker was off at the time,the stands are good quality and filled so are as solid as a rock,I would say they would offer better test conditions than a tripod.
 
How far away was the camera from the battery?
 
admirable said:
We need the whole story,

where did you buy it, was it new, did it have a warranty..if so what type, was it from a retail shop/internet sale/local dealer?

How have you tested it, what camera, how did you activate the shutter, single focus point or multi focus point, A1 servo or sigle shot?

sorry if this sounds a pain but it all helps
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no mate glad of the help,as I'm new to this I understand it may be me,the answers to your questions,


Jessops only this march,canon 40d,timer,on stand,single point focus ,single shot.
 
snigg said:
it was on a speaker stand,so no chance of any movement and also I used the camera timer.so if people agree it should be better please say and also what procees is the best to get canon to check this lens for me if it is agreed it is not as it should be?
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Maybe try a speed of about 1/160th and make sure the battery is outside the lens MFD. Put a diagonal row of batteries to see if you can see if it is front or back focusing. Also try comparing a live view shot from the same point. Move the focus ring between shots so that each shot is individually focused.

If it looks the same after all that then yes, send it back ;)
 
As Jim said above what was the subject distance, I'm a Sony user but guessing that the mfd for your lens is around a metre
Damn playing catchup lol
 
Gave it a wee sharpen

trim.jpg


trim1.jpg
 
admirable said:
Gave it a wee sharpen
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the pic I posted was straight from the camera,its the camera JPG.I thought the camera did some sharpening?,I understand that I could get the pic better with extra sharpening but am now unsure how much sharpening would be fair to do when testing? some,none,max?

so I'm a bit confused now,is there a problem or is it just a lack of post sharpening by me?
 
Are you using mirror lock up? This is exactly the kind of the shutter speed where mirror vibrations could soften it slightly.

How much sharpening is applied to jpgs depends on how high you've got it set.
Press the picture styles button to check.
 
squishy said:
Are you using mirror lock up? This is exactly the kind of the shutter speed where mirror vibrations could soften it slightly.

How much sharpening is applied to jpgs depends on how high you've got it set.
Press the picture styles button to check.
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no mirror lock up used,just checked the camera is on +3 sharpening

I also have the raw pic if it would help to post that,as the camera is set to raw and jpgs?
 
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A couple of things that need to be ruled out,

When you press the shutter button to activate the timer it will focus and then start the timer, if the camera is moved slightly whilst pressing the shutter button the focus will be out. So the camera needs to be fixed ie; tripod.

1.25th, f1.8 at ISO 100 means it must have been pretty dark, I think you need to redo this test in better light and a higher shutter speed.

Looking at your image I don't think the lens calibration is miles out but I do think you need to do a proper test....and I would just use jpeg.
 
admirable said:
A couple of things that need to be ruled out,

When you press the shutter button to activate the timer it will focus and then start the timer, if the camera is moved slightly whilst pressing the shutter button the focus will be out. So the camera needs to be fixed ie; tripod.

1.25th, f1.8 at ISO 100 means it must have been pretty dark, I think you need to redo this test in better light and a higher shutter speed.

Looking at your image I don't think the lens calibration is miles out but I do think you need to do a proper test....and I would just use jpeg.
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cheers for the help,yeah I'll redo the test in better light,I did check the focus point after the shot was taken on the monitor and it confirmed it was where I state it was,so is 3 sharpening enough to check this lens or should I be adding more,is there a standard to use to be checking this?
 
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1/25sec on a speaker stand, at 5ft? :thinking: It's a very poor test and you can tell nothing from that picture. Could be all sorts of things, and on balance the lens being the least likely.

Shoot a normal subject at normal distance in good light.
 
ok so my OCD is totally out of control now....

here are some more pics,both hand held,single centre point focusing,the first the focus point is just under the eye,on the little tuffed of feather,1/1000, 1.8,the 2nd is on the eye,1/2000,1.8,both straight out of camera,with the camera doing 3 sharpening(setting on camera sharpening is 1-7 and its set to 3) on the jgp,are these any good to tell if this lens is a good or bad copy or do I need to go back to the bttery test or get treatment for my problem?

http://

http://
 
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With that lens depth of field for a close subject at 1.8 is so small that I think you need to test it with the camera fixed in place and with a static subject to tell for sure - it's the only way to rule out user error. That was the problem I had with the lens when I first got mine - it's not easy to use at that aperture.
 
Repeat after me........

"just because my lens opens to f/1.8 it is not mandatory that I shoot at this aperture"


;)
 
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Those look pretty sharp to me! you've gotta bare in mind how small the DoF is. Some parts of the ducks will look soft because they're not quite in the plane of focus.


Try this test.
Take a portrait, or whatever kind of shot you purchased this lens for, then process it as normal and make a print on some nice photo paper.
I would think it'll look pretty darn sharp then ;)
 
Depth of field is too shallow to be sure where the focus plane actually is. Shoot a distant subject like a road rign or car number plate to minimise focusing errors.

Search 'good copy test' under my user name and you'll find several threads. Can't link because search function doesn't seem to be working ATM.
 
HoppyUK said:
Depth of field is too shallow to be sure where the focus plane actually is. Shoot a distant subject like a road rign or car number plate to minimise focusing errors.

Search 'good copy test' under my user name and you'll find several threads. Can't link because search function doesn't seem to be working ATM.
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cheers I will do that test,I think I found your post (car number plates in each corner ) I too had problems using search but then got it to work if I only used one word in the search fiield,tbh if I add a litle PP sharpening to those pics they look greathttp://

 
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