Really struggling with canon 500mm

nick197

nick197

Suspended / Banned
Messages
135
Name
Nick
Edit My Images
Yes
Hello everyone, I'm in need of advice. Basically a lot of my shots taken with my 500mm f4 mk2 and 7d are way over exposed. It's okay when using aperture priority until you get to around f10 etc, then it starts over exposing the image. When using shutter priority it's impossible to use 1/200 or under etc as it's just a white image. I've got a 300mm f4 lens and when used back to back using manual to fix the ISO, aperture and shutter speed. The 300mm is fine and the 500 is way over exposed, the settings were 1/200, ISO 100, f32. Basically I love aviation photography but it's imposible to shoot propellered stuff as it's all over exposed :(.
 
Could it be the diaphragm is sticking? You are 'asking' it go full travel. Could you use an ND filter to stop the lens stopping all the way down?
 
The camera thinks it's getting the right exposure as the compensation bar whilst focussing is in the middle. It's strange how the 300mm is bang on and the 500mm is way out. I don't really want to use an ND filter as when I want to shoot jets I'll have to take it out.
 
nick197 said:
The camera thinks it's getting the right exposure as the compensation bar whilst focussing is in the middle. It's strange how the 300mm is bang on and the 500mm is way out. I don't really want to use an ND filter as when I want to shoot jets I'll have to take it out.
Click to expand...

Could still be a sticky diaphragm. I was thinking more in terms of testing it rather than in operational use
 
is there anyone on the forum near by that you could just test on their body?
 
Hopefully I'll be able to borrow my uncles 400d tonight.
 
aperture priority until you get to around f10 etc
Click to expand...

I think this is your clue... if it works on the 300mm then that's the camera mechanism checked. Switch to the 500mm, the exposure reading you say is correct but after/smaller than f10 it starts being overexposed... my guess is that's where the diaphragm is starting to stick ~ f10 - f32
 
Unfortunately I don't have an ND filter that fits. I've only just got this lens, I bought it brand new from wex a few months ago.
 
Try taking a long burst of a fixed subject using manual exposure settings. See if the issue is consistent. Do it again on AP and then again on SP. Random variation in exposure (especially with it all set to manual) points to a mechanical issue with the diaphragm, perhaps.
 
Ok... in the olden days you could swing the back open without a film and see what the diaphragm was doing. :(
 
Is it easy to fix or is it a canon job? Thanks for all your help
 
If you bought it from WEX get it back to them.... I wouldn't even begin to attempt to fix it myself if it's a few months old and was bought new.

I might even be inclined to ask for a replacement - depends how many months is a few ;)
 
Literally 2 months, winkyphoto the problem is pretty consistent.
 
nick197 said:
Unfortunately I don't have an ND filter that fits. I've only just got this lens, I bought it brand new from wex a few months ago.
Click to expand...
send it back, no other answer required to be honest.
 
nick197 said:
The camera thinks it's getting the right exposure as the compensation bar whilst focussing is in the middle.
Click to expand...

Which is what would happen with a stuck aperture. The metering is done with the lens wide open, the bar shows what the exposure will be when the lens stops down to the chosen, or calculated, aperture.
 
I have the same type of lens also purchased from Wex in mid February & touch wood mine is fine. I'd without hesitation call them and get it exchanged or at least checked out

I've found them very understanding & helpful in the past.

Additionally, you could try the Canon UK site. I've contacted them a few times vide e-mail over the years with various issues and they're pretty quick at replying.

Are you registered with CPS? If so, you should have been given details of the person at Canon who is 'your rep' so to speak.
 
Last edited:
Really forget anything else other than sending it back. Two months is nothing.
 
OK, as some people have suggested, it looks like a sticky aperture diaphragm. It's worth confirming that before you do anything, especially as it will only take 2 minutes.

Here's the procedure.
1. Pick a target which isn't going to give your camera's metering system any difficulties. A patch of grass or a shrub is fine. Or even a wall indoors. The important thing is that you should be able to guarantee that, if there's any difference in exposure from one shot to another, it's caused by the hardware (aperture, shutter, etc) and not the software.
2. Set camera to aperture priority and make sure any auto-ISO is off (ie ISO is fixed) . Shoot target at f/4 then at each aperture stop all the way down to the minimum (f/32 or whatever).
3. Examine and compare the exposures. Obviously they should all be identical. If you see that, beyond a certain aperture they're all over-exposed, that indicates that the aperture diaphragm is sticking and not stopping down all the way.
4. Set the ISO to two stops faster and repeat steps 2 and 3. This means you'll be taking the shots with a different set of shutter speeds. If the results are the same, it confirms that the problem is the aperture diaphragm. If they aren't, something more complex is going on and you should come back here and describe your results.

Incidentally it would be useful to note whether the images get progressively more over-exposed as the aperture which you set gets smaller. If they do, it indicates that the aperture just won't stop down beyond a certain value, which points to a physical defect in the diaphragm. If they don't (eg if they're all over-exposed by a similar amount), it suggests the problem might be lubrication of the diaphragm.

If the problem is the diaphragm, it's a very quick and easy warranty fix. By all means speak to the retailer, but you're likely to get the lens back into your hands sooner if you send it direct to Canon at Elstree. (That's what the retailer would do anyway, so you might as well cut out the middle man.) The procedure is described on the Canon website and there's a warranty repair form to download and fill in.
http://www.canon.co.uk/Support/Consumer_Products/Repair_Information.aspx

Good luck!
 
Not sure if you can see that far inyo the 500, but could one not just dial in f32 and press the DoF Preview button whilst looking down the lens?
 
hollis_f said:
Not sure if you can see that far inyo the 500, but could one not just dial in f32 and press the DoF Preview button whilst looking down the lens?
Click to expand...
You probably could. But if I've understood the OP correctly, what he'll see is that the aperture diaphragm stops down. The question is whether it stops down far enough, and that might be hard to evaluate by eye. If it won't go beyond say f/11 then that ought to be discernible by looking at what happens when different apertures are set. But if it's just not quite getting to where it should due to poor lubrication, that would be difficult to judge. Looking at the resulting exposures would be easier.
 
Thanks everyone for your help. I've done the test StewartR and the over exposure gradually gets worse form F4 (were the exposure is good) all the way up to F32 where its pretty much just a white image. This result happens at both ISO100 and ISO320.
 
In which case I would say it's completely stuck!

Back to Canon or WEX then. If it's only 2 months old I'd try for a new replacement rather than send away for repair. You could argue the date it started to happen from EXIF data of the over-exposed shots?
 
Yep that's what i'll do, I'll send it back to WEX so i have the option of a replacement lens. Thanks again for all your help, This is a great forum :)
 
nick197 said:
Yep that's what i'll do, I'll send it back to WEX so i have the option of a replacement lens. Thanks again for all your help, This is a great forum :)
Click to expand...

Let us know what happens & how you get on. Good luck. I doubt Wex will give you any issues.
 
StewartR said:
You probably could. But if I've understood the OP correctly, what he'll see is that the aperture diaphragm stops down. The question is whether it stops down far enough, and that might be hard to evaluate by eye. If it won't go beyond say f/11 then that ought to be discernible by looking at what happens when different apertures are set. But if it's just not quite getting to where it should due to poor lubrication, that would be difficult to judge. Looking at the resulting exposures would be easier.
Click to expand...

It is not difficult to see. Press DOF preview and then turn the aperture wheel from wide open all the way to a pinhole. With every click it should get visibly narrower - not very technical, is it?
 
if its just slightly sticky then you might not be able to tell, as the apature just closes for the exposure, but f32 should look extremely dark through the viewfinder :D
 
It should be very easy to check the aperture diaphram is working by using the DoF preview button. If you set the aperture to around f/11 then look at a bright scene through the viewfinder and press the preview button, the image should get markedly darker. If it only gets a little darker then it's sticking at a wider aperture.

You could try this progressively, starting wide open and knocking the aperture up a stop then testing with the preview button alternately and the image in the viewfinder should get darker every time. If it stops getting darker you've found the sticking point.
 
Thanks everyone for your help. I rang WEX yesterday (Monday) and they tried to organize a courier for today but failed as they are struggling to organize a courier due to the value of the lens, I find this strange as they delivered all okay. Anyway they're trying to rearranged a courier for Thursday as that's the next day someone is in all day. I suggested them sending a replacement as soon as they receive the faulty item, They said they probably couldn't send a replacement and even if they could Canon have to see the faulty lens first. They also said it could take up to 6 weeks for the repair, So it's looking unlikely i'll be able to take it to the Mach loop next Thursday :(.
 
Take the fight to them.. its under 3 months old and its obviously not fit for purpose. Ask them for a replacement that is your right http://www.findlaw.co.uk/law/consumer/consumer_protection/138.html

Don't back down and ask to speak to the manager not the sales people, say you won't accept a repair ue to the cost of said item. They may still try and make you wait but push for it now. if they do insist you wait make sure it is a new one not the one you sent in.

If this is also used in a business you are entitled to claim expenses if its has cost you a loss of earnings
 
Last edited:
pmac said:
Take the fight to them.. its under 3 months old and its obviously not fit for purpose. Ask them for a replacement that is your right
Click to expand...

Nope. It is your right to demand that the retailer rectify the situation, but you can't demand a replacement.
 
Of course your first recourse should be to WEX, who I'm sure will do all they can, but if that fails then I'd call Canon Elstree directly. CPS or not, I'm sure they'd do all they can to help you out given the cost of the kit and how new it is.
 
nick197 said:
Thanks everyone for your help. I rang WEX yesterday (Monday) and they tried to organize a courier for today but failed as they are struggling to organize a courier due to the value of the lens, I find this strange as they delivered all okay. Anyway they're trying to rearranged a courier for Thursday as that's the next day someone is in all day. I suggested them sending a replacement as soon as they receive the faulty item, They said they probably couldn't send a replacement and even if they could Canon have to see the faulty lens first. They also said it could take up to 6 weeks for the repair, So it's looking unlikely i'll be able to take it to the Mach loop next Thursday :(.
Click to expand...
I had a similar issue with a Nikon lens. Park Camera refused a replacement until Nikon had seen it which I figured was fair enough. I called Nikon who sent me a sticker to put on the box at their risk and cost . So far this lens has had a new AF motor, focus brush and VR unit. Total so far is 1 year old and 4 trips to Nikon, the longest visit took around a month.

You probably won't get a replacement but hassle Canon enough and they will eventually fix it and at their cost. I'm still not sure I trust the lens but it's behaved for 2 months now since the last repair so maybe it's finally fixed.
 
When you bought from WEx, you agreed to their terms and conditions, which include the following:
4.7 Faulty goods: You will always have the option of an exchange or refund if the fault occurs within 28 days of delivery. If there is a fault with your product within six months of delivery but after the first 28 days, we will offer a repair in the first instance. As an exception you may be offered an exchange or full / partial refund. After six months but within 12 months we will offer a repair only. In all cases we reserve the right to inspect the product and verify the fault and, if no fault is found, return the product to you. No refund will be processed until the returned goods have been received by us and an appraisal made as to any fault. This promise does not cover faults caused by accident, neglect, misuse or normal wear and tear.
Click to expand...
And also, to address the point raised by our friend who said you were entitled to compensation for loss of income:
8.4 We will not be liable, in contract, tort (including, without limitation, negligence), pre-contract or other representations (other than fraudulent or negligent misrepresentations) or otherwise out of or in connection with the Agreement for: any economic losses (including without limitation loss of revenues, profits, contracts, business or anticipated savings); or any loss of goodwill or reputation; or any special or indirect losses suffered or incurred by that party arising out of or in connection with the provisions of any matter under the Agreement.
Click to expand...
 
Last edited:
I don't see how there T&C can contradict UK and EU laws???

http://www.which.co.uk/consumer-rights/regulation/sale-of-goods-act
http://www.theguardian.com/money/2011/apr/17/consumer-rights-refunds
http://sogahub.tradingstandards.gov.uk/explained (3 & 5)

it would be worth contacting http://www.adviceguide.org.uk before you go any further. 6 weeks is an unacceptable time to have to wait especially for such an expensive item and very new item, thats nearly as long as you had it. would you accept this if it was a new tv or car i think not, so why except it here. Don't let them push you, speak to citizens advise and even contact a lawyer, explain to them the laws and that action might be taken, you may be sup prised how quickly they back down. Half of the sales team don't even know that you actually get 6 years against faults not 1 year as they make out.
 
You must log in or register to reply here.
Back
Top