New 300mm f4 is L dilema

Have just purchased a Brand new Canon 300mm f4 is L lens, The problem i have is the lens is front focusing, No problem i thought use Micro adjustment on my 7d, the lens will only focus correctly at +18.
I then fitted my 1.4 x converter only to find the lens front focusing again.
After alot of testing i would say the microsdjusting would need to be more than +20 which obviously is not possible.
Should i send the lens back and ask for a replacement or send away for adjustment under the warranty.Any advice would be greatfully received.Many thanks.

If it's that far out, I'd have it looked at; although, it's possible that they'd need your body as well as the lens, to totally sort out the discrepancies.

where did you buy it from? if it amazon or someplace like that I would ask for a replacement. otherwise, send it in to get checked.

Thanks for your replies. Purchased the lens from an online retailer Hdew cameras ,they
suggested to send the lens to a canon repair center.
A little annoyed as it will be away for up to two weeks.

typeRsdslr wrote in post #15557179
Thanks for your replies. Purchased the lens from an online retailer Hdew cameras ,they
suggested to send the lens to a canon repair center.

Of course they did - that's what's in their best interest - not necessarily yours.

I bet B&H would've said, "Return it - we'll be glad to give your money back, or send you another lens - your choice." That's what they did with me when I had some minor issues with a Sigma 150-500.

Tom Reichner wrote in post #15557306
Of course they did - that's what's in their best interest - not necessarily yours.

I bet B&H would've said, "Return it - we'll be glad to give your money back, or send you another lens - your choice." That's what they did with me when I had some minor issues with a Sigma 150-500.

+1. Who the heck is hdew anyhow and why would anyone buy from them?

With B&H or Adorama they pay shipping to exchange it. If you send to Canon, you pay shipping. However with Joe no name, who knows if they are even reputable, you better just send to Canon and cut your losses.

Send it in. It will come back (in my experience) perfectly adjusted. Replacing it with another lens will get you one that's adjusted well enough for the assembly line.

Is "Joe no name" a canon authorized dealer?

typeRsdslr wrote in post #15557179
Thanks for your replies. Purchased the lens from an online retailer Hdew cameras ,they
suggested to send the lens to a canon repair center.

If it's been less than a week since you got it then phone them up and tell them you're returning the lens under the Distance Selling Regulations.

Thanks everyone, The retailer have agreed to replace the lens with no cost to myself for postage.
Top result.

Really can't ask for more than that. Hope the replacement works better for you

hollis_f wrote in post #15559152
If it's been less than a week since you got it then phone them up and tell them you're returning the lens under the Distance Selling Regulations.

Don't know if that's an applicable law over here Frank..i've never heard of it?

1Tanker wrote in post #15561510
Don't know if that's an applicable law over here Frank..i've never heard of it?

It's a UK law that allows you to return any goods bought online (or over the phone) for any, or no, reason. As long as you inform the retailer within 7 days of receiving the goods.

hollis_f wrote in post #15563027
It's a UK law that allows you to return any goods bought online (or over the phone) for any, or no, reason. As long as you inform the retailer within 7 days of receiving the goods.

Nice! We could really use a law like that, over here.

hollis_f wrote in post #15563027
It's a UK law that allows you to return any goods bought online (or over the phone) for any, or no, reason. As long as you inform the retailer within 7 days of receiving the goods.

I didn't know that part of consumer rights !
Thanks Frank