I cannot set an F stop of 4.0 using my EOS 60D with my Canon EF 75-300mm 1:4-5.6 IS lens.

[jag1213]

I cannot set an F stop of 4.0 using my EOS 60D with my Canon EF 75-300mm 1:4-5.6 IS lens.  I have tried changing the shutter speed and the ISO and I still cannot set an F stop of 4.0.  Any recommendations?  Thanks in advance.

[jag1213]

I tried the lens on my old Rebel XTi and I have the same problem. I will try and clean the contacts on the lens. What should I use to clean the contacts?

Since the problem exists on my other camera, I don't think it is the camera settings, do you? THANK YOU so much for your help. I may need to take it in to our camera store.

[hsbn]

I normally use lens cleaner and a micro-fiber cloth. Just don't spray the cleaner directly on the contact 🙂

[TCampbell]

Canon doesn't want you to use anything abbrassive and they specifically state not to use pencil erasers.  The gold plating is thin and can be rubbed off if you use an abbrassive.

Use a cloth.  Moisten it if there's something stubborn and I'd use ordinary water.  I probably wouldn't use soap unless it was _really_ diluted.  Avoid commercial spray cleaners -- some of which will eventually eat away and corrode electronics.

[jag1213]

Thank you Tim, I am going to take it in to the camera store where we purchased the camera and the lens.  I tried a dry microfiber cloth and it didn't make any difference, that is why I decided I am taking it in to the shop.

[ebiggs1]

I doubt it is caused by dirty contacts.

[jag1213]

Any thoughts as to what the problem might be?

[ebiggs1]

Not really because you say everything else works as it should?

I hate to venture this but it may be something you are doing or have set incorrectly, Not being too familiar with the 60D other than handling one at the store, have you done a complete re-boot? You must remove the batterie(s) for a period of time.

I am assuming the 60D has two. The main lithium and a keep alive. Both need to be removed for a complete reset. If the date did not reset, the camera did not either.

A reboot will put things back to Canon default. At least than you will have eliminated anything you may have done.

[TCampbell]

I just want to confirm a few things since I don't think they've been asked yet.

Are you able to set higher f-stops (e.g. if you wanted to set it to f/8)?  I'm just trying to confirm that the only issue is that you can't set anything lower than f/5.6, but f/5.6 and higher are fine.  

Is it just this one particular lens?  Are you able to set the full range of f-stops with other lenses?

The camera will not allow you to set an f-stop that it does not believe the lens can provide at the focal length you are using.  This makes me wonder if the camera actually knows what focal length you are using.  It's possible an encoder in the lens has failed and is not correctly reporting that you are at the 75mm end of the zoom range even though, mechanically, you are.

You can test for this.

Set the lens to the 75mm focal length and take a photo of anything (the f-stop wont matter).  If you'd like... post the photo either here or on another site (and post the link to it) but DO NOT STRIP THE EXIF DATA (that way we can use an EXIF viewer to look at the focal lengh being reported by the lens.)

You can also view the data by using Canon's DPP (DPP = Digital Photo Professional.  Many other utilities can read this as well, but you got a copy of DPP on the media disk that came with your camera.)

Copy the image from your memory card to your computer.  Launch DPP.  Navigate to the folder where you put your image.  Select and double click the image to open it.

With your mouse over the image, right-click the mouse to activate the pop-up menu.  Select the "Info" option (it'll be at or near the bottom.)

This will open the info window which has two categories (tabs) at the top.  You want the "Shooting Information" category.

On that list, you're looking for two rows:

Lens  -- this should correctly show the lens that was used.... e.g. it should list your EF 75-300mm f/4-5.6 IS lens.

Focal Length -- this SHOULD correctly indicate that the lens was at 75mm.  If it fails to report that the lens was at 75mm (and if you're sure you were at 75mm) then the defect is almost certainly in the lens (e.g. possible the encoder has failed) and would need service to repair it.

[jag1213]

I am able to set higher f-stops, from 45 down to 5.6.  I just cannot set anything lower than f/5.6.

Not having trouble with my other lens.  Just this lens and I tried it on my older Canon Rebel XTi and even at 75mm the lowest is f/5.6.

I just took a photo using the Program mode.  I looked at the properties using Picasa.

It says that the lens is 75-300mm f/5.7-45 - which is not correct.

Focal Length is 300mm, which is not correct.

I just checked older pictures and found that the last time the Focal length registered 75mm was in March, 2013 for this lens.

The reason I didn't use the DPP is because the CD is in a storage box and not easily accessible.

Do you know if the encoder can be repaired?  If so, do you have any idea of the cost?  I know my lens is old, but it has functioned well.  The only reason I found out about this problem is because I am taking a class to learn how to use manual settings and I was checking all the different f stop settings.

Thank You for your detailed help.

Jane Ann

[TCampbell · Accepted solution]

You would need to contact Canon for repair options and prices.  All we know at this point is that it's not correctly reporting it's focal length to the camera -- we don't know why.  It should be serviceable.

You would need to tell them that the lens always reports 300mm as the focal length even when set to other focal lengths.