Explaining the Canon Lens Line-Up

Whilst unpacking our recent move from Colorado back to Ohio (now nestled in Cleveland), I was sorting through the stacks of papers that I didn’t have to sift through prior to the move, and came across an email I had received from a reader a while back asking me if the blog had anything that explained the basic differences between EF and EF-S lenses from the Canon lineup.  I had written her back, but it never seemed to make it’s way into a blog post.  So, in reading the email, I did a search and realized I also had never followed up with something for the reading audience in general, so double shame on me!

That being said, it’s worth addressing just as an informational piece that is good to have on a site named “CanonBlogger”!  So, let’s dive right in:


Canon carries two lines of lenses, the EF and EF-S lenses.  The primary difference between the two categories is that the former is designed for their full-frame cameras (think the 1D, 5D, and 6D SLR’s), and the latter is designed for their crop factor cameras (think the Canon Rebel SLR’s, the 10D – 60D etc.).  This is not to say that the EF-S lenses are incompatible with the larger framed cameras, just that they are not designed for them.

What happens if you mount an EF-S lens on a full frame camera?  From an image perspective, the answer is simple: you’ll get a vignette around the edge of your pictures because sensor area is larger than the EF-S diameter.  While this may not sound like that much of a big deal, it can be exacerbated by the physical limitations of the full frame camera smaller lenses.  Since, I’ve personally avoided this scenario, for reasons I’ll cover shortly, I don’t have any samples of what it looks like in my own library, but here’s one from the Canon Rumors forums:


What might happen is: when the mirror switches open to let in light – if the EF-S lens is pulled all the way back to it’s widest aperture, that mirror could hit into the rear lens element, thus damaging both the camera and the lens. This is precisely why I don’t have any images of this type to show you…

You can also avoid this phenomenon by simply being careful to not dial the EF-S lenses fully open if/when mounted on a full-frame camera.  The challenge though, is remembering to do so.  I’m not sure I am ready to trust even myself to remember to do this.  Not sure if it’s in human nature or not, but we can be forgetful at times.  I can’t tell you the number of times I’ve forgotten some of the most basic things in my own shooting experiences.  I’ve done everything from forgetting batteries, to not dumping my CF cards prior to a new shoot, not recharging batteries, forgetting my tripod, and the most common one – forgetting to adjust my ISO settings in camera!  I’m not sure I would want to mount an EF-S lens onto a full-frame camera, simply because of the risk.

This is not to say it can’t be done though – because it can, and there are even adaptors available that will allow you to do this, but I would highly recommend avoiding attaching an EF-S lens to a full-frame camera!!!  The results could be economically disastrous.

The good news is, the same formula does not work the other way.  You can attach an EF lens to a crop sensor camera any time you want and you’ll run no risk of damaging either the sensor or the lens.  Why?  Because the physics of the lens elements are designed to not come as far back on the lens in the EF line as in the EF-S line.  Take a look:


Here you can see the EF-S 10-22mm lens almost comes to the back edge of the lens rim.  This is what allows for the wide angle of view you can get from this lens (one of the widest non-fisheye lenses on the market).  As you can imagine, when you get into the fisheye category, the back element can even protrude from the edge of the lens in an EF-S camera.  This is quite the opposite of the design in an EF lens:


This is the 70-200L (f4 – so a little slower than the IS counterparts that have become so popular, but the mechanics are the same.) Notice how much deeper it is between the back of the mount and where the rear element goes to?  This prevents the larger mirror on a full frame SLR from opening up, smashing into the rear element and damaging both pieces of equipment in one fell swoop.  Take a look at these two lenses side-by-side.



In general, where a vendor spends more money in R&D, the better the quality of their products versus other lines.  Does this mean that one is better than the other?  Of course not, because I have gotten some great shots from my 10-22, even the kit 18-55 and others in the EF-S category. Likewise, the EF range of lenses offer some equally amazing opportunities.  But, facts are facts, and the EF-S family of lenses encompasses 10 lenses in total:

Focal Length Focal Length
1.  10-22mm 5.  15-85mm
2.  17-55mm 6.  17-85mm
3.  18-55mm 7.  18-135mm
4.  18-200mm 8.  55-250mm

Conversely, look at the amount of R&D that Canon has devoted to their EF line of lens gear

Focal Length Focal Length Focal Length Focal Length Focal Length Focal Length
01. 8-15mm 07. 24-105mm 13. 100-400mm 19. 50mm 25. 17-40mm 31. 28-135mm
02. 75-300mm 08. 100-300mm 14. 40mm 20. 180mm Macro 26. 16-35mm 32. 24mm
03. 28-300mm 09. 35mm 15. 200-400mm 21. 28mm 27. 20mm 33. 135mm
04. 200mm 10. 300mm 16. 100mm Macro 22. 15mm 28. 100mm 34. 500mm
05. 50mm Macro 11. 60mm Macro 17. 14mm 23. 85mm 29. 600mm 35. 24-105mm
06. 70-200mm 12. 70-300mm 18. 14mm 24. 800mm 30. 24-70mm

Did I miss any?  Keep in mind, I am not counting focal lengths with repetition such as the 70-200, 70-200 IS, and the f2.0, 2.8, 4.0, etc. so these are just the focal lengths!  And it’s 4x the population of the EF-S line.  Simply put, they invest more time there, so the optics are likely better as a general rule of thumb.  However, that being said, I do think that as technology has advanced, the optics have improved considerably across the entire lens lineup!

To pre-empt the question that most will ask, I’ve bolded and made green, the lenses I have used from the lineup.  In that vein, I’ve also changed the ones that I prefer the most to PURPLE!  So, there you are – the EF versus EF-S lenses in the Canon family.  Which ones have you used?  Which ones are your favorites?  And of course, the most obvious question that we likely all are asking:  What’s Canon going to come up with next…?