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Is the Canon 100-400mm a sharp enough lens?


Hello everyone,


My name is Jake Miille and I am photographer in California. I use a Canon Rebel XSi (Hoping to upgrade to a Canon 7D Mark ii if it comes out in January) as well as a Canon 10-22mm and a 24-105L. I shoot mainly railroads throughout the Western US and sometime 105mm just doesn't cut it. I have been hoping to upgrade my telephoto lens (I do have a kit 55-250 but it's... you know) for awhile. I have seen a few options and I was hoping I could get some of your opinions/advice.


The Canon 100-400 looks like a nice lens and I'm really excited about the coverage it could get me. I am not too worried about the limited aperture because railroad scenes are usually shot on f/7.1 or higher. I have heard the push/pull system can be weird but I have no doubt that I could get use to it. My one concern with this lens is the sharpness and quality. I have heard it is not the sharpest L lens out there and I was wondering how that would affect my photos. I'm a little torn/confused because the lens is Canon L series, but people have discussed it as being a little soft. Does anyone out there have experience with this lens? Is it sharp enough? Will it be worth the money?


If you wouldn't recommend the 100-400, what do you think about the 70-300L? If those two lenses are equal in quality, the 100-400 would give me a better range. Is the 70-300 actually a sharper lens?


Thanks for the help.



Well, i am not an expert. I own the 100-400mm and yes, I feel it is not a very sharp lens. I think the best use for this lens would be action shots, like sports or movin subjects where you don't expect very sharp photos. The push pull siystem is not weird at all, it is fast and easy to get used to, though i have read that with this system is easy to get dut iside the lens, since it creates some suction. This is probably true, mine got a little rough to slide, and i blame it on this. It is a shame although it is an L series, it is not weather and dust proof....


Still, I love it, because i am still an amateur i feel powerful with it jajaja, and I don't have the money to up-grade yet.


What about a 70-200L ? there are like 3 versions on the L series, cheaper than the 100-400mm and with better reviews, plus the weather and dust coated. You have a rebel or a 7d, you still gain a little bit of focal range with the cropped sensor.\





I don't really want to get a 70-200. I would be spending a lot of money to only add 95mm of L series. I would have to buy a 2x extendor which would make my lens twice as slow. Therefore the 70-200 f/4 would really be f/8. The f/2.8 options would be more expensive especially once you throw in the extendor. Therefore I am not too interested in the 70-200 models.


Thanks for your feedback. As a railroad photographer, I would have a moving subject but sharpness is important. It would be nice if Canon made a 100-400 f/4.5-5.6 II USM. The improvments to that lens would be a sharper image, weather coating, and a non push pull system.


Speaking of weather coats, have you ever tried an external weather jacket to protect that lens from the elements?

The 100-400 is a great lens. I have owned 2, the first one was stolen, and they have both been sharp. The push/pull zoom is easy to use and I have never had an issue with dust. The lens is very versatile and not just for sports. Anytime I need a little extra reach I never hesitate to use the 100-400. One reason some people may think the lens is soft is because a telephoto lens magnifies movement. To get sharp shots you need to use good techniques and as high a shutter speed as possible.

I have shot dandelions, the moon, and everything in between and I love my 100-400L.

"One reason some people may think the lens is soft is because a telephoto lens magnifies movement. To get sharp shots you need to use good techniques and as high a shutter speed as possible."


+1 on the above quote. At 400mm your minimum shutter speed should be 1/640.

Thanks guys! It seems like this will be the lens for me. After learning I couldn't use an extender on a 70-300, I have decided I will need that extra range. I almost always shoot on 1/800th or above. That should be a fast enough shutter speed to get a sharp image.


The higher aperture and need for increased shutter speed might put a little stress on my ISO. But then again I am looking to get a Canon 7D as well. That camera would allow me the extra ISO range.


Thanks for all the comments and help guys. You sured up which lens is for me.

The 100-400 is capable of producing some outstanding pictures. At 400mm one has to be very aware that the FOV is quite narrow and any movement will result in a softening of the pic. Shooting at higher shutter speeds will minimize any movement blur so don't be afraid to bump the ISO when necessary.

One thing that hasn't been mentioned is use a good tripod whenever possible. A good solid tripod will help stabilize any camera/lens combination when used properly.

hello there,
I've got this lens and and would surely recommend it. mines sharp enough and I enjoy the push/pull. I use it with an xsi as well as a 5d2. can't say re: the 70-300


The 55-250 was my first long lens and I was very happy with it for thousands of photos.  The 100-400 was a leap of faith because photography is strictly a hobby for me and the price was intimidating.  I don't regret the purchase, but everyone has different situations so their regret will vary.  For the sharpness, it was an obvious step up.  You can look at


And pixel peep.  You'll have to decide if the sharpness is enough for you.  I hand hold the lens at 400mm for birds in flight and am happy with the sharpness.  At 400mm, I adjust ISO to get a shutter speed of 1/1000.  For your use of railroads, the IS will work for you.  At its longest end, I look for full daylight.  When the sun gets lower, then I'm a monopod.


I have no experience with the 70-300L.  



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