Canon rf 70-200 comparison between f4 and f2.8

[Robmae]

I'm trying to decide between the Canon RF 70-200 2.8 and the Canon RF 70-200 f4

Price, weight and the wider aperture are the only three differences I can determine. I've had the opportunity to test out the 2.8 and used it at F4 just to see if I can be happy with that being my widest aperture and I definitely can. My question is: Are there any other differences between the two lenes? If I were to take the exact same picture with both lenes and shot at f4 on both of them would there be any difference in quality, sharpness, etc? 

thanks so much. 

Robin

[wq9nsc]

Robin,

Keep in mind that focus is going to be a little bit faster with a f2.8 lens because it lets in more light.  If fastest possible AF is important to the type of photography you do, then that is a consideration.

I haven't used either of the RF lenses you are considering, but even with excellent quality glass a lens stepped down one stop from wide open is typically sharper than a lens shot wide open.  How important is this?  To me, with quality lenses it isn't a deal breaker because both of these Canon lenses will perform very well so unless you are in the "pixel peeping" camp looking for every possible aberration the difference will be so small as to be unimportant.

The weight (and cost) of smaller aperture glass is very compelling and if you are sure that f4 will cover your needs then it is a good choice.  I shoot mostly sports, and a little wildlife, and for what I do the extra expense and weight is worth going for f2.8 but that isn't the case for a lot of photography.  But one last bit of advice:  high quality glass is something that you will use with many different camera bodies over time.  I still regularly use a couple of the L series f2.8 lenses I bought with my first 1 series Canon body back in 2005 and they continue to perform beautifully.  Image sensor and AF technology isn't changing as rapidly as it did a few years ago BUT camera bodies will continue to evolve and advance faster than the lenses so buying the best lens now results in a great piece of gear you will continue using long after your present camera body has been retired.

Rodger

[justadude]

Keep in mind that all other things being equal, will there ever be a time in the future that you wish you would have needed the F/2.8?  I don't use my Canon 70-200mm F/2.8L often because typically I shoot wide.  However, when I do use the 70-200, most of the time I am using it at F/2.8.  I would personally be disappointed with F/4 for what I shoot.

That being said, most of my shots with this lens are either fast moving people, wildlife, etc. or landscapes in the evening with lower light.  It depends on what YOU plan on using it for now, and might use it for in the future.

[Robmae]

Thank you Rodger and Gary. You both told me what I didn't want to hear and that is that even though I'd be happy without the 2.8 now there may come a time when I NEED it. My go to lens is my RF 15-35mm, f2.8--(an AMAZING lens), but occasionally I need to get closer and hence the search.  What (still) attracts me to the f4 is the weight. Not so much for carrying or even hand holding, but that it may be easier to mount on the camera quickly when I'm out in the elements. Thanks again for your replies. I'll torture myself for at least a few more days before I decide. 

[justadude]

"I'll torture myself for at least a few more days before I decide."

The sounds like me whenever I purchase ANYTHING over $100.  😄

"there may come a time when I NEED it."

What do you see yourself photographing with this lens - now and in the future - that may be low light, or fast moving?

Also, a question for my benefit, please.  Have you used your RF 15-35mm on night skies?  I'm looking for feedback from someone who has.  I'm considering if it would be a good upgrade for my Rokinon 14mm (which I love).

[ebiggs1]

"...I'd be happy without the 2.8 now there may come a time when I NEED it."

Going from f4 to f2.8 is one stop. The numbers may seem to be farther apart but in lens terms they are one stop. 90% of the time one stop is not going to be the difference between you getting the shot or missing the shot. Even made more so in this new world of cameras with better and better high ISO performance.

Now you can make the argument that DOF is reduced and sometimes that is desirable but again in this new world of editors like Photoshop even that is less and less a factor. If I were to make the decision I would use cost, weight and size before I would consider the f-ratio. The lens you use is always better than the one that sits at home.

[Aurora4233]

I'm a completely thrilled owner and heavy user of the RF 70-200 f2.8 and I'm also extremely conscious of size and weight because most of my shooting is over several hours and I have to lug everything.  I would never discourage quality wide aperture f2.8 and wider lenses for the images and performance they produce, however for less cost than the 2.8 and less size/weight overall you could roll with the RF 70-200 f4 AND an outstanding RF 85 f2, RF 50 f1.8, or my favorite RF 35 f1.8 for the wide aperture work.

You haven't said a lot about budget so if that's really not an issue then like others have said just get the amazing 70-200 f2.8 so you never regret it.  If size, weight, AND budget matter than consider my suggestion above.  I tend to find that if I'm not specifically looking for the f2.8 'look' than even the f4-6.3 of my RF 24-240 is perfectly satisfactory then I pop a stellar wide aperture prime on for a handful of portraits or detail shots.

You'd never be disappointed with a 70-200 f4 and it's a breeze to carry around, just be honest with yourself about your style of shooting as to whether the f2.8 depth of field will be something you'd regret not having (although cheating with a cheap prime can smooth over that regret quickly, effectively and inexpensively 😉 )

[ebiggs1]

"I'm a completely thrilled owner and heavy user of the RF 70-200 f2.8 ..."

In Lightroom set the filter to show how many shots were at f2.8. It may surprise you. I agree I would  never tell someone not to buy f2.8L lenses since for myself all my main most used trio are f2.8L lenses. But in reality how many shots are at f2.8 says something, too.

Yes, there are valid reasons for buying each over the other besides the one stop advantage or the lack thereof.

[Aurora4233]

I primarily shoot in Av unless I'm shooting jets then it's TV 1/2000ish so I do know if the 2.8 is on it's shooting in 2.8 cause that's really the reason I put it on.  There is something magical about that lens at 2.8 and if that's not what I'm looking for then the RF 24-240 or the RF 100-400 is on there at whatever f they can muster.  If I don't care about weight or want slightly better f and quality I'll roll out the RF 100-500.

I'm definitely aware the camera doesn't pick 2.8 (or whatever the lowest f is) if it's given a choice so you'd be right about few being at 2.8 aperture if I wasn't forcing it.

** Bonus since we're on camera settings - I said I shoot in Av but I lied, I actually shoot in C1 that I've programmed as Av with a 1/250 minimum shutter so I get to control the f but don't have to worry about the camera picking 1/50th when kids are running around.  Both of our bodies can handle insane ISOs so I've really taken that off my cross check and it's all about picking my f and if necessary I switch to C2 that I've programmed for Tv with a starting setting of 1/2000 (which usually results in a wide open f).  I have C1 and C2 set like that on both bodies so I'm in C1 for the crowds with low f unless it's a group shot then I push up to f4 or f5.6 for a few shots then back down to f2.8 or whatever is available.  C2 if jets are whizzing by then back to C1.

I've always enjoyed tweaking the Cs to whatever I need since I can't always trust straight Av.

[ebiggs1]

More understanding how you shoot, if you did do as I suggested in LR, I am certain you will find none of your shots are at f2.8. Only the ones where you made a conscientious decision to lock in f2.8 yourself will you find any. However that isn't the only reason to consider the Canon RF 70-200mm f/2.8 L IS USM Lens as it has other design benefits that make it the better lens. As always the question remains is it that much better and/or is it the reason you get shots that the f4 model couldn't get. My single assertation is f2.8 vs f4 is not the reason.