Is There Really Any Difference Between an f/2.8 Lens and an f/4 Lens?

Aside from the price, often in the vicinity of thousands and thousands of dollars, can you actually tell the difference between an f/2.8 lens and an f/4 lens?

During my many years of photography, I think the most reoccurring dilemma I've consistently had to contend with has been the choice between a lens with a wide open aperture of f/2.8 as opposed to one that only has an f/4 maximum aperture. For context, I'm not a portrait photographer and mainly shoot landscapes in decent light, so I've never really considered the need for f/2.8 in my particular circumstances, especially when they typically cost a couple thousand more dollars and add significant weight to the overall setup. That being the case, I haven't ever considered the need for a lens that has a maximum aperture of f/2.8, but I've always been curious whether they're that much better or not. 

And that brings us to this great video brought to you by Nigel Danson. In this video, he compares two 24-70mm lenses: one that has a maximum aperture of f/2.8 and one that stops down to f/4. The first significant difference is the price, which is no secret. But thousands of dollars difference? It's a big price to pay, so you'd want to be sure of the benefits. The other major difference straight off the bat is the weight: the f/2.8 comes in at 800 g while the f/4 lens is significantly lighter at 500 g. But what about image quality and final results? I don't want to spoil it for you, so please give the video a look and let me know your thoughts in the comments below.

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Iain Stanley is an Associate Professor teaching photography and composition in Japan. Fstoppers is where he writes about photography, but he's also a 5x Top Writer on Medium, where he writes about his expat (mis)adventures in Japan and other things not related to photography. To view his writing, click the link above.

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I feel like a fallacy here is that this is like comparing a Porsche to a Prius while driving at 50mph in a straight line. Of course, they will feel the same. Do that same comparison at 120mph and its a completely different story because the Prius can't even get to 120mph.

If you are spending your entire life shooting at f/8 then yeah, the expensive and heavier 2.8 glass isn't worth the money just as the Porsche probably isn't worth the extra money to just sit in traffic. (At least if you presume for the sake of this argument that we don't care about anything other than car performance and that the social validation of owning an elite car isn't relevant)

However, when pushed to the limits, the more expensive and higher-performing choice will reveal its value.

Its always a compromise between extreme performance, cost, and size. The key is deciding what matters most to you.

I just bought yet another 2.8 prime. It took me a moment to grasp you were talking about 2.8 zooms being expensive.

Well, I was specifically referring to the comparison in this post but yeah.

Yeah, as I said in the TY comments, he needed to compare them at 1/30 or 1/15 s at f4 and a high ISO.

To be fair, Nigel does state at the start of the video "does it make any difference in **landscape** photography".

I don't think for one minute that Nigel is suggesting a cheaper f4 lens is just as good in all photography disciplines.

People sometimes read into things what they want so they can try and make their point opposite of the original intent.

Why is there always someone with these unrelated car analogies? Just make a statement

Because people have been using something called analogies to help other people understand things more clearly for at least as long as there's been a written language. Why is there always someone who feels the need to dump on other people's comments...?

Nobody is dumping it's simple criticism on an analogy that is grossly popular and quite possible unnecessary. What harm would have done in trying to convey what was intended if done straight forward? Analogies help but it can often confuse when the context is not understood. Car analogies such as this takes much away from the original subject and the intention gets lost fast

While more of a general thing, most cars can hit higher top speeds by simply disabling the electronic speed limit on the vehicle. Most will do it via a rev limit on the highest gear, e.g., some may limit you to 4000RPM at the highest gear, by disabling the hall effect sensor used for it (often a separate sensor on the transmission), will allow the a higher speed. though it is only useful on certain tracks that will provide enough straight road to hit a top speed.

PS, mods like that are 100% useless on public roads since on many common non-sports cars, accelerating from 100MPH to 115MPH will take a while, and while disabling a rev limit can get you another 20-30MPH, the acceleration rate rapidly drops, and eventually you reach a point where the engine simply isn't powerful enough reach its max RPM while also fighting the wind resistance.

Don't forget the safety aspect of the vehicle's tire rating :)

The 2.8 lens at f/4 will also be sharper as well. There's a reason the 24-70mm 2.8 is considered one of holy trinity of lenses.

That differentiation is made by the writer in the first paragraph.

There is a big difference , for example:
I had the 17mm 55mm 3.5 /4 lens that
came with my 3400 nikon , and I bought 6 months ago the 17mm 55mm 2.8 nikon.
This lens Is sharper , faster and I am not limited to just one type of fotography.

There are other reasons to buy a faster lens. If all you are doing is shooting landscapes with a 24-70 zoom lens in good lighting then yean, you can get by with a less expensive lens.
However, if you are like me and have unsteady hands then you need all the help you can get. Things like optical stabilization (or whatever the lens maker calls it), a lens that lets in more light (f2.8 vs f4) and preferably a stable exposure and not variable throughout the zoom range.
Frankly, I don't care about weight as I am not shooting day in/day out, and tripos/monopods do not work for my style of shooting/ I live in the Rocky Mountains and I hike and shoot in them.
The lenses I have range from a 15 year old full frame Sigma 50-500 without any OS/VR stuff and it is relatively slow at F5.6-f8 but I can hold it relatively steady to s Sigma 150-600 with all the bells and whistles that I am still trying to get used to. I do have a 24-70 f2.8 that I love and it does have VR and it is fun to play with.

As someone else mentioned, it is all dependent on how YOU shoot and what YOUR needs are. Being 63 and having a TBI, my needs are different than they were 10 years ago. And are different than they will be 10 years from now. Heck, I might even go mirrorless. Or go back to film. I still have my old film cameras laying around someplace....

Do you shoot landscape images at 2.8 to let more light in?

Not really, I am shooting landscapes at 2.8 because I can get a clearer image by using a faster exposure. It just so happens that a 2.8 lets in more light to accomplish this. (Sorry for the delay in responding, I just got the notification that there was a reply to my original post.)

I do like to play with shutter speed and exposure settings. The first picture is at F36 and 4/5 of a second. As the background shows, I was able to hold pretty steady. The second pic, same spot, was at F5.6 but at 1/160 of a second.

I know it may seem contradictory, but I like to play with exposure settings to see how slow I can shoot. What a faster lens does is allow me to shoot with less light to see what I can do with depth of field, slow speed and the like.

Can't post???

If that comment was to me,then no, I just didn't realize that there was a reply to my original post. I just was notified today that there was one.