twosummers Loc: Melbourne Australia or Lincolnshire England

Hello my friends.

I've been using a Canon 16-35mm F4L lens for my real estate work for a couple of years (now on my EOS R). Results have been terrific but (of course) I'm never completely satisfied. I've been looking at the 2 x RF wide angle RF zooms from Canon - one is a 2.8mm and their new one is the F4. Both now available for similar price at around £1,800 (UK). Both very expensive.

But a solution to my GAS enigma appeared in the last few days when Canon released their new RF prime 16mm f2.8 - now, given that almost all of my interior shots are taken at 16mm I have decided to order the prime (it's available for just over £300 (UK) which is a much more comfortable purchase decision and if all goes well I can dispose of my EF Zoom for more.

Finally here is my question:

As I shoot at almost always F8 (always on a tripod for interiors so shutter speed is not an issue) is there any intrinsic value of a faster lens in terms of image quality (as in I don't see the need to go down to f2.8) if I set my aperture to f8 or f11. Of course I can test this when I get the new prime (a month away from delivery).

I had this dilemma when considering the 2 RF zooms with the f2.8 lens price coming down to match the new F4

So to summarise (and add a supplementary)

Is an f2.8 lens likely to be any better at f4 than and f4 lens at f4 in terms of image quality? and
Is a prime lens intrinsically better (IQ) than a zoom?

Sorry for the long winded wording - I hope I've phrased my question well enough

As always

Keep safe

Alphabravo2020

At f/8 your hyperfocal distance is about 3.5' so the entire room will for sure be in focus. At f/4 the hyperfocal distance is 7.5' which should still keep everything except maybe near furniture in focus, say.

I don't know these lenses specifically. I'm sure someone else can answer the comparison question.

LFingar Loc: Claverack, NY

As I recall, lenses tend to have a 'sweet spot' as far as aperture. An f/4 lens might shoot best at f/6.3 or 7.1, for example. An f/2.8 lens might shoot best at f/4 or f/5, so, you might get slightly better results with the f/2.8 vs the f/4. Although new lense technology is making this less of a factor, primes are generally considered to do a better job then zooms. All depends on the lenses in question. From the little I have read about the RF 16 f/2.8 STM it seems to be an outstanding lens with low distortion. If I were shooting constantly at 16mm and f/4 I wouldn't hesitate to buy it.

CHG_CANON Loc: the Windy City

To your question, is an f/2.8 lens better than an f/4?

At f/2.8 - yes, at f/4 and smaller - no.

In the old DSLRinosaur days, the wider aperture could enable better autofocus given the aperture is held wide open on the DSLR until the shutter is pressed. But for mirrorless, this doesn't apply.

Although not free, the new RF 16mm prime is cheap enough to justify having, especially if you can analyze your image portfolio and confirm you already shoot frequently at 16mm.

The EF 16-35 f/4L IS is as sharp as Canon can produce. I think the RF versions are even better, but you really have to know what / where to find these subtle improvements. Unless you're blowing up and printing your real estate work as art, you're unlikely to find / demonstrate any difference between the RF lenses in your work compared to the already excellent results of the EF lens. The RF 16mm prime should deliver less distortion making your editing process less cumbersome. The compact size of the RF lens benefits too from not having to use an adapter.

TriX Loc: Raleigh, NC

I would just add that you cannot assume that every lens is sharper 2 stops down from wide open or that f8 or f11 is the “sweet spot” for a particular lens. Some lenses are sharpest wide open, some 2 stops down - depends on the particular lens - testing is the answer. Also when you’re shooting with a deep required DOF, you’re balancing increasing DOF against increasing diffraction, which kills sharpness as you stop down. With a FF, I try to keep aperture at f8 or wider for max sharpness, and f11 is my absolute limit except in very special circumstances.

Orphoto Loc: Oregon

There is no pat easy answer. Some, but not all, of the better lenses maintain their edge over the others even at mid apertures like f8. If you are really pursuing intrinsic quality know that on higher resolution bodies diffraction is starting to kick by f8 and definitely by f11. Have fun with the new lense and trust your own comparisons with the current lense more than the henhouse chatter here.

Scruples Loc: Brooklyn, New York

I have used a tilt-shift lens for some unique and pristine results. I am not very fond of a photograph of a building or a room that suffers from distortion that looks as if it is falling backwards. I keep a prime 24mm f3.8 T-S lens in my bag for just such opportunities. I do not get a fish-eye effect unless close-up to the subject.

Canisdirus

Two lenses of equal quality...one an f/2.8...the other an f/4.

Typically the f/2.8 adjusted to f/4 will outshine the lens that starts at f/4.

davidrb Loc: Half way there on the 45th Parallel

Seems you enjoy drinking the kool-aid of photography. Image quality is dependent upon several factors, and generally speaking the prime will out-shine the zoom in that respect. The biggest difference is f/2.8. This allows you to do more with the lens than the f/4.0. Canon makes several lenses that are available in both f/2.8 and f/4.0 and the diffenrence is not just price. For a better idea of the differences see Brian Carathan's the-digital-picture.com or John Greengo at the creativelive.com site. Both will give you a much better understanding of the differences of the two options. ANd both sites deal with in-depth details of photography. Here's a relative unknown secret: join Brian Carnathan on a shooting trip and you will learn more than you ever knew existed about this subject. Spent a week in RMNP chasing elk with him, best money I ever spent.

rlynes Loc: Wisconsin

When given the same situational parameters and aperture requirements, I'll always go with the prime lens over a zoom covering the same focal length.

Even though some quality zooms are really sharp, the primes just seem to have a bit less distortion.

jeep_daddy Loc: Prescott AZ

You have answered your own question (pretty much). No, you don't need to spend extra money on a fast lens if your style of shooting doesn't require it. Yes, lenses are offered in slower and lower prices that are just as sharp as the more expensive fast lenses. Some of the lenses that are slower also have IS included while the more expensive fast lens does not. The 16-35 comes to mind. The f/2.8 does not have IS and the f/4 does for half the price.

User ID

Yes and yes.

User ID

Typical UHH waaaaay off track.

User ID

Amen.

Simple answer to simple questions.

The OP’s question very specifically asks about *the likelihood* of improvement. So the only realistic answer is a simple three-letter word: “Yes”. No qualifying remarks needed.

Any other replies loaded with pointless pedagogy are just theatre of the ego.

TriX Loc: Raleigh, NC

Right answer(s).