# 17-40 f4 for lower light vs 16-35 f2.8



## bearbooth (Aug 28, 2012)

Another totally beginner question (it would be nice to have a Beginner's section)

I understand that 16-35 is much more $$$ and the 2.8 lets in twice as much light, also the components used are better and you get 1mm more

Question: would the IQ be so much different if you took the same photo (something like an early evening sunset) with both lens, say at a setting of f5.6, ISO 100, 20mm length, using a tripod and remote release? 

Can I assume that the shutter speed of the f2.8 would be half that of the f4? and with a tripod would the IQ be so different?

thanks, still learning


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## preppyak (Aug 28, 2012)

bearbooth said:


> Question: would the IQ be so much different if you took the same photo (something like an early evening sunset) with both lens, say at a setting of f5.6, ISO 100, 20mm length, using a tripod and remote release?


 The more you stop down a lens, the more comparable many of them become. The general consensus is that, stopped down, the 16-35 and 17-40 are very similar, and if you'll be using it a lot for f/8 landscapes, its easier to save money with the 17-40.

This is generally true with all lenses where there are multiples (non-L v L primes, etc)...if you have the ability to shoot at f/5.6 or f/8 all the time, you won't see a big difference in spending twice as much. But, you often buy the more expensive version because you need something else it does (f/2.8 allows faster shutter speeds than f/4, for example...or the f/1.4 of primes is important for depth of field control)



> Can I assume that the shutter speed of the f2.8 would be half that of the f4? and with a tripod would the IQ be so different?


At the same focal length, if your aperture and ISO are the same on both cameras, they will both give you the same shutter speed. Shutter speed, aperture and ISO are all inter-connected to set the exposure on your camera; if you lower one, you have to raise another to get the same exposure.

Now, at f/2.8 the 16-35 would have twice as fast a shutter speed as the 17-40 at f/4. That could be the difference between 1/50th s shutter speed and 1/100th, which might be the difference between getting a shot of people that's blurry, or one that is clear. The f/4 lens can't get that same shutter speed without raising ISO, which is something that isn't always ideal to do. Likewise for night photography, the f/2.8 might allow you to take a shot at 10s exposures, where you'd either need to boost ISO or shoot at 20s with the 17-40. The use cases are more specific for why you'd want the 16-35, but, when you need it, its invaluable.


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## Dylan777 (Aug 28, 2012)

After I bought 5D III, I tested both lenses. The 16-35 II is sharper wide open, and the f/2.8 is nice for handheld low-light shooting. DoF isn't much of an issue with a UWA lens. 

You will need to stop down f8 or so on the 17-40mm, otherwise the corners are pretty mushy when shooting at wide open.

At the end, I bought 16-35 II.


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## eyeu (Aug 28, 2012)

On the other hand, with the great ISO of the 5Diii, you could use a higher ISO and stop down to get some pretty amazing photos..and save a ton of money with the 17-40. .just my 2cents.


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## spinworkxroy (Aug 28, 2012)

I has the same question when i just bought my 5D3..
In the end, i went for the 17-40 F4.
Firstly, the 16-36 is alot heavier and the 5D isn't a lightweight either..the 17-40 is very light and easy to carry around
Secondly, the 16-35 was alot more expensive, 2x the price but it's not 2x better either. I got a 2nd hand 17-40 at 1/3 the price
Thirdly, with high ISO of the 5D3, i didn't see a need for the f2.8…If for some reason i needed f2.8 and even ISO12,800 isn't enough, then i'd rather just use a prime OR not shoot at all since it's probably too dark if i have to go to that extreme and is still not enough

So these days, when i shoot landscapes or long exposures, i will use the 17-40 and i almost never use it at f4 anyways for landscapes. IF i need a low light shooter, i'll use the 50 F1.4 or for a night out for dinner, i'll use the 40mm f2.8…so i didn't really see the need to spend so much for the 16-35mm. Even the 17-40 makes a better walkabout lens in the day with the extra 5mm and much lighter weight..yes, it' not a 2.8 and not as sharp wide open, but i honetly can't tell the difference when all the images go onto facebook anyways


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## Dylan777 (Aug 28, 2012)

spinworkxroy said:


> I has the same question when i just bought my 5D3..
> In the end, i went for the 17-40 F4.
> Firstly, the 16-36 is alot heavier and the 5D isn't a lightweight either..the 17-40 is very light and easy to carry around
> Secondly, the 16-35 was alot more expensive, 2x the price but it's not 2x better either. I got a 2nd hand 17-40 at 1/3 the price
> ...



I use Iphone for facebook, plus you can make phone calls ;D


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## Ryan708 (Aug 28, 2012)

Dylan777 said:


> After I bought 5D III, I tested both lenses. The 16-35 II is sharper wide open, and the f/2.8 is nice for handheld low-light shooting. DoF isn't much of an issue with a UWA lens.
> 
> You will need to stop down f8 or so on the 17-40mm, otherwise the corners are pretty mushy when shooting at wide open.
> 
> At the end, I bought 16-35 II.




The 17-40 sharpness drops fast at the corners of a FF camera. With APS-C size sensors however the sharpness goes from edge to edge. And to clear up some confusion, a F/1.2 or 2.8 or f/4 lens ALL set to f/5.6 will be letting in the same amount of light. it is only when they are set to their wide openings (f/1.2 etc...) that they are letting in more light. If you want a sharp landscape, usually around f/6.3-f/8 are sharpest, and in this case the 16-35 wont be letting in any more light than the 17-40. Hope that helps!


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## unadog (Aug 28, 2012)

bearbooth said:


> I understand that 16-35 is much more $$$ and the 2.8 lets in twice as much light, also the components used are better and you get 1mm more
> ..................
> 
> Can I assume that the shutter speed of the f2.8 would be half that of the f4? and with a tripod would the IQ be so different?



As other have explained, that is only true when shooting wide open.

What is true, and the reason why I bought att 2.8 lenses when I could - is THE VEWFINDER WILL BE TWICE AS BRIGHT with a 2.8 as with a 4.0

That is also important in low light conditions.

Good luck! Can you test and compare somewhere? How often will you use teh lens?

What camera are you using? I sold my wide lens, I rarely used it on a full frame. 24 was wide enough for 99% of my use on the 24-70.

Michael


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## BL (Aug 28, 2012)

I too struggled with this choice when I purchased my UWA back in 2006. 

At the end of the day, I ponied up the cash for the 16-35 II for several key reasons

1) Waaay better sunstars at f16: the 14 points are very distinct and not softened/ambiguous like the 17-40 gave me
2) 1mm on the wide end for me is significant and very meaningful. More than happy to pay more for this
3) And lastly, yes, occassionaly there is the need to shoot @ 2.8. Not very often at all, but I like having options


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## jdramirez (Aug 28, 2012)

I'm not going to bother with what other say and I'll just give you my thoughts which may be redundant to what others have previously said.

The 17-40 and the 16-35 are different animals entirely. One is a Camero and one is a Corvette. Both meet the minimum threshold for being nice, but only one is the pace car for races. 

The 17-40 is a little soft until you stop it down to around f/11 which isn't awful because most landscape photography is put on a tripod. But indoor photography would be affected if you don't use flash, and even if you use flash with a aperture of 11, it is still quite a challenge. 

I'd personally ignore the issue of 16mm v. 17mm. 

Question: would the IQ be so much different if you took the same photo (something like an early evening sunset) with both lens, say at a setting of f5.6, ISO 100, 20mm length, using a tripod and remote release? 

I'll defer to others to answer this question.

Can I assume that the shutter speed of the f2.8 would be half that of the f4? and with a tripod would the IQ be so different?

The shutter speed would be twice as fast at f/2.8 than it would be at 4. Again... if you are tripod mounting... it isn't that big of a deal unless there are animals in your shot and they are moving.


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## K-amps (Aug 28, 2012)

On paper the 16-35ii is wider and faster at 2x the price, but is it really 2x the lens?

In reality, these lenses are often used for landscapes and there you need great DoF, so you will use them in the f6.3 to f11 range. At this range both lenses (barring FoV) will be very similar. So in the end you might be better off with a 17-40L.

There will be situations where the 16-35mm is better and those who engage such situations will spend 2x the money, but I have not had the urge yet.

You have to consider the Filters (ND for water blur or ND gradients for Skies) will be cheaper in the 77mm thread size than the 82mm needed for the 16-35.

As for shooting wide open, the corners are mushy in both lenses unless really stopped down. Hopefully Nikon can shame Canon into releasing a monster like the 14-24mm.

As a beginner, I'd highly recommend you get a 17-40L, and then move up once you feel you need to.

For Architecture, I'd rather use the TSE-24 which is by far the sharpest of all of Canon's wide angles... it puts many Nikkors to shame as well.... it is a beaut !


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## myone (Aug 28, 2012)

When I bought my 40D, I never really consider the 16-35 due to its price. Shooting 17-40 on a cropped body eliminates the softness on corners, and 3 years using it with my 40D left me without much complains at all. After all, I saved the extra $ on some other lenses that I wanted at that time. I even shot many pics at f/4.0 on many of my vacations and even family weddings, both handheld and on tripod. The 17-40 at its price, again is a winner.

Then, I purchased the 35L f/1.4 and the 24-70 f/2.8. Since the 24-70 is on my camera all the time. If I want high quality images, I will use my 35/1.4. If I want wide angle, I will use the 17-40. Ever since I bought the 24-70 and 35/1.4, I seldom use the 17-40 anymore.

Early this year, I finally made the leap and bought 5D3. With 5D3, the 24-70 again becomes my lens of choice, followed by the 35L. The 17-40 is only used when I want ultra wide. For all other photography such as vacation, walk around, street shooting, I would reach out for 24-70 and 35. 

My point is, save the $ for other good lenses. When you build up your lens selections, you will notice the UWA (17-40 or 16-35) will be used less and less because it is just too wide. Also both 24-70 and 35 give better color and contrasts. So save some money buy the 17-40 and save the extra cash for something else that will give you more creative perspectives on your photography.

This is from my own personal experience. Hope this helps.


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## Halfrack (Aug 28, 2012)

This type of question needs to have a bit more detail. The shutter speed/iso/aperture triangle is very true, as is if this is for a crop body or a full frame. Toss in if there is a need for autofocus (works at wide open, then stops down for the photo). ISO trade offs are better on FF, while on a crop, what is and what isn't a UW lens matters...


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## marekjoz (Aug 28, 2012)

Follow this *link* to see the direct comparison. You can set different focals and apertures for both lenses to see how they behave.

This is in fact not exactly true, that when you set both lenses at f/4 or f/5.6 they would require the same amount of light. F numbers are rather calculations of physical dimensions. There is also another parameter - light trasmission (T number) which answers the question how much light is lost in lens and this one can be different for different lenses set to same F numbers. BTW: T-numbes are important parameters in video lenses, so here it came popular with cinema line announcement. 16-35 has 16 elements and 17-40 has 12 elements. The filter diameter is different. Coatings can be different. Finally it can occur, that photos made by both lenses set to same parameters can be slightly different in terms of brightness, not only in sharpness, distortion, chromatic aberration and vignetting. They would also differ somehow in contrast which finally would affect on postproduction settings applied. So I wouldn't say it's so simple.
I can say that basing on my own experience, where I cannot say that pictures are the same (in terms of brightness and postprocessing applied) when they are made with 50 1.4 and 24-105 f/4 (at 50mm) both set to F 5.6 for example, or 24-105 F/4 and 70-200 F/4, bot set to 100mm and F5.6. 
Summarizing: in most cases camera will set you similar exposure times but not always because different lenses have different T numbers! If so, then there must be some narrower or wider bounds within which they will have different exposure times set by the same camera body, in the same scene, lighting conitions and at the same f number 
I hope it didn't complicate your dillema too much


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## bearbooth (Aug 29, 2012)

thanks for all the information and suggestions!

you guys are quick on replies...........well nice


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## pwp (Aug 29, 2012)

This very recent thread may help you.
http://www.canonrumors.com/forum/index.php?topic=8879.msg160935#msg160935
It directly discusses the 17-40 vs 16-35 scenario.

-PW


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## spinworkxroy (Aug 29, 2012)

I think the BIG question is still..how deep is your pocket?
If it's deep enough, just go for the best…the 16-35…even if you don't need the 2.8, just get it because you can..
IF your pocket is as shallow as mine, then the 16-35 isn't even a consideration.
Do you already own the 24-70 f2.8? Or do you own the 24-105 f4…
Somehow people who own the 24-70 will go for the 16-35…and vice vesa  
You do get spoilt when you already have an existing 2.8 lens…


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## M.ST (Aug 29, 2012)

The EF 16-35 II is not a perfect lens, but compared to the EF 17-40 buy it or wait for a EF 16-35 III.


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## marekjoz (Aug 29, 2012)

M.ST said:


> The EF 16-35 II is not a perfect lens, but compared to the EF 17-40 buy it or wait for a EF 16-35 III.



I wouldn't like to be banned or excluded - luckily there are no more smites  - but looking at those comparison:
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=412&Camera=453&Sample=0&FLI=3&API=2&LensComp=100&CameraComp=453&SampleComp=0&FLIComp=3&APIComp=0 I can say that at all apertures starting from 4.0 up:
1. Below 24mm 16-35 has slightly better CA but worse resolution
2. Above 28 mm 17-40 is better in CA and resolution

They mostly differ in 
A. available apertures 2.8 vs 4.0 where in 16-35 using it below f 3.2 starts to be questionable because of the IQ
B. mms: 16 vs 17 and 35 vs 40

I didn't have 16-35 II so this controversial comparison conclusion comes from observing those testing charts only. I had 17-40 and it was good but of course darker than 16-35.


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## pwp (Aug 29, 2012)

No smites for you. Facts are facts.
This echoes my own experience with both these lenses.

-PW


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## EOBeav (Aug 29, 2012)

They both let in the same amount of light. The difference is that the 16-35 let's you go all the way out to f/2.8. If you're shooting landscapes (an ideal situation for the 17-40), you're rarely going to want that kind of DOF.


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## wickidwombat (Aug 31, 2012)

The 16-35 f2.8L II is also very snappy in the low light AF performance on the 5d mk3 its superb in low light wide open


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