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Author Topic: Please explain the need for f2.8 zooms  (Read 12509 times)

Marsu42

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Please explain the need for f2.8 zooms
« on: January 30, 2013, 06:28:31 PM »
The standard lens requirement for shooting events/weddings seem to be a combination of 24-70/28 and 70-200/2.8, I read both are nailed to a pro's camera 90% of the time (though I have problems doing the maths :-))

A lens with a larger aperture afaik has three advantages: better af on some bodies, better subject isolation/creativity (just one eye in focus) and last not least a "fast" lens is required for "low light" shots.

My question rose when I read the great book "Captured by the Light" by David Ziser who - believe it or not - writes that f4 to f5.6 (for convenience or added safety) is his bread and butter setting for posed candid wedding flash shots, and he used the 5d2 at that time.

Question: So according to this f2.8 is more important for available light and movement shots, but if that was case with the 5d2, I'm confused why still seems to be still valid with the 6d even though it's about 1 stop better ... either f2.8 was borderline in the past, or f2.8 - 1stop = f4 would be sufficient now - or am I missing something here?

Disclaimer: Please forgive slight traces of irony, this ia a real question because I don't entirely understand the issue, it's great people get whatever gear they like for any purpose they want.

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Please explain the need for f2.8 zooms
« on: January 30, 2013, 06:28:31 PM »

Drizzt321

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Re: Please explain the need for f2.8 zooms
« Reply #1 on: January 30, 2013, 06:41:23 PM »
Well, as Ziser said, f/4 or f/5.6 would be better since it gets more of your subject(s) in focus, and with a strobe you get plenty of light while stopping down further would make it harder to get any of your background in the image, it'd end up basically just being extremely sharp, or you'd see drastically more shadows from the strobe.

The thing to know about the 6D, is it's not really considered a 'professional' camera as such. Sure, it's a fine camera, but features and build quality is generally not up to 'pro'. Heck, Canon only calls the 1D-series as 'pro' cameras, everything else isn't.

When you say 1 stop better, are you just talking about sensor noise performance or AF sensor performance? Even though the center point AF sensor works fine with f/4 lenses, I believe it also has a double cross-point sensors there which are likely only available on an f/2.8 lens. Thus, you still get the point where your AF will likely be improved by having an f/2.8 lens, even if you take the shot at f/4 or f/5.6, even in available light.

The other factor is, if you could choose between f/2.8 or f/4, and the difference was ISO 3200 vs ISO 6400, which would you chose? If ISO 6400 is perfectly fine with you, go for it. If you want to drop down to ISO 3200, or increase your shutter speed while staying at ISO 6400, then you'd need to go for the f/2.8 lens.

There is also another thing that you may not think of, is that lenses wide open generally don't perform their best. I'm referring to resolution, CA, etc. f/2.8->f/4 can often make a difference for a lens, and f/2.8->f/5.6 can make a big difference. That's why the top end primes go to f/1.2-f/1.4. Sure, being able to shoot wide-open and get pretty good performance is great, but if you stop them down to f/2 or f/2.8, you get some really great performance while still being able to keep higher shutter speeds.
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wickidwombat

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Re: Please explain the need for f2.8 zooms
« Reply #2 on: January 30, 2013, 06:42:11 PM »
basically having a wide aperture available is like a condom
its better to have it and not need it than to need it and not have it :P

f2.8 gives much nicer shallow depth of field shots than f4 but probably both eyes will be in focus the one eye in focus thing is more the domain of fast primes

typically at weddings I'll either be shooting my 85 at f2 maybe f2.8 for more people in the shot and occassionally f4 or 5.6 but really i use this lens for portraits and couple shots
I use this lens more now than i do my 70-200 f2.8 since at f2 its sharper than even the 70-200 is at f2.8

I'll shoot the 70-200 at all sorts of apertures depending on the shot.
for the bride and groom walking down the isle its much better to stop down and play it safe
since using servo and how fast it all goes off there isn't alot of time to mess around and a redo isnt an option

the 16-35 i'll shoot at everything from f2.8 to f11 depending on the shot having 2.8 on this lens is a godsend with the 5Dmk3 for receptions (same goes for walking down the isle shots with this lens, stopped down is better) and its a fantastically fast focuser in low light, really really impressive on the 5Dmk3.

I'm looking forward to getting a sigma 35 f1.4 too and i just hope they come out locally soon before my next wedding shoot!
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Marsu42

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Re: Please explain the need for f2.8 zooms
« Reply #3 on: January 30, 2013, 07:02:39 PM »
When you say 1 stop better, are you just talking about sensor noise performance or AF sensor performance?

My question is purely about sensor performance and why f2.8 will stay that important forever.

There is also another thing that you may not think of, is that lenses wide open generally don't perform their best.

... unless you're scraping together the money for a Canon 24-70L2

basically having a wide aperture available is like a condom
its better to have it and not need it than to need it and not have it :P

Ok, thanks for the answer from a real world pro, so you're on the side that even f2.8 isn't really "fast" enough and it just happens so that the fastest zooms available are f2.8. So if I understand you correctly you'd rather go with a Tamron f2.8 + a faster prime like the Sigma 35mm than a Canon 24-70/f2.8 for the price of both combined?

Drizzt321

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Re: Please explain the need for f2.8 zooms
« Reply #4 on: January 30, 2013, 07:19:26 PM »
When you say 1 stop better, are you just talking about sensor noise performance or AF sensor performance?

My question is purely about sensor performance and why f2.8 will stay that important forever.

There is also another thing that you may not think of, is that lenses wide open generally don't perform their best.

... unless you're scraping together the money for a Canon 24-70L2

basically having a wide aperture available is like a condom
its better to have it and not need it than to need it and not have it :P

Ok, thanks for the answer from a real world pro, so you're on the side that even f2.8 isn't really "fast" enough and it just happens so that the fastest zooms available are f2.8. So if I understand you correctly you'd rather go with a Tamron f2.8 + a faster prime like the Sigma 35mm than a Canon 24-70/f2.8 for the price of both combined?

Well, even the Canon 24-70 v2 performs better stopped down. I never said that wide-open you can't get a lens that performs awesome. But if you stop down the Canon 24-70 v2 it gets even better.

That said, what lens(es) you chose often boils down to shooting styles, convenience (a high quality 24-70 is a lot easier to go 24, then 35, then 50 than changing primes), and can it get you what you want. Is it the best tool for the job, for what your budget can afford, and for how and what you are shooting.

Personally, while I wouldn't quite call myself a shooting pro, but I am shooting the residency for a small dance group, and while I'm renting the Tamron 24-70 for the next performance in a week, and probably buying that lens in the next 3-4 months. Not quite the weight of wickedwombat, or a couple of the other forum members, but I always seem to shoot in low or crazy lighting and I've found fast primes or f/2.8 zoom is practically a necessity. If you're shooting in decent lighting, or a studio or something, then ask if you really need a f/2.8 zoom. For me, I'm not shooting in those environments, so I've said yes, I do need a f/2.8 zoom (and the 70-200 some day, *sigh*).

Do you find yourself wide open all the time even as the ISO climbs higher and higher? Or are you comfortable going with a slower shutter and/or higher ISO and find an f/4 zoom is fine for you?
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Chris Geiger

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Re: Please explain the need for f2.8 zooms
« Reply #5 on: January 30, 2013, 07:22:27 PM »
I normally shoot rings at around f11 and group shots at f4-f5.6 but the rest of the time I am normally at f2.8. I also have a couple primes that I use from time to time but most of my work is with the 24-70 and 70-200 f2.8 lenses. With the 5DIII I have plenty of ISO to shot at f4 most of the time, but I prefer the look at 2.8. I really wish I could get a 35-85 1.4 zoom. I'd pay some really big bucks for a lens like that.

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Re: Please explain the need for f2.8 zooms
« Reply #6 on: January 30, 2013, 07:27:19 PM »
From a sports perspective.

I own a Canon 16-35 f/2.8, 24-70 2.8, 70-200 MkII (FINALY sold my MK I), 200 f/2 and 400 f/2.8 MkII. Why? I need to keep a shutter speed in excess of 1/500 (pref 1/1000+) to stop action. Most of the areas I work in DOF is not an issue as much as stopping motion and making sure I get the shot hence the reason for "Fast glass". I don't use the 24-70 much in all honesty BUT it does come in VERY handy after the fact.

Example: Shot with a 70-200 f/2.8 MKI
1/640 f/5.6 ISO 200 with a circular polarizer. I have the ability to open up and get more light if I need if clouds come in or the sun starts to set.

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Re: Please explain the need for f2.8 zooms
« Reply #6 on: January 30, 2013, 07:27:19 PM »

wickidwombat

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Re: Please explain the need for f2.8 zooms
« Reply #7 on: January 30, 2013, 07:30:37 PM »
When you say 1 stop better, are you just talking about sensor noise performance or AF sensor performance?

My question is purely about sensor performance and why f2.8 will stay that important forever.

There is also another thing that you may not think of, is that lenses wide open generally don't perform their best.

... unless you're scraping together the money for a Canon 24-70L2

basically having a wide aperture available is like a condom
its better to have it and not need it than to need it and not have it :P

Ok, thanks for the answer from a real world pro, so you're on the side that even f2.8 isn't really "fast" enough and it just happens so that the fastest zooms available are f2.8. So if I understand you correctly you'd rather go with a Tamron f2.8 + a faster prime like the Sigma 35mm than a Canon 24-70/f2.8 for the price of both combined?

only a part time pro ;)
unfortunately have to work a real job too :(

well I would happily pay $10,000 if canon made a 35-85 f2L IS that was razor sharp wide open
It would almost NEVER leave my 5Dmk3 and I could sell most of my primes
typically i'll shoot my 1.4 primes at f2 anyway as very often DoF at 1.4 is too thin however saying that if shooting an event in very low light with no flash even at iso 12800 i'll still be at f1.4 but really at those high iso
any sharpness differences between apertures are completely negated by the noise and loss of DR. In these situations there would be a real benefit of having f1.2 lenses

as for the tamron well I've had bad tamron encounters in the past so i'm really gun shy about this lens and have a somewhat prejudiced opinion which isnt helped when people report front elements falling out

Personally I think the 24-105L and say a sigma 35 f1.4 would be a more reliable combo
the 24-105L with some flash is a superb lens tough and very versitile and when f4 aint enough then swap over to the 35. If f4 isnt enough it doent take too much more light loss to make f2.8 not enough.
a neat trick with event photography is use a slower shutter speed to balance the ambient while keeping a decent iso like 1600 or even 3200 and using second curtain flash to freeze the subject these sort of techniques work great with f4 lenses (the IS on the lens helps reduce camera shake of the background and ambient while the flash takes care of the exposure and freezing the people. (look up dragging the shutter on google)

not to mention its basically impossible to take a good shot of half a dozen people at f1.4 either as only 1 person will have their nose in focus.

As with everything in photography the key is having a good understanding of the gear you are using, know its limits and work witin those limits. its only once you go beyond those limits that things get ugly

My wife however doesnt like shooting primes and so she prefers to use the 24-70L f2.8 mk1 over the primes

we are patiently waiting for the 24-70 f2.8L IS if it ever shows up or perhaps a sigma version to try out if that turns up
« Last Edit: January 30, 2013, 07:34:19 PM by wickidwombat »
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Marsu42

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Re: Please explain the need for f2.8 zooms
« Reply #8 on: January 30, 2013, 07:44:55 PM »
as for the tamron well I've had bad tamron encounters in the past so i'm really gun shy about this lens and have a somewhat prejudiced opinion which isnt helped when people report front elements falling out
I understand that and nearly forgot about the tamron until another CR wedding photog tested it and uses it as his wedding lens: http://www.canonrumors.com/forum/index.php?topic=11251.0

The thing to know about the 6D, is it's not really considered a 'professional' camera as such.
... said photog now uses a 6d and praises it over his 5d2, sure a 5d3 is better (at €1000 more...) but the way I see it either the 5d2 and 6d are "professional" or neither is - except for the fact that the "budget" €2000 6d is only valid for cps silver in Europe, thanks, Canon.

Personally I think the 24-105L and say a sigma 35 f1.4 would be a more reliable combo
the 24-105L with some flash is a superb lens tough and very versitile and when f4 aint enough then swap over to the 35. If f4 isnt enough it doent take too much more light loss to make f2.8 not enough.
That's basically what I figured, too - but I don't have enough experience yet to be sure of that reasoning considering the very strong "everyone needs f2.8 zooms" opinions.

a neat trick with event photography is use a slower shutter speed to balance the ambient while keeping a decent iso
Thanks a lot for this and the other hints, it's just a pity the Canon cameras have such a slow x-sync (6d: 1/180s...), but I really have to test 2nd curtain sync more to get a feel how much it can make a bit of motion blur "snappier" and at what export resolution.

wickidwombat

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Re: Please explain the need for f2.8 zooms
« Reply #9 on: January 30, 2013, 07:58:00 PM »
Thanks a lot for this and the other hints, it's just a pity the Canon cameras have such a slow x-sync (6d: 1/180s...), but I really have to test 2nd curtain sync more to get a feel how much it can make a bit of motion blur "snappier" and at what export resolution.

x-sync is irrelevent when dragging the shutter since you are shooting at 1/10th second or so
2nd curtain sync basically fires the flash at the back of the exposure rather than the beginning
and so freezes the subject over the top of any blur that might have occured from movement
its a cool technique for dancing etc since it captures the motion in a more natural way than 1st curtain would
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Drizzt321

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Re: Please explain the need for f2.8 zooms
« Reply #10 on: January 30, 2013, 07:58:52 PM »
as for the tamron well I've had bad tamron encounters in the past so i'm really gun shy about this lens and have a somewhat prejudiced opinion which isnt helped when people report front elements falling out
I understand that and nearly forgot about the tamron until another CR wedding photog tested it and uses it as his wedding lens: http://www.canonrumors.com/forum/index.php?topic=11251.0

The thing to know about the 6D, is it's not really considered a 'professional' camera as such.
... said photog now uses a 6d and praises it over his 5d2, sure a 5d3 is better (at €1000 more...) but the way I see it either the 5d2 and 6d are "professional" or neither is - except for the fact that the "budget" €2000 6d is only valid for cps silver in Europe, thanks, Canon.

Personally I think the 24-105L and say a sigma 35 f1.4 would be a more reliable combo
the 24-105L with some flash is a superb lens tough and very versitile and when f4 aint enough then swap over to the 35. If f4 isnt enough it doent take too much more light loss to make f2.8 not enough.
That's basically what I figured, too - but I don't have enough experience yet to be sure of that reasoning considering the very strong "everyone needs f2.8 zooms" opinions.

a neat trick with event photography is use a slower shutter speed to balance the ambient while keeping a decent iso
Thanks a lot for this and the other hints, it's just a pity the Canon cameras have such a slow x-sync (6d: 1/180s...), but I really have to test 2nd curtain sync more to get a feel how much it can make a bit of motion blur "snappier" and at what export resolution.

I'll second that the Tamron 24-70 f/2.8 VC is quite good. Maybe not quite up to the Canon 24-70 v2 in terms of sharpness and most build quality, but I can say from experience the build quality is definitely up there, and even wide open at ISO 6400 it was giving me quite good photos. Lighting for me was just horrendous though, probably worse than pretty much any wedding.
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robbymack

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Re: Please explain the need for f2.8 zooms
« Reply #11 on: January 30, 2013, 08:07:35 PM »
It's all a trade off. Some like to shoot wide open with no flash and sacrifice dof, others like to shoot stopped down and add flash to maintain dof. Just comes down to preference. The f2.8 zooms will give you better af performance on some bodies so that is why they like them, plus the added versatility of a zoom vs several primes.

Marsu42

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Re: Please explain the need for f2.8 zooms
« Reply #12 on: January 30, 2013, 08:14:29 PM »
x-sync is irrelevent when dragging the shutter since you are shooting at 1/10th second or so

Wow, I really have to try that - but 1/10s does result in shots with a large motion trail that are rather "artistic", doesn't it? Or you could even pull a sample shot out of your stack :-) ?

I thought more of a 1/60s as the lower limit (and conveniently settable in the camera fw), and the upper x-sync limit with 2nd curtain was meant if for fast motion 1/500s+ would be more appropriate, but a lower shutter speed captures more ambient/background light at acceptable iso.

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Re: Please explain the need for f2.8 zooms
« Reply #12 on: January 30, 2013, 08:14:29 PM »

RS2021

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Re: Please explain the need for f2.8 zooms
« Reply #13 on: January 30, 2013, 08:19:05 PM »
The standard lens requirement for shooting events/weddings seem to be a combination of 24-70/28 and 70-200/2.8, I read both are nailed to a pro's camera 90% of the time (though I have problems doing the maths :-))

I disagree with your basic presmise that  24-70 and 70-200 are "nailed" to wedding photographer's SLR's...and are "must-have" lenses. This is simply not accurate.

One wedding photographer I know uses his crop body and just two EF-S lenses and has a bag full of speedlights and radio gear ...he looks through my L lenses and smirks... "so, more toys I see?"  Another is an old timer who can pick his L-lenses from his oversized bag, but what sticks out in my mind is not his lens collection...but what he said about the amateurish need for razor thin DOF of f/1.2 on every occation...to paraphrase:

"You want a DOF where the bride appears to stand out amongst her guests, not so shallow a DOF that she apears to stand alone at her own party; it would be rather sad and a terrible waste of effort to have invited all those people!" (P.S. This gentleman also uses for the bride's portraits a softfocus prime 135 f/2.8!!!)

So it is almost a cliché to say that wedding photographers "must have" 24-70 f/2.8 or 70-200 IS II.  In fact, f/4 or higher would serve better at many moments.  For portraits and "beauty shots" probably faster lenses ranging in f/1.2 to f/2.8 work best, but a wedding is more than just portraits.

Many wedding photographers worth their salt and established in their business would have several speedlites well placed and programmed ahead of time across the hall and will also want some background DOF so it doesn't look like the couple is on their own. :)

Just my 2 cents.
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Don Haines

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Re: Please explain the need for f2.8 zooms
« Reply #14 on: January 30, 2013, 08:23:19 PM »
I thought that 2.8 was important for using the high precision cross type auto focus sensors.... Better and more accurate focus at 2.8, then the pics shot at the aperture of choice... Correct me if I am wrong, but I thought that this was how the autofocus operates....
« Last Edit: January 30, 2013, 10:20:17 PM by Don Haines »
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Re: Please explain the need for f2.8 zooms
« Reply #14 on: January 30, 2013, 08:23:19 PM »