Why is it that the 2.8 zoom is synonymous with the phrase "fast glass"?

<p>I rarely write about gear, but sometimes there is a reason to. The following is a little rant about the problem I have with f/2.8 midrange zooms being called "fast glass".</p>

<p>For some reason, everytime someone expresses interest in "fast glass" or whatever, someone seems to suggest the person get a wide-to-short-tele f/2.8 lens. A newbie complains that his 4-5.6 zoom doesn't deliver in low light or that it has too much DOF for portraits. And overwhelmingly, one or more people always recommend a $1500 24-70/2.8 "pro zoom" lens as the answer. The newbie then replies "Oh, that's too expensive. I guess I will have to stick with my 4-5.6 lens for a while." Sometimes, a person like me will then jump in and suggest an f/1.8 prime, but it seems that most people don't want to give up the zoom cabability, so they decide against the prime. The strange thing is that the person who asked the question often ends up falling pray to marketing hype, and goes out and ends up spending $500 or more on something like a 24-120 that is still f/5.6 at the long end and still did not solve their issue! There's something really wrong with that picture. They could have gotten a 50/1.8 for like $100, and had all the aperture speed they ever wanted!</p>

<p>The truth of the matter is that an f/2.8 24-70mm is not a fast lens. Yes, it's a fast zoom. Yes, it's pretty much the widest aperture available in a zoom unless you go 4/3 Olympus, who has f/2 zooms. yes, it's 2 stops faster than a 5.6 aperture zoom. But as far as ALL lenses go, 2.8 is NOT fast glass! But people often treat it like it is the ultimate aperture to lust over, as if there is something magical about that f/2.8 number. And then they discount the primes that are 1.5 to 2 stops faster and much more cost effective!</p>

<p>Personally, I've found that if anything, f/2 is far closer to the "magic aperture" for moderate to low avialable light photography. The f/2.8 zoom may be fast as far as zooms are concerend, but for primes in the same range, f/2.8 is average. I'd take the Canon f/1.2 50mm over a 2.8 24-70mm zoom any day. Even an f/1.8 85mm is preferable to a 2.8 zoom for low-light work in my opinion.</p>

<p>It's been this way ever since I can remember: even back in 1997, the average amateur was raving about (or maybe more like dreaming about owning) the 28-70/2.8 Canon and the 35-70/2.8 Nikkor, but they weren't looking seriously at the faster primes!</p>

<p>I think many newbies are in for a rude awakening when they buy an f/2.8 zoom on impulse. Later on, they will realize that it is not really the best tool for low-light work as the internet articles, blog postings, and mainstream photo magazine articles would like people to believe.</p>

<p>Newbies are <em><strong>always</strong> </em> in for rude awakenings as they learn what complex matters lie ahead.....</p>

<p>Zooms are the most common lenses, and 2.8 is in general the fastest (non Olympus) zoom. Thus, 2.8 is fast.</p>

<p>f 2.8 is not *bad* if the lens is sharp at 2.8. A lot of times f1.4 lenses are not amazingly good at 1.4, and you are better off at a higher ISO. That said, I would love a 35mm 1.4.</p>

 

<p>Of course, <a href="http://en.wikipedia.org/wiki/TANSTAAFL">TANSTAAFL</a> , and those bargain 50mm f/1.8 lenses aren't the panacea that some posters often to make them out to be. In particular, they tend to focus slowly, which can be a problem for some situations. Don't get me wrong, I think my 50mm f/1.8 is a huge value and I'm in the market for a couple of fast primes in the normal/WA and medium telephoto ranges, but a med-WA to med-Tele f/2.8 zoom with a fast focus motor is still a very sweet spot for <strong>a lot</strong> of shooting (and not that expensive, if you're willing to consider the third-party offerings).</p>

<p>It’s also worth noting that faster than f/2.8 outside of the normal to short telephoto range

starts to get really expensive, really quick. Heck, even f/2.8 gets really expensive really quick

— priced even a 300 mm f/2.8 lately, let alone a 400 mm f/2.8? And if you want wider than 28 mm plus faster than f/2.8,

you’ve got exactly one option from Canon: the $1700 24 mm f/1.4.</p>

 

<p>I think it’s entirely reasonable to call f/2.8 “fast,” even if it’s not the

fastest of the fast. f/5.6 is slow. f/4 is moderate. f/2.8 is fast. f/1.4 is super-fast. And f/0.9 is ludicrous

speed…</p>

 

<p>Cheers,</p>

 

<p>b&</p>

<p>And then there's the sticky issue of explaining to newbies how depth of field and corner sharpness is affected by really fast glass, and that shooting at a really wide apertures may not be the right answer for the kind of photos they want to make...</p>

<p>I can't imagine why you would have a problem with people saying a 2.8 zoom is "fast glass". As others have stated here, 2.8 is fast for a zoom. Why have a 2.8 zoom in the first place, especially an expensive one? Because they allow you to take good photos and you don't have to keep switching lenses. Ask most wedding photographers and event shooters what they use the most and you discover that a wide fast zoom and fast medium zoom are on their cameras 90 percent of the time. Fast prime lenses are great and some are inexpensive, ie the Nikon and Canon 50mm 1.8. Use what you feel comfortable with and what you can afford and let others do the same. </p>

<p>In the "battle" between zooms and primes, zooms have clearly won. Similarly the competition for the fastest prime was pretty much over by 1964, when we saw f/2.8 lenses for 4x5 cameras (Linhof) the size of bread plates and f/0.95 Canon lenses (with all the image quality of a coke bottle).</p>

<p>Who cares if newbies or oldbies (in lieu of a better term?) describe f/2.8 zooms as "fast". In fact, they are fast compared to lesser quality zoom lenses. More important, they are designed better in other ways as well - constant aperture, superior build quality and better optical quality overall. In short, the major manufacturers tend to pull out the stops (pun intended) to make the best possible lens, which happens to have an f/2.8 aperture. No surprise that they cost 3x as much as comparable, marginally slower lenses. Less surprising is that third-party manufactures can offer f/2.8 zooms at half the price. Do ya' think something got left out?</p>

<p>A better term might be "pro" lenses - an assignation which rankles those who can't afford them and excites those who collect them. I'm kinda' neutral over nomenclature - they work for me because they replace a bag full of prime lenses and the need to swap them at inconvenient times, without any significant penalty in terms of image quality.</p>

<p>I should think that an old timer like VAL would have better things to complain about (unless VAL is an envious newbie in disguise).</p>

<p>Before the advent of dust-sensitive digital sensors, I seldom gave a thought to dropping to one knee (safety precaution against a lens that decides to commit suicide by taking a leap), digging into my bag, and swapping a lens in to suit me. I did that exactly once in the field with my 5D, and immediately afterwards thought 'doh'!<br>

Zooms solve a lot of problems for me in that respect. I usually wander about with the 17-40L on the 5D and the 24-70L on the 50D to cover as much of the bases as I can at the ranges I like to shoot within.<br>

Would I prefer to wander with my 135L? Certainly. But it sometimes seems too restrictive, and it's really annoying to me to find something I want to shoot and can't foot-zoom to get it in (falling off a cliff into the ocean is not a preferred option).</p>

<p>I'm not a fan of "fast" glass, as I cannot afford it. I think if you really want good optics that are taking care of business below f/4, then you need to be prepared to spend some money. My applications don't really call for this. </p>

<p>As soon as I see a "do everything" type of ad, I am automatically skeptical. It doesn't bother me if other people like other equipment. They like what they like. Really, more of my interest lies in an f/8 to f/16 range anyway.</p>

<p>You can try to educate someone but there is no law saying they have to listen to you. I have no midrange f2.8 zooms but I have a 28, 50, and 85 all f1.4. They suit me better but obviously some people need the zoom.</p>

<p>Context! As you yourself noted in your post an f2.8 throughout the whole zoom range is fast....for a zoom. It's also fat, long, heavy and expensive! Even as we have moved into the digital age equipment selection is still a trade off. What do you value most? What can you live with....or not live without? Put into that mix your budget and occupation, is photography your hobby or income stream, stir well and come up with answers as to how or if to lay out your hard earned cash.</p>

<p>While not everything is relative, most things are. You yourself have given the context for calling these "fast". We're all purists about something or other, but you probably need to take a deep breath and relax a little since the 'fast' lenses you mention were only in that position briefly and insecurely anyhow. I would never consider an f/2 lens to be fast--that was what came with my early SLR cameras. <em>Fast</em> was a Nikkor 55mm f/1.2. Maybe, although reluctantly, I'd accept an f/1.4 as "fast."</p>

<p>During the 1930s many rangefinder and folder cameras with f/2.8 or even f/3.5 lenses were described in advertisements as "fast"--and so they were, compared to the f/7.7 and such 'normal' cameras of their day.</p>

<p>As an old Greek poem from antiquity put it</p>

<blockquote>

<p>Truth alone does not exist,<br>

Seek beauty if thou desirest peace.</p>

</blockquote>

<p>Speaking of context: Once you get into medium format, f/2.8 is quite fast even for a prime. I found that f/1.9 was pretty much the fastest prime available in the Mamiya system. This is because the lenses are bigger and use more glass than those for 35mm. Now, I still haven't shot 4x5 or anything really big, but I've noticed that 5.6 is a common maximum aperture once one gets into large format.</p>

<p>The other day, I opened up the latest issue of Pop Photo, and they were testing an f/0.95 Leica lens for the M series! Price? $10,000.</p>

<p><strong><em>I rarely write about gear, but sometimes there is a reason to. The following is a little rant about the problem I have with f/2.8 midrange zooms being called "fast glass".</em></strong><br>

<strong><em>For some reason, everytime someone expresses interest in "fast glass" or whatever, someone seems to suggest the person get a wide-to-short-tele f/2.8 lens. </em></strong></p>

<p>For those of us who toil(ed) (I'm retired) as PJs, f/2.8 was classic, the lenses magnificent and very "fast" when compared to other zoom lenses. Today, anyhting can be "fast what with ISO4000 being a dial-in. <br>

"Fast" also meant "quality", "professional" if you would. My by now "ancient" (circa 1992) EOS "L" lenses, one a 28-70 the other the unflappable 70-200 "L" still are fast and capable as they were when I purchased them. <br>

In these days of dial-in high ISOs, "fast glass" is a near misnomer. <br>

<strong><em></em></strong><br>

<strong><em>A newbie complains that his 4-5.6 zoom doesn't deliver in low light(SNIP)</em> <em>They could have gotten a 50/1.8 for like $100, and had all the aperture speed they ever wanted!</em></strong></p>

<p>With my Olympus 4/3rds system, 50mm @f/1.8 only gives you 100mm @ f/1.8, still not enough range or speed for the types of shots most people without pro lenses ask for. <br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong>The truth of the matter is that an f/2.8 24-70mm is not a fast lens. Yes, it's a fast zoom. Yes, it's pretty much the widest aperture available in a zoom unless you go 4/3 Olympus, who has f/2 zooms. yes, it's 2 stops faster than a 5.6 aperture zoom.</strong></em></p>

<p>Your denial noted, an f/2.8 constant aperture is a <em>fast zoom</em>. even the f/3.5 constant aperture lenses of the eighties were "fast" for their time.<br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong>But as far as ALL lenses go, 2.8 is NOT fast glass! But people often treat it like it is the ultimate aperture to lust over, as if there is something magical about that f/2.8 number. And then they discount the primes that are 1.5 to 2 stops faster and much more cost effective!</strong></em><br>

<em><strong></strong></em></p>

<p>I see you've never hoisted a bag of primes plus flash plus a tripod on an all day mission? Those f/2.8 zooms you so denigrate? They saved photojournalism's buttocks, lightening the load for any PJs and now, "Hobbyists".<br>

F/2.8 zooms do more than 95% of all "Pro" lenses output. F/1.4,1.7,1.8 primes? Perhaps 2%? <br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong></strong></em><br>

<em><strong>Personally, I've found that if anything, f/2 is far closer to the "magic aperture" for moderate to low avialable light photography. </strong></em></p>

<p>Agreed, though part of the problem is the defintion of "low light" or more properly "Available light" photography. Available light photography can be done with any lens of any speed. All you neede is... light. What too many want in that genre of photography is low light lenses that will also....wait...wait; <em><strong>stop motion</strong></em>.<br>

My super-fast f/1:1.2 lens is not much of a "low-light" lens in f/1:1.0 light. Stopping motion in low light is sort of futile: babies, dancing partners, high school football lighting tax the capabilities of even f/2.8 lenses at nighttime. Hell, even a very cloudy day has shut down my EOS f/2.8 "L" lenses. Worse, I have tried my <em>50mm <strong>f/1.4</strong></em> lenses in low light and had them act like...f/5.6 lenses. <br>

As you note, f/2.8 lenses aren't that fast but in ordinary light, they are fast enough. Even if your zoom is f/2.8-f/3.5, in Av mode at f/2.8, your zoom becomes an f/2.8 throughout the zoom range.<br>

Long time ago, before the advent of ISO 4000, all we "old time" photographers performed "available light" photography with old, slow f/4.5 down to f/6.3 lenses: all it took was a little light, a sturdy tripod, knowledge of the process and no nutty notions like we could stop motion in available light, even with really fast glass like my f/1.2. None of us were crazy enough to beleive that shooting moving objects wouldn't produce blurry images.<br>

(SNIP) even my Canon S. S. C. f/1:1.2 prime sucks (blurry images) in some "low light" venues; ask me; I know it does.</p>

<p> </p>

<blockquote>

<p>I see you've never hoisted a bag of primes plus flash plus a tripod on an all day mission?</p>

</blockquote>

<p>Please do not be so quick to jump to that conclusion. I recently took the following with me on an all-day trip to New York:</p>

<p>EOS A2 with VG-10<br />EOS 1D<br />70-200/2.8 IS<br />50/1.8 II<br />85/1.8 USM<br />35/2<br />17-40/4<br />Mamiya 645 AF<br />80/2.8</p>

<p>It was not fun to carry. But I did not carry it for fun. I carried it because I needed it. And yes, I cheated by using some zooms. ;-) I can understand where you're coming from. I do a good bit of PJ stuff myself. I would not want to carry all that <a href="mailto:cr@p">cr@p</a> all the time.</p>

 

<blockquote>

<p>I should think that an old timer like VAL would have better things to complain about (unless VAL is an envious newbie in disguise).</p>

 

</blockquote>

<p>I'm not an old-timer, though I might as well be since I know a bunch of them and respect their approaches. Not exactly a newbie either though; I there is a good dozen years of photographic experience between me, myself, and I.</p>

<p>And yes, I do wish that the f/2, f/1.8, and f/1.8 35mm, 50mm, and 85mm were 1.4, 1.2, and 1.2 lenses respectively.</p>

<p>A good wide to mid tele f/2.8 zoom is reasonably fast, although it is going to be expensive. Of course, getting 3 f/1.8 primes to cover the same range (28/50/85) is going to cost the same or possibly more. Zooms are incredibly convenient, since you don't have to change lenses all the time, a nice feature if you have to work quickly. </p>

<p>Theres also a correlation between fast and quality, Fast zooms are usally made for more demandind purposes and are usally made of a higher optical quality than their slower counterparts. The pro catagory of lens always tend to be faster in both zoom and prime.</p>

<p>Right, f/2.8 isn't fast for available light work, but it's fast for a zoom. The use of primes requires planning, discipline, practice, etc. basically you need to know what you're doing and most people don't have the kind of patience required to be able to shoot with primes effectively. Personally I don't like the poor reach and aperture vs. size and weight ratio of the f/2.8 zooms, so I only have one, the 24-70, which I need for weddings, and then the rest of my lenses are fixed focal lengths.</p>

<p>VAL it all depends on what you shoot and your style. So how am I being so negatively being affected by these zooms? <br>

Nikon 70-200mm f/2.8 VR <br />Nikon 80-200mm f/2.8 <br />Tokina 28-70mm f/2.8 <br />Nikon 14-24mm f/2.8 <br /><br />Understand I did shoot primes they were to heavy bulky for most of my work and I had to carry 3-4 cameras as opposed 2-3 I now use. And for my work the 50mm was pretty much useless except as paper weight. 50mm for was so blah and a crappy portrait lens for my style. Personally I prefer my 70-200mm or my 14-28mm for portraits. <br /><br />Don't mistake personal style for fact, which is what you are doing now. <br />I do still use primes mainly my Tokina 300mm f2.8 and occasionally my Nikkor 85 f/2.<br>

As for defining a glass as fast, traditionally if it is f/2.8 it is considered fast, unless it is a very long lens like a 600mm f/4 in which case it is considered fast.</p>

<p>I do existing light inside dim nightclubs with my D80 and my neekon 2.8 70-200, iso maxed out and speed at 1/60 and get great pics that with some post turn out really incredible. then I also drop in a ZEISS 50/1.4 prime and I think the camera has better sensors than my eyes, my feet now become the zoom, not a big deal and Zeiss glass is much much much cleaner than all my other lenses and then some. my camera lives on manual, always, including focus and exposure and I never look at the meter, so the zeiss is just as usable at the autopilot enabled nikon lenses in my collection of 20+ assortment. "Fast" is just a relative reference as to how much light comes in thru the lens as the aperture becomes larger. also a term as to how quick your money will go on the lens..... rreally fast lens= really fast money spicket on yer wallet!</p>

<p>With a good digital SLR the need for fast glass for low light applications has diminished - My Canon 5DII is pretty good even at ISO 1600 - at least 2 stops better than film so as i used to like (and still own and love) F1.2 and F1.4 glass an F2.8 lens should be fine. The real issue for me is depth of field - a lens like my Canon 85 F1.2 has such a narrow depth of field that my F2.8 l series zooms (I have all 3) cannot match. That said I find that i use the zooms a lot more than I used to in the MF days. If you find F2 is the limit for low light then you are probably not shooting a modern full frame DSLR as both Canon and Nikon full frame bodies are very good even with an F4 lens in low light. I am a big fan of "fast glass" having spent 25 years shooting film but as someone stated above it really depends on the quality of the glass at maximum aperture. My wife shoots contax G2s and the 21mm, 28mm and 90mm lens for these cameras are all F2.8 does that make them slow? In terms of quality these three lenses (especially the 90mm) are better than my Canon F2.8L series zooms at any aperture. Indeed while not as fast as the Canon 85 f1.2 I would say that the Contax G 90 F2.8 is sharper and has much better contrast.<br>

The question is why do you need the size and weight of fast glass - for low light modern sensors are making it rather obsolete but for fast AF and shallow depth of field fast galss cannot be beaten. <br>

I shoot Fuji GX680 MF and the fastest glass you can get is F3.2 - does this make it slow. Well you need a tripod and static subjects (I usually shoot Velvia 50 at 40 ISO) but for DOF the Fuji 180 F3.2 is hard to beat - razor sharp, with a shallow DOF and Bokah to die for.<br>

The real issue is lens quality which is a balance of several factors, maximum aperture being just one of them.</p>

<p>Your final point on low light seems a bit off to me - I shoot amateur indoor ice hockey in arenas as dark as LV8. I only use F2.8 lenses (300 F2.8 and 70-200 f2.8) and have no problem. What lens would you suggest that I shoot 200 F2 or 135 F2 would seem to be my only options. I have and love the Canon 135 F2 (it is an amazing lens) but the 70-200 F2.8 l zoom is more useful as you can zoom as the play moves towards or away from you. a freind of mine who shoots for the local paper uses the same lens combinations when he shoots indoor hockey. This is probably one of the more demanding low light subjects as the light can be very bad in some old arenas and you need to freeze subject movement (tripods and IS do not help). If you shoot film (I don't like to go beyond ISO 400) then light is a problem but with digital F2.8 is more than enough.<br>

Perhaps you could expand on the ISO limits and situations where F2.8 is a major limiting factor. I assume that you are refering to modern DSLRs. Before you think I am a zoom bigot I only own 5 zoom lenses out of over 35 lenses (Canon FD 35-105 f3.5 and FD 80-200 F4L and canon EF 16-35 F2.8 II, 24-70 F2.8 and 70-200 F2.8) all of the rest are primes and only 13 are slower than F2.8 - of these slow lenses 11 are MF (seven are Fuji GX 680 lenses) and of the remaining 4 two are very long, one is macro leaving the old canon FD 17 F4 the only short slow lens that I own.</p>

<p>Philip,</p>

<p>Thanks for the balanced opinion!</p>

 

<blockquote>

<p>Perhaps you could expand on the ISO limits and situations where F2.8 is a major limiting factor. I assume that you are refering to modern DSLRs.</p>

 

</blockquote>

<p>Certainly. ISO 800 (older digital SLRs and 35mm film) and 1/80 second with or without fill flash, indoors away from window light, with incandescent or fluorescent lights, handheld with a moderate focal length (between 28mm and 85mm). Usually f/2 is needed.</p>

<p>Someday I'll upgrade to a 5DII, I swear. Someday! Then I'll be able to shoot at 1/180, f/2.8, and ISO 3200.</p>

<p>AL,</p>

<p>Wow, you shoot without a meter?! That takes some serious experience. I want to learn how to do that. How do you know what settings to use? Just by looking at the scene and metering with your eyes?</p>