fast glass

[Mitch1640]

honestly how often do you owners of the 70-200 f2.8 actually use it wide open? or other fast glass, im just using the 70-200 as an example. people always talk about how important fast glass is, but i rarely hear of people using them wide open, we all know it isnt sharpest there anyways.

i just sort of feel that fast glass is a little over emphasized.

 

[JerryPH]

Are you talking about the Canon or the Nikon 70-200?

I have the Nikon version of the 70-200 and if I do not use it wide open, it is very close to wide open. About the only time it is not at F/2.8 is when doing portrait photography and I have 600 W/s of Profoto lights blasting the subject. Then it is up around F/11-F/16 @ 1/250th.

 

[tsaraleksi]

I shoot with my 2.8 lenses wide open a lot of the time, really any time that I'm in bad light. Unless I particularly need a lot of depth (groups or something) I will go ahead and open the lenses up, because on the Canon Ls (and their counterpart Nikons) the quality wide-open is usually really good, to the point that I'd rather do that than up the ISO.

Like Jerry the main time that I stop way down with the 70-200 is when doing portraits. I'm much more likely to stop down a shorter lens, actually.

 

[rufus5150]

By and large, an f/2.8 lens will look sharper at f/4 than an f/4 lens. That, to me at least, is my primary motivation going fast, but it's nice to have the option to shoot wide open (frankly, the bokeh at my 50mm at f/1.4-1.8 is silky, silky smooth).

 

[JerryPH]

By and large, an f/2.8 lens will look sharper at f/4 than an f/4 lens. That, to me at least, is my primary motivation going fast

I would have to agree. All lenses that I know of are not at their sharpest at the widest aperture. Stop down 1-2 stops and big things start to happen in the sharpness department.

but it's nice to have the option to shoot wide open (frankly, the bokeh at my 50mm at f/1.4-1.8 is silky, silky smooth).

For sure... but I like the bokeh of fast glass that is above 50mm. Way nicer bokeh at 200mm and F/2.8. Compared to 50mm F/1.4 which would still fall under the cream machine of all lenses, the 85mm F/1.4 (not counting a Nottelux F/1.0... lol).

The first time I played with my 70-200 it was at F/4 and "creamier" than when compared to the F/1.8 of the 50mm. That is to be expected, though as that is how bokeh works.

A couple examples...

F/4 @ 95mm on the 70-200 lens:

50mm @ F/1.8 on the 50mm Nikon "plastic fantastic":

85mm @ F/1.4 on the 85mm Nikkor "cream machine":

 

[Montana]

Fast glass also has "side benefits". Like a brighter viewfinder and depending on the body/lens, faster autofocus abilities.

 

[Phranquey]

I shoot with mine wide open quite often. And, Montana is correct...the f/2.8's are usually the top end pieces of glass, which also yields better build quality, the better AF systems, better clarity glass, best glass coatings, etc.

As far as "over emphasized", if you mean over rated, then no, they are not. They may be a little over priced, but the producers are going to make you pay for the best.

 

[elemental]

Another "side benefit" is often better build quality, which can (apparently) make a big difference when you're using it day in and day out on critical projects.

I use every lens I have wide open at least some of the time (though I don't have a 70-200 f/2.8, since I rarely shoot longer than 50mm).

 

[Overread]

Also fast glass will generally take a teleconverter well also - my 70-200mm f2.8 gets used with a 1.4 teleconverter on a regular basis (And is then only an f4 lens). Even with a 2* teleconverter its only an f5.6 lens - still very usable (in good lighting when stopped down to f8 )

My macro lenses are hardly ever used wide open and are often stopped down to f13 or smaller- but the f2.8 view through the viewfinder is most certainly needed on those lense to compose and focus shots - if you were to get smaller the view would be so dark as to be impossible to use (or at least requireing a bright external light source to facilitate focusing

 

[Battou]

I would have to agree. All lenses that I know of are not at their sharpest at the widest aperture. Stop down 1-2 stops and big things start to happen in the sharpness department.

There is the bulk of the emphasis to fast lenses. If you are toating around a 70-200 2.8L wile your buddy is toating around a 200mm 4.0L and you both take a shot at F/4 the difference in outcome is obvious. Wile you are shooting at the same aperture at the same shutter speed, you have your lens stopped down a touch wile your buddy is shooting wide open.

 

[JerryPH]

Wile you are shooting at the same aperture at the same shutter speed, you have your lens stopped down a touch wile your buddy is shooting wide open.

That is another way of saying exactly the same thing.

 

[Battou]

That is another way of saying exactly the same thing.

That was the point.

I was not calling you out, just reiterating what you said before people go into a bokeh tangent because it was the reply the OP sought.

 

[usayit]

All the points above are true... Faster aperture glass is an advantage and exceptions; I much prefer my "slower" 24-105 f/4L over my Tamron 35-105 f/2.8 in all points except max aperture.

One main disadvantage that hasn't been mentioned is the increase weight and size of faster glass.

 

[Battou]

One main disadvantage that hasn't been mentioned is the increase weight and size of faster glass.

Good point, I had not even thought of that point. Ironically I happen to have a decent example image. It's not perfect but....

Below are two Canon 50mm lenses of the same vintage, one a 1.8 the other a 1.4.

That is just a 1.8 and 1.4, just imagine the difference between a 2.8 and a 4.0 70-200.

 

[Phranquey]

One main disadvantage that hasn't been mentioned is the increase weight and size of faster glass.

I don't see this as a disadvantage. When on a tripod, any vibrations tend to settle out faster. Yes, when hand-held, larger glass can fatigue the arms faster, but after some practice, you learn they are less susceptable to "jitters" due to their greater mass.