It is interesting...

[gryphonslair99]

People don't spend thousands of dollars on f/1.2 lenses to shoot them at f/8. The blanket recommendation to not shoot wide open is lazy advice as a replacement for actually learning how to handle a shallow depth of field.

Lenses have limitations, but that doesn't mean that certain settings are off limits, just means you need to expect limitations.

Well I have spent thousands of dollars on and 85mm f1.2L and rarely shoot it at f1.2. The DOF is usually shallower than I want for the subject I am shooting. However if I shoot that same 85mm f1.2L at say f1.8 I have often increased my DOF to where I want it and I already know that it is going to be sharper at f1.8 than my 85mm f1.8 I bought for sports and action shots at f1.8.

You spent thousands of dollars on the Canon 85mm f/1.2 L to not shoot it close to wide open?

That's strange. I wouldn't shell out any amount of money for an 85 f/1.2L. It's simply not worth it with the Sigma offering of the 85mm f/1.4

f1.8 is pretty close to wide open. I shoot for the DOF that I want/need in the composition. If it is wide open then that is what I shoot. If it is not then I stop down. But I can't get that razor thin DOF with an f2.8 or even a f1.8 lens. Kind of like when I was a boy growing up on the farm. Asked my grandad one time why he always wore long sleeve shirts whether it was the during the cold of January or the Heat of July. He looked at me and smiled a bit and said, "boy, I can always roll these long sleeves up and make em short, but no matter how much you try, you can't make them short sleeves of yours long ones."

Me, I'm from the camp of using the aperture that best suits the composition whether it is wide open or stopped down a bit.

[TPF Sponsor]

[Garbz]

that you hear not to shoot "wide open" because of DOF issues and soft focus problems, but then you'll pay $$$$$ for a lens with a max aperture of f/2.8.

Kinda like buying Ferrari and then being told not to drive over 100mph because of wind noise...

Owell.

All lenses are bad at their widest open aperture except for a few notable exceptions. But what you're missing is that value changes with the lens.

My 18-70mm f/3.5-4.5 is at 50mm much sharper with an aperture of f/5.6 than f/4
My 50mm f/1.8 is much sharper at f/2.8 than the lens above at f/4. But it's quite bad at f/1.8
My 50mm f/1.2 is much sharper at f/2 than the lens above at f/2.8, but it's quite bad at f/1.2

Even if going for pure quality you have something to gain with pro grade glass offering wide apertures.

[gizmo69]

When i worked on my theme traitement hémorroïdes, I wondered the same thing in terms of aperture. I think it depends on the quality you want to give to you photo, and on your equipement. Just try tom ake different settings, you will success

[DiskoJoe]

Whats the point of buying a lenses with a big aperture if you dont use it? I love the depth of field created by leaving my lens wide open. I do this a lot for portraits and wedding photography.

[Vtec44]

I vary the aperture depending on what I'm doing, so a fast lens gives me more flexibility to do so in various lighting conditions and styles. Plus expensive lens = instant pro photog!!

[HughGuessWho]

Ok, I'm a nube here at TPF, but felt like I needed to jump in on this one. Someone please correct me if I'm wrong, but, as I see it a "faster" lens (1.4 or 2.8) gives you more glass than, say a f/3.5-5.6 lens. Therefore, even if you are stopped down, you are still getting more light to the sensor, allowing you to shoot in lower light levels, for example.

[KenC]

If you really wanted to drive 100 mph, you would let wind noise stop you?

[Garbz]

Ok, I'm a nube here at TPF, but felt like I needed to jump in on this one. Someone please correct me if I'm wrong, but, as I see it a "faster" lens (1.4 or 2.8) gives you more glass than, say a f/3.5-5.6 lens. Therefore, even if you are stopped down, you are still getting more light to the sensor, allowing you to shoot in lower light levels, for example.

Nope. The aperture is a ratio between the iris and the focal length of the lens. If you take a 50mm f/1.2 and set it to f/1.8 it will let in the same amount of light as a 50mm f/1.8 shot wide open. The iris obscures the additional glass.

[HughGuessWho]

Ok, I'm a nube here at TPF, but felt like I needed to jump in on this one. Someone please correct me if I'm wrong, but, as I see it a "faster" lens (1.4 or 2.8) gives you more glass than, say a f/3.5-5.6 lens. Therefore, even if you are stopped down, you are still getting more light to the sensor, allowing you to shoot in lower light levels, for example.

Nope. The aperture is a ratio between the iris and the focal length of the lens. If you take a 50mm f/1.2 and set it to f/1.8 it will let in the same amount of light as a 50mm f/1.8 shot wide open. The iris obscures the additional glass.

Right, but I was speaking of something different. Being a nube, I wasnt too clear. Before the picture is taken, and you are in composing and focusing a shot, the iris is wide open, allowing more like to the sensor, thus allowing you to better see the image in the view finder or allowing the auto focus to operate in low light situations, whereas, say at f5.6, there may not be enough light for auto focus to function or for you to be able to see well enough to get a good manual focus. Then, of course, just as you "click the pic" the apeture stops down to the selected f-stop.
Am I close?

[MTVision]

Right, but I was speaking of something different. Being a nube, I wasnt too clear. Before the picture is taken, and you are in composing and focusing a shot, the iris is wide open, allowing more like to the sensor, thus allowing you to better see the image in the view finder or allowing the auto focus to operate in low light situations, whereas, say at f5.6, there may not be enough light for auto focus to function or for you to be able to see well enough to get a good manual focus. Then, of course, just as you "click the pic" the apeture stops down to the selected f-stop.
Am I close?

I don't think so. You choose the aperture, compose and focus - as far as I know the aperture stays the same. It doesn't open up so you can focus. If you choose f/5.6 - you focus/compose the picture with the aperture at f/5.6. It doesn't open wide and then stop down when you take the picture.

[Garbz]

Actually the self proclaimed noob is right. When you choose your aperture you focus and compose the image with the lens wide open. The lens stops down when you take the photo. This is precisely the reason many cameras have a "preview" button which closes the aperture blades to the selected setting so you can sus out your depth of field.

HughGuessWho you're unfortunately missing one more piece of the puzzle. Making a ultra wide aperture lens is difficult and quite often these lenses perform very poorly open wide. Certainly lenses like the 85mm f/1.4 are less sharp at f/1.4 than say my kit lens at it's widest aperture f/3.5

This actually causes problems for the AF unit too. So it's not a simple given that these lenses will focus better in low light, though as you correctly asserted most of them do.

[DiskoJoe]

Actually the self proclaimed noob is right. When you choose your aperture you focus and compose the image with the lens wide open. The lens stops down when you take the photo. This is precisely the reason many cameras have a "preview" button which closes the aperture blades to the selected setting so you can sus out your depth of field.

HughGuessWho you're unfortunately missing one more piece of the puzzle. Making a ultra wide aperture lens is difficult and quite often these lenses perform very poorly open wide. Certainly lenses like the 85mm f/1.4 are less sharp at f/1.4 than say my kit lens at it's widest aperture f/3.5

This actually causes problems for the AF unit too. So it's not a simple given that these lenses will focus better in low light, though as you correctly asserted most of them do.

The 85mm at f1.4 would not necessarily be less sharp then your kit at f3.5. A lot of this depends of lens quality. So this could go either way depending on what lenses you are comparing.

[analog.universe]

Actually the self proclaimed noob is right. When you choose your aperture you focus and compose the image with the lens wide open. The lens stops down when you take the photo. This is precisely the reason many cameras have a "preview" button which closes the aperture blades to the selected setting so you can sus out your depth of field.

HughGuessWho you're unfortunately missing one more piece of the puzzle. Making a ultra wide aperture lens is difficult and quite often these lenses perform very poorly open wide. Certainly lenses like the 85mm f/1.4 are less sharp at f/1.4 than say my kit lens at it's widest aperture f/3.5

This actually causes problems for the AF unit too. So it's not a simple given that these lenses will focus better in low light, though as you correctly asserted most of them do.

The 85mm at f1.4 would not necessarily be less sharp then your kit at f3.5. A lot of this depends of lens quality. So this could go either way depending on what lenses you are comparing.

This^

My 50mm wide open at 2.0 is sharper than my 85mm stopped down any amount.

[HughGuessWho]

Actually the self proclaimed noob is right. When you choose your aperture you focus and compose the image with the lens wide open. The lens stops down when you take the photo. This is precisely the reason many cameras have a "preview" button which closes the aperture blades to the selected setting so you can sus out your depth of field.

HughGuessWho you're unfortunately missing one more piece of the puzzle. Making a ultra wide aperture lens is difficult and quite often these lenses perform very poorly open wide. Certainly lenses like the 85mm f/1.4 are less sharp at f/1.4 than say my kit lens at it's widest aperture f/3.5

This actually causes problems for the AF unit too. So it's not a simple given that these lenses will focus better in low light, though as you correctly asserted most of them do.

Before I saw DiskoJoe’s response, in my desperate attempt to defend my case, I stopped by my local camera shot and spoke with my favorite camera tech. I must say, at first I was a bit embarrassed when he laughed at my question, BUT his response made perfect sense.
“Look through your viewfinder at wide open aperture, then, stop all the way down. Did your view get any darker?” Question answered.
So, the moral of the story would be, there IS or CAN BE a benefit to having a fast lens, even if you don’t shoot wide open.

[Kerbouchard]

Right, but I was speaking of something different. Being a nube, I wasnt too clear. Before the picture is taken, and you are in composing and focusing a shot, the iris is wide open, allowing more like to the sensor, thus allowing you to better see the image in the view finder or allowing the auto focus to operate in low light situations, whereas, say at f5.6, there may not be enough light for auto focus to function or for you to be able to see well enough to get a good manual focus. Then, of course, just as you "click the pic" the apeture stops down to the selected f-stop.
Am I close?

I don't think so. You choose the aperture, compose and focus - as far as I know the aperture stays the same. It doesn't open up so you can focus. If you choose f/5.6 - you focus/compose the picture with the aperture at f/5.6. It doesn't open wide and then stop down when you take the picture.

The lens is wide open until your shutter button is pressed.