2.8 compared to a 4.5

[RumDaddy]

2.8 Glass. MEANS YOULL SPEND 2.8 TIMES THE MONEY ON THE GLASS. :er:


AAA. I know the 2.8 is a faster glass. For you newbies who arnt a master photgraffer like myself. LOL! Fast glass means better images in lower light situations. I know not only is this type of glass needed for wedding photographers. Because of church restrictions and low light banquet halls. But Ive heard this theory is so strongly backed up that it I feel confident that it is worth spending the extra "2.8 money"

BBB. Experts correct me if Im wrong. But Im led to believe a 2.8 compared to a 4.5. Now this is probably a obvious thing but. WHAT EVER! It also allows you to set your aperture from 4.5 to the lower 2.8 setting giving you more control of the blurred background. I have another thread pertaining to this. Although this topic is very similar to, it the ending question is still different.

How much more blur control do you get over the background?

Is there really that big of a difference?

If I didnt need it for low light situations and only wanted it for more background control. SHOULD I STILL SPEND THE EXTRA MONEY AND BUY IT? Im trying to determine whether spending the money on newer 2.8 glass is worth it. Will I be 2.8 times as impressed with the background control?

 

[DerekSalem]

The difference definitely is huge. Going from 4.5 to 2.8 will allow a *lot* more light into the camera (meaning you can get a lot of pictures you couldn't get without it). It also gives you a *much* shallower depth of field. When you set it to f/2.8 it makes the aperture much *bigger* which means just about everything closer or further away than your target focus point will be out of focus. Pretty big difference unless you're far away.

Keep in mind, that 4.5 is the maximum aperture on your other lens (most likely). When you're zoomed in as far as it goes it most likely maximizes at 6.3 or so (which is *VASTLY* different from 2.8). You have to factor in your zoom because while your lens is probably 4.5-6.3 the 2.8 is 2.8 at all zooms.

 

[mrpink]

Will I be 2.8 times as impressed with the background control?

nope.

Investing in better glass is more than just "background control". There are other variables to consider such as sharpness, auto focus IQ, build quality, etc. When you factor in those improvements, yes- the higher end lenses are worth it. Will you be, as you say it, 2.8 times happier? Only you and your budget can answer that one. Will you be 2.8 times better at photography? No.

If you are taking paying gigs, which from your recent posts I assume you are, I would suggest in investing in better glass.




p!nK

 

[white]

"Hey gice, how do I get teh beautiful bokeh?!!1!"

:er:

I think you should buy the 2.8. You'll probably also need the 1.8 and the 1.4. And you'll need a zoom, too, so buy three or four new zooms.

 

[reznap]

You're just jealous of my tamron 17-50

 

[KmH]

How much more blur control do you get over the background?

How much more depends on the focal length of the lens, the lens to subject distance, and the subject to background distance.

Is there really that big of a difference?

Yes! If you understand what you are doing.

 

[table1349]

Some good reading.
Online Depth of Field Calculator
Understanding Camera Lenses
Understanding Depth of Field in Photography

The whole series:
Digital Photography Tutorials

Outstanding Bokeh is not just a product of wide aperture, but also the number of aperture blades in the lens. The more aperture blades generally the more pleasing the Bokeh. Like fast glass, more aperture blades, etc also add to the costs.

 

[Derrel]

The ironic thing is that with many f/2.8 lenses, one of the absolute best-performing f/stops is going to be f/4.5 to f/4.8, and stopping down to f/4.5 or f/4.8 will give you the depth of field needed for a satisfying portrait with many of the focal lengths in say a 70-200 f/2.8 zoom lens, or an 85mm, 100mm, or 135mm prime lens. On high-density sensors, like 12 megapixels on 1.5x or denser, diffraction kicks in at f/5.6 or so, so the absolute best resolution is actually right around f/4.5 or thereabouts...

I seldom shoot wide-open at f/2.8 at close distances...the image quality of "most" lenses is better once the lens is stopped down into the f/4.5 range. With longer lenses, like in the 70-300mm range, the depth of field at f/4.5 at close shooting distances, or with long subject to background distances, or at long focal lengths, is pretty shallow at f/2.8 and still quite shallow at f/4.5.

"Some" lenses are extremely good at f/2.8, like 300/2.8 and 200/2, with extremely high IQ at those wide apertures, but most zooms are noticeably better at one stop down, f/4, than they are at f/2.8.

 

[Vautrin]

It's all about exposure. You need a certain amount of light to expose your film / sensor properly which you get by:

Increasing / Decreasing shutter speed (time film is exposed)
Increasing / Decreasing aperature (amount of light let in)
Increasing / Decreasing sensitivity of film (ISO)

Most cameras deal in terms of doubling or halfing. So f. 2.0 lets in twice as much light as f 2.8. And ISO 200 is twice as sensitive as ISO 100.

So in bright light you're basically unlimited -- you can choose a very fast shutter speed and small aperature, or a big aperature or small shutter speed.

Indoors or in low light it's a different game because each of the factors I list above have bad points. The longer your shutter speed the more blur you'll get from people moving (or camera shake). The bigger the aperature the more "bokeh" and the higher the ISO the more noise.

In a situation like a wedding you can't really shoot any slower shutter speed then 1/30 since you'll get too much blur. Higher isos will get you too much noise. Bokeh is considered nice so that's the field you want to push.

Make sense?

 

[indeedies]

The ironic thing is that with many f/2.8 lenses, one of the absolute best-performing f/stops is going to be f/4.5 to f/4.8, and stopping down to f/4.5 or f/4.8 will give you the depth of field needed for a satisfying portrait with many of the focal lengths in say a 70-200 f/2.8 zoom lens, or an 85mm, 100mm, or 135mm prime lens. On high-density sensors, like 12 megapixels on 1.5x or denser, diffraction kicks in at f/5.6 or so, so the absolute best resolution is actually right around f/4.5 or thereabouts...

I seldom shoot wide-open at f/2.8 at close distances...the image quality of "most" lenses is better once the lens is stopped down into the f/4.5 range. With longer lenses, like in the 70-300mm range, the depth of field at f/4.5 at close shooting distances, or with long subject to background distances, or at long focal lengths, is pretty shallow at f/2.8 and still quite shallow at f/4.5.

"Some" lenses are extremely good at f/2.8, like 300/2.8 and 200/2, with extremely high IQ at those wide apertures, but most zooms are noticeably better at one stop down, f/4, than they are at f/2.8.

I agree with Derrel on this. I rarely shoot wide open on my Sigma 70-200. I stop down like Derrel suggested to get (what appears to me) the sharpness and clarity I'm hoping to acheive. And I usually want that much DOF so as to capture my entire subject.

The sigma was one of the best investments I've made thus far in my photography! I have the opporuntity to shoot wide open if need be and shooting at F4.5 or 5.6 is just so much nicer looking on this lens compared to my kit lens.

 

[flea77]

Derrel is correct in that most lenses are better stopped down at least one stop, but what he fails to mention is that this applies to ALL lenses. So if you have a lens where the maximum aperture is f2.8, then it will probably be sharpest around f4, but if you have a lens with a max of f4, then f5.6 would be the sharpest. So regardless of the lens, you lose a stop trying to sharpen it up.

Now that being said, I find my 2.8 lenses are acceptably sharp even at 2.8 for most uses and use them there quite frequently. That is one of the other advantages of pro glass, the actual glass is better.

Allan

 

[Village Idiot]

What he also fails to mention is many lenses with a wider maximum apeture, especially those that don't have a variable apeture through the zoom range are usually made with better components which will give you a sharper image wide open compared to a f/3.5-5.6 wide open or maybe even stopped down.

You do get what you pay for, although you're the one that has to decide if it's worth it.