Canon 7D - General Purpose Zoom Lens

[here2rock]

Finally after some hard lessons I have purchased the Canon 7D.

Currently I have an old Canon 28-80mm, F3.5-5.6, Ultrasonic lens. This lens is fine and does the job.

I am thinking of upgrading the lens to a better quality general purpose/walk around lens. I have narrowed it down to these options:

1. Canon EF-S 17-55mm f/2.8 IS USM Lens

Pros:
Good quality finish
A constant f2.8 aperture throughout the range
Image Stabiliser
Shallow depths-of-fields and improved low-light performance

Cons:
It is very expensive, almost the same as L series lens
Not compatible with Full Frame bodies so no upgrade options

2. Canon EF 24-105mm f/4L IS USM Lens

Pros:
The equivalent of 168mm at the telephoto end much greater reach
It’s much better built, has weather sealing on the mounting and rings and Canon’s highest standards in optical design.
Silky smooth zoom and manual focus
It also comes with a lens hood
Image Stabilisation
It can be used on Full Frame bodies so no costs on lens in the future if I decide to purchase a FF
A constant f4.0 aperture throughout its zoom range

Cons:
Missing out on the true wide angle coverage of the general-purpose Canon 17-55mm f/2.8 IS USM Lens
Not as fast and bright as F2.8 lens in low light
It offers neither true wide angle capabilities, nor anything genuinely powerful at the long end on cropped bodies like Canon 7D

3. Canon EF 17-40mm f4.0L USM Lens
Pros:
Decent wide angle coverage
It’s much better built, has weather sealing on the mounting and rings and Canon’s highest standards in optical design.
Silky smooth zoom and manual focus
It also comes with a lens hood
It can be used on Full Frame bodies so no costs on lens in the future if I decide to purchase a FF
A constant f4.0 aperture throughout its zoom range
Much lighter build than the two lenses above

Cons:
Not as fast and bright as F2.8 lens in low light
It does not offer anything genuinely powerful at the long end on cropped bodies like Canon 7D
No Image Stabilisation

4. Canon EF 24-70mm f2.8L USM Lens f/2.8

Pros:
It’s much better built, has weather sealing on the mounting and rings and Canon’s highest standards in optical design.
Silky smooth zoom and manual focus
It can be used on Full Frame bodies so no costs on lens in the future if I decide to purchase a FF
A constant f2.8 aperture throughout its zoom range

Cons:
Not as fast and bright as F2.8 lens in low light
It does not offer anything genuinely powerful at the long end on cropped bodies like Canon 7D
No Image Stabilisation
Curvature at the wide end
It is probably due for an update
No Image Stabilisation

I am leaning more towards the option 2, Canon EF 24-105mm f/4L IS USM Lens. Only thing bothering me is the F4.0 V F2.8. I could probably live with not having a wide coverage. How important is F2.8 in general conditions? I can seem advantages in low light conditions but in normal light it should not have an advantage unless you want blurred backgrounds.

I will be getting prime lens in the future for low light and portrait shots, probable Canon 50mm F1.4. or 30mm with low F number.

[RichardTaylor]

I own a 24-105 and it is a good lens.

24mm would not be wide enough for me, especially in tight locations like street & waterfalls etc, on a crop camera (I use mine on a 5D)

If you have plenty of time F4 maximum aperture is fine for low light shooting, and with the IS makes for a very versatile walk around lens.
(if you don't have a lot of time then even F2.8 may be too slow for some shooting conditions)

Re DOF at f4

(1) Probably around minimum focussing distance. & 105mm



Camera Canon EOS 5D
Exposure 0.008 sec (1/125)
Aperture f/4.0
Focal Length 105 mm
ISO Speed 400
Exposure Bias 0 EV
Flash Off, Did not fire

(2) @f.4.5 & 105mm



Camera Canon EOS 5D
Exposure 0.005 sec (1/200)
Aperture f/4.5
Focal Length 105 mm
ISO Speed 100
Exposure Bias 0 EV
Flash Off, Did not fire

(3) @f4 & 24mm

Camera Canon EOS 5D
Exposure 0.025 sec (1/40)
Aperture f/4
Focal Length 24 mm
ISO Speed 1600
Exposure Bias -2/3 EV
Flash Flash did not fire

I do not own any other zooms in your list

[here2rock]

Some very nice photos of a lovely lady, I am guessing it is your wife.

I am really trying to understand the importance of F2.8 versus F4.0.

In good light conditions (we always don't have good light conditions), will a better quality F4 lens will give you a sharper quality pictures than a lower quality F2.8?

Richard you mentioned time "you have plenty of time F4 maximum aperture is fine for low light shooting, and with the IS makes for a very versatile walk around lens". What are you referrring to here? Are you referring to the movement of your subject?

What I have noticed so far with my very limited experience, The Sigma 50mm F1.4 lens (when the focus system worked on it) the pictures were sharper in low light. I did not need a lot of light indoors, I could work with a little light and the result will still be good. I am comparing this with a 15 years old 28-80mm 1:3.5-5.6 III lens. It is probably not a wrothwhile comparison as to the quality of pictures I am likely to get witht the Canon EF 24-105mm f/4L IS USM Lens.

[RichardTaylor]

Re time: It all depends on what you are shooting.

Plenty of time means you can do long exposures, either hand held or on a tripod, to meet your goals. With some subjects you do not have a lot of time if you want to "freeze" the subject.

Both theses examples are with the 24-105 on a 5D

(1) A border line case at a concert where 1/13 was not always enough to stop subject moving when shooting wide open and maximum ISO, even though my hand holding technique (with IS) was ok. (now days my preferred lenses for these events are F2 lenses)



Camera Canon EOS 5D
Exposure 0.077 sec (1/13)
Aperture f/4.0
Focal Length 45 mm
ISO Speed 3200
Exposure Bias 0 EV

(2) Relatively static subject where a slower shutter speed doesn't really matter.
Again hand held and illustrates the versatility of it as a travel lens. Taken whist on vacation.



Camera Canon EOS 5D
Exposure 0.067 sec (1/15)
Aperture f/4
Focal Length 40 mm
ISO Speed 1600
Exposure Bias 0 EV

--------------------------

I have a variety of lenses and one of the things you first notice with the better ones that it shooting at maximum (all else being equal) aperture is not a problem (they always appears sharp to me). With other lenses stopping down is very noticable IQ wise.

An example of mechanical problems; I have a Tamron 17-50 F2.8 (from about 4 years ago) and even though it is an F2.8 lens it has a lot of trouble focussing in low light which makes it virtually useless for the concert pics. In this case the 24-105 runs rings around it even though the f2.8 is an OK lens (not great) with more light.

In good light where you are shooting at F8-F11 (providing you have a lens that focusses ok for moving subjects (and some don't) it really doesn't make a lot of difference.

---------------------------

As far as F2.8 & F4 goes DOF wise it really doesn't make a huge difference if you are just chasing DOF (and can change focal lengths)
(From DOF Master)
On a 1.6 crop camera
50mm @ F2.8 & subject distance 5' = DOF ~ 4"
100 @ F4 & Subject distance 10' (so the subject is the same size) = DOF ~5"

However when shooting in tough (low light) conditions F2.8 may mean you may get a shot (due to subject motion or camera motion (no IS)) where at F4 you won't

[here2rock]

Can a prime lens be used as a general purpose lens? They are a lot cheaper with below 2.0 aperture number.

What is the most used focal length on a cropped body? I am kind of thinking 35mm could work really well for a cropped body.

[RichardTaylor]

We used to use prime lenses all the time a while back (zooms were not invented).

a 28-35/50/105-135) was in most shooters bags and the 50mm was the "standard lens" for a "full frame (35mm))" camera.

The equivalent on a crop camera would be a 35mm lens.

For me my most used prime lens is the Canon 135mm F2 L mainly because I like the reach and and the look of 135mm @ F2 and that lens can be a joy to use. It is my favourite lens but not my most used one.

"Quote"
What is the most used focal length on a cropped body? I am kind of thinking 35mm could work really well for a cropped body.
"End Quote"

It really depends on a persons style of shooting and what they are shooting - for me it would be a little tight and I would lean towards a 24mm for street/urban stuff.

Providing you have enough light, it may not really matter what lens you have on your camera, you just take a different style of photograph.

At the end of the day just keep in mind what do you want to use the lenses for.

For general purpose shooting a standard zoom is fine (and a good F2.8 can be may be ok in low light)
An ultrawide zoom will take care of the really tight shots and a long zoom will take care of those times when you want reach.
You may find times when you need (not want) something more (faster or macro etc) then make a choice for what you need.
Although I mostly use my 35mm f2 in concerts I sometimes just stick on if I want to take a walk and travel really light or it will be my back up lens whilst on vacations where I can't carry a lot of gear.

Some examples - all shot hand held in available light with a full frame camera.
(1)

Camera Canon EOS 5D
Exposure 0.025 sec (1/40)
Aperture f/5.6
Focal Length 35 mm
ISO Speed 1600

(2) Inside the State theatre.


Camera Canon EOS 5D
Exposure 0.025 sec (1/40)
Aperture f/2.0
Focal Length 35 mm
ISO Speed 1600

(3)

Camera Canon EOS 5D
Exposure 0.04 sec (1/25)
Aperture f/2.0
Focal Length 35 mm
ISO Speed 3200

(4)

Camera Canon EOS 5D
Exposure 0.04 sec (1/25)
Aperture f/2.0
Focal Length 35 mm
ISO Speed 3200

[here2rock]

Some very nice pics again Richard.

Choices, it is becoming very hard to make a decision, especially when you don't have a lot of lens in the kit already.

Richard, what would be your personal choice given my situation? Let's assume I may not even upgrade to a full frame body.

[RichardTaylor]

It's taken about 5 years (although I havn't purchased a new lens for the last 2 years) and I did make some mistakes.

On a crop camera for my style of shooting.

(1)
Canon EF-S 17-55mm f/2.8 IS USM - mainly because of its low light capabilities and focal length range


(2) I do a lot of shooting where I need reach.
Canon EF 100-400mm f/4.5-5.6 L IS USM Lens
(I own this lens)

An alternative is the Canon EF 70-300mm f/4-5.6 IS USM
A lot cheaper and lighter (I own this one as well and it is used when I have to travel a bit lighter.

If I want wider I would be looking at one of the ~10-24 zooms (I own a Tokina 12-24)

After that it tends to get a bit specific.
The less than 85mm fast (f2) primes may not be needed as you all ready have a good low light lens (#1)

If you want very fast & reach then a 135 F2 (I own one) may meet your needs or if you want just fast & IS I would be looking at a Canon EF 70-200mm f/2.8 L IS II USM (If I could justify it)

[here2rock]

If you are going to upgrade to a full frame then the choice between Canon EF-S 17-55mm f/2.8 IS USM and Canon EF 24-105mm f/4L IS USM Lens become a difficult one. It would not make an economic sense to spend $1200 on another zoom lens as 24-105mm will be good enough to do the job.

[RichardTaylor]

Quote
"Richard, what would be your personal choice given my situation? Let's assume I may not even upgrade to a full frame body. "
End quote


If you are going to get a full frame down the track (and keep in mind that doesn't necessarily mean replacing the 7D) then yes will change if you want "another walk" around lens.

Then you have a couple of choices in the Canon line up.

(1) 24-70 F2.8 L - this will help with low light stuff also and may mean you do not need to buy any fast primes.

or

(2) 24-105 F4 IS L (which is what I own) + at least two fast primes, if not 3, for the hand held low light shooting if need be.