24-70 vs 24-105

Kryptix

Kryptix

Messages
1,730
Edit My Images
Yes
Ignoring the aperture and IS, which is sharper?

Is the 24-70 sharp at f/2.8?

Which would be sharper at f/4?
 
The 24-105 looks a LOT sharper...
 
Kryptix said:
The 24-105 looks a LOT sharper...
Click to expand...

You reckon?

I mustn't understand these test charts. The 105 looks a bit better on the top third of the chart. But on the bottom two-thirds the 105 looks pretty appalling. Looks like there's colour fringing everywhere and it's soft as hell.

Now I wasn't impressed when I used a 24-105, but it didn't look that bad. What's the deal there?
 
A guy wants to swap his 3-month-old 24-70 for my 3-month-old 24-105 but I really don't want to regret it as I've got a sharp, mint copy of a 24-105 which I'm really happy with but I want f/2.8.
 
Kryptix said:
A guy wants to swap his 3-month-old 24-70 for my 3-month-old 24-105 but I really don't want to regret it as I've got a sharp, mint copy of a 24-105 which I'm really happy with but I want f/2.8.
Click to expand...

I've used both, but I too, wanted f2.8. So oddly, I now own a 24-70 f2.8.

Never bothered with in-depth tests, but I'd expect the 24-70 to be a bit better at f4 than the 105, just because the 105 is wide-open at f4. It's a heck of a lot better at 2.8 though.
 
24-70 is sharper according to reviews.

24-70 IS is out soon so might be worth waiting anyway.
 
To be honest though the test is hardly surprising, seen as though one lens is stopped down a bit and the other is wide open, stop the 24-105 down a bit and they get pretty close. even before looking at the test it's exactly what I'd expect from such a comparison.
It’s one of those questions only you can answer, as how much you want a 2.8 lens. To be honest if it were me I’d swap anyway (assuming the lens is perfect) as the 2.8 is a lot more expensive lens than the 24-105 (and you've got the 70-200 so you havn't got a gap in focal range).
 
Hawker said:
To be honest though the test is hardly surprising, seen as though one lens is stopped down a bit and the other is wide open, stop the 24-105 down a bit and they get pretty close. even before looking at the test it's exactly what I'd expect from such a comparison.
It’s one of those questions only you can answer, as how much you want a 2.8 lens. To be honest if it were me I’d swap anyway (assuming the lens is perfect) as the 2.8 is a lot more expensive lens than the 24-105 (and you've got the 70-200 so you havn't got a gap in focal range).
Click to expand...

I disagree with you, seeing as even at F8/11, the 24-70 at f2.8 still looks as sharp/sharper than the 24-105.

EDIT: Just looked again and it looks like I overexaggerated, but its still not that much sharper (looking at the bottom 2/3rds)
 
When is the 24-70 IS being released then?
 
It's only a rumour as the 24-70L is in reasonably short supply at the moment.

May happen, may not!
 
STARRIDER said:
Ive had both these lenses..the 105 is a great lens but the 24-70 is by far the better performer.....
Click to expand...

The simple fact that it's an f/2.8 body will mean that it'll appear sharper (on average) as xxD and xD bodies will command the lens to focus more accurately when using the centre focus point.

Bob
 
Kryptix said:
When is the 24-70 IS being released then?
Click to expand...

rumours are later this year, no one knows though and its only rumours but it would make sense to release it.
 
24-70 job done, are you worried about the wide end on crop as my 17-50 is <I mean looks as I haven't don anything empirical> sharper than my 80-200L at f2.8 which says its fair sharp though almost certainly not as good as these two - but a good tide over if you're waiting for the f2.8IS
 
I've owned both and settled (unlike everyone else it seems!) on the 24-105. Depends what you want to use the lens for I guess. There's more to life that f/2.8!
 
grumpybadger said:
I've owned both and settled (unlike everyone else it seems!) on the 24-105. Depends what you want to use the lens for I guess. There's more to life that f/2.8!
Click to expand...
Why did you settle for the 105? What does it have over the 70 other than reach?
 
I've got the 105 as well, and I bought it for three reasons, i; the range, more suited to what I wanted, ii; the cost at the time I couldn't afford the 24-70 and iii; at the time I didn't think I needed 2.8.
Now I'm down the line a bit, I'm pining after the 24-70. I do love my 105, but really would like an f2.8 lens now. With hind sight I should have bought the 24-70, but that's a bit of a mute point as i couldn't have afforded the 24-70 at the time anyway.
 
If you are going to be that picky, then I would question the whole validity of the ISO 12233 test chart procedure.

Mainly because it is a relatively small, flat 2D chart, shot at close distance. Wide zooms usually have a lot of field curvature, especially at close distance! There are three sizes of chart available, and assuming the largest one is used for this particular test it is only 1.4m wide, which means at 24mm focal length on the 1Ds3 test camera the chart is only about 1m away, and about 0.2m further away at the edges. Depth of field at that distance with the 24-70 at f/2.8 is about 0.3m, so straight away you are pushing right to the edge of DoF tolerance, even assuming a perfectly flat field :eek:

At f/2.8 with wide zooms, field curvature is very common, ie the centre of the frame and the edges achieve sharp focus at different distances. In the test procedure, it says the target is focused by AF centre point and live view, but it doesn't say if the edges are refocused to optimum, which of course would then throw the centre out. This seems crazy to me, and I guess it is why the manufacturers use MTF tests with a target simulated at infinity (links below).

So when you look at those test charts, particularly the botton bit taken from the frame edge, as it improves with increasing f/number, is this the result of the lens getting sharper, or simply depth of field pulling it in? I suspect this may be behind the problems they had with the 17-55 2.8 which got beat by the 18-55 kit lens, plus the fact that most lenses are not designed to give their best at close distance.

Since this is the main point of differentiation between all quality lenses, the validity of the whole test is brought into question. I have the same reservation about the tests done by DPReview and they acknowldge this shortcoming, but they also look for field curvature and comment on it when necessary.

The Canon graphs are here and it is obvious that the 24-70 is better, even at f/2.8. And it has that cool zooming lens hood.

24-70
http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&fcategoryid=149&modelid=8503

24-105
http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&fcategoryid=149&modelid=11924

Edit: FWIIW, I would take the 24-105; it's plenty sharp enough where it matters, has more range, is smaller, lighter and cheaper, plus it has IS.
 
HoppyUK said:
If you are going to be that picky, then I would question the whole validity of the ISO 12233 test chart procedure.

Mainly because it is a relatively small, flat 2D chart, shot at close distance. Wide zooms usually have a lot of field curvature, especially at close distance! There are three sizes of chart available, and assuming the largest one is used for this particular test it is only 1.4m wide, which means at 24mm focal length on the 1Ds3 test camera the chart is only about 1m away, and about 0.2m further away at the edges. Depth of field at that distance with the 24-70 at f/2.8 is about 0.3m, so straight away you are pushing right to the edge of DoF tolerance, even assuming a perfectly flat field :eek:

At f/2.8 with wide zooms, field curvature is very common, ie the centre of the frame and the edges achieve sharp focus at different distances. In the test procedure, it says the target is focused by AF centre point and live view, but it doesn't say if the edges are refocused to optimum, which of course would then throw the centre out. This seems crazy to me, and I guess it is why the manufacturers use MTF tests with a target simulated at infinity (links below).

So when you look at those test charts, particularly the botton bit taken from the frame edge, as it improves with increasing f/number, is this the result of the lens getting sharper, or simply depth of field pulling it in? I suspect this may be behind the problems they had with the 17-55 2.8 which got beat by the 18-55 kit lens, plus the fact that most lenses are not designed to give their best at close distance.

Since this is the main point of differentiation between all quality lenses, the validity of the whole test is brought into question. I have the same reservation about the tests done by DPReview and they acknowldge this shortcoming, but they also look for field curvature and comment on it when necessary.
Click to expand...
I think there are some good points here, but some not-so-good ones.

Good: I used to use the ISO test chart to test the sharpness of our lenses, but one day it dawned on me that I was really just testing them at or close to minimum focussing distance, which might not be terribly meaningful in the real world. Now if I could get one the size of the wall that would be fine, though a little cumbersome perhaps.

Very good: Field curvature is a real issue in this testing regime. I hadn't appreciated it previously, but of course it makes the results of a minimum-focus-distance test even less meaningful in the corners of the frame.

Not so good: I think the comments about depth of field are misleading. The difference between the distance to the centre of the target and the distance to the edge of the target is irrelevant if the target is perpendicular to the axis of the camera, because cameras (should) focus on a plane rather than on a sphere.

HoppyUK said:
FWIIW, I would take the 24-105; it's plenty sharp enough where it matters, has more range, is smaller, lighter and cheaper, plus it has IS.
Click to expand...
Me too.
 
Kryptix said:
Why did you settle for the 105? What does it have over the 70 other than reach?
Click to expand...

It's lighter, smaller and has IS...

As I say, it depends what you use it for. My 1D series cameras AF with high accuracy from f/4 and I only really take pictures outside so tend to be shooting at around f/8-f/16 most of the time anyway to get the DoF I need.

IS lets me push the shutter slower at the aperture I want without needing a tripod (I know I should be using a tripod but I sometimes get lazy)

Reach means I have to change lenses less.

The main downside I've found is that it has worse barrel distortion at the wide end than the 24-70.
 
I bought the 24-105 over the 24-70 as my main walkabout lens (replacement for the kit 18-55) because:

1. Extra range, I found I was always swapping over to my 70-200 for just that little bit longer. I don't carry it very often now, just carry my 100-400.
2. Weight - the 24-70 was significantly heavier than the 24-105, 950g against 670.
3. f2.8 didn't bother me as I'm getting low light shots handheld using the IS.


Now I know people will say about the depth of field etc but at times you just don't notice.

Here's a shot from yesterday - 1/200s f/4.0 at 105.0mm iso100:
114369573.jpg
 
StewartR said:
I think there are some good points here, but some not-so-good ones.

Good: I used to use the ISO test chart to test the sharpness of our lenses, but one day it dawned on me that I was really just testing them at or close to minimum focussing distance, which might not be terribly meaningful in the real world. Now if I could get one the size of the wall that would be fine, though a little cumbersome perhaps.

Very good: Field curvature is a real issue in this testing regime. I hadn't appreciated it previously, but of course it makes the results of a minimum-focus-distance test even less meaningful in the corners of the frame.

Not so good: I think the comments about depth of field are misleading. The difference between the distance to the centre of the target and the distance to the edge of the target is irrelevant if the target is perpendicular to the axis of the camera, because cameras (should) focus on a plane rather than on a sphere.

Me too.
Click to expand...

Agreed Stewart :) I did't express that very well. But to give a lens a flat field requires quite a bit of optical adjustment, given that the lens' natural tendancy is to focus on a concave plane, not a flat one.

Unless a lens makes some internal adjustment when moving to close focus (and some do) the designer has to make a guess at where to pitch for maximum field flatness, and they don't bother that much about it because in the real world we don't shoot flat 2D targets and a bit of field curvature doesn't matter a jot. At all other distances, they rely on depth of field to pull in the variance, which in practise is just fine.

Basically, testing a wide angle on a flat chart at close distance is a badly flawed business. Frankly, to the point of irrelevance, for a number of good and obvious reasons. No manufacturer or designer takes them seriously.

Case in point: on that site, pull up results for the 17-55 2.8 and 18-55 IS. We all know that the 17-55 2.8 lens is better, and the review goes to some lengths to say how good it is, but on the basis of the test results presented, the far cheaper kit lens blows it clean away :shake:

That review site is wonderful for pixel peeping, but when it comes to showing how good a wide angle lens really is, useless. Sorry, but there it is. Useless and meaningless.

Which is a shame, considering the amount of trouble they appear to go to setting the whole thing up. It woudn't be hard to produce a bigger target with a 3D element around the edges.
 
You must log in or register to reply here.
Back
Top