24-70 Canon Lens VS. the 24-105

[avalaurellesmommy]

I am relitively new to photography, just getting involved in it really seriously when my daughter was a year old (20 months now) I have a great camera the Canon Mark 5D II and use the 24-105 mm lens that it came with. I did attend a part time college course in order to better understand and use my camera - and have set up a home studio and I do have studio flash (alien bees)

I have found that I often have to really really ZOOM in AND/OR stand close to my "subject" in order to throw the background out of focus at f 4.0. When I am standing quite far back, everything at f 4.0 seems quite in focus and I'm not getting the effect of a blurred background that I'd like. I WAS assuming this has alot to do with the fact that my lens has a long focal length which I was told in class has an affect on the depth of field. That a wide angle - medium telephoto lens like the 24-105 that you may have to get closer to the subject to throw things out of focus.

I have read recently that you get a shallower depth of field with a telephoto lens (which when i am zoomed in it DOES put the background out of focus more) so I'm having trouble understanding why my teacher would have told me the fact that my lens was 24 - 105 would make it difficult to put the background out of focus when longer focal lengths give shallower depth of field ?

Since I do find my lens to put things out of focus when I am zoomed more towards the short telephoto focal length I guess it is true that I get shallower depth of field with a long focal length - but what I am wondering is if maybe the length of my lens in general affects the depth of field, does the fact that it is so long affect the depth of field at 4.0 differently than it would if I was shooting with the 24-70 lens at 4.0 ??? Will the background be out of focus more easily with a shorter lens or do I just rely on the smaller apeture for that ?

Either way, since I am having issues getting the desired look that I want, and was considering the 24-70 lens as it would allow me to shoot at f 2.8. Is there going to be a considerable difference between me shooting at 4.0 on a lens that has a shoter focal length than with the 24-105 that I currently have, or will I not see a difference between that ? And will there be a considerable difference between 2.8 apeture and 4.0 - is it really going to make a big difference (As I've said, I've never used a lens other than the 25-105 so I'm clueless about lower apetures)


If I am taking a picture standing lets say, 8 feet away from someone to throw the background out of focus, more should I take a few steps back and really zoom in to the more "telephoto" part of my lens which seems to throw the background out of focus - or should I just move forwards and not zoom too much as being closer helps to throw the background out of focus more ?

Is it worth my time and money to rent the 24-70 lens or does anyone find that theres not that great of a difference between 2.8 and f4 ?

 

[rufus5150]

The pink font on default forum gray background is nigh impossible to read.

 

[gsgary]

The pink font on default forum gray background is nigh impossible to read.

I thought it was just me

 

[MohaimenK]

That's kindda what I been thinking too. Although I haven't done a test yet but yes longer telefoto zoom will give you a shallower DOF. But it also has to do with the subject to scene. If the subject is larger in your frame, vs a small part of the frame. I will have to try my 70-200 2.8 at 70 and then use my 24-105 in the 105 range at f/4 to see the difference. I could post some samples later once I get home.

As far as the light, I haven't had any issue at f4 with dimmed light as we both know the MK2 has a fabulous ISO capabilities.

 

[Derrel]

I am relitively new to photography, just getting involved in it really seriously when my daughter was a year old (20 months now) I have a great camera the Canon Mark 5D II and use the 24-105 mm lens that it came with. I did attend a part time college course in order to better understand and use my camera - and have set up a home studio and I do have studio flash (alien bees)

I have found that I often have to really really ZOOM in AND/OR stand close to my "subject" in order to throw the background out of focus at f 4.0. When I am standing quite far back, everything at f 4.0 seems quite in focus and I'm not getting the effect of a blurred background that I'd like. I WAS assuming this has alot to do with the fact that my lens has a long focal length which I was told in class has an affect on the depth of field. That a wide angle - medium telephoto lens like the 24-105 that you may have to get closer to the subject to throw things out of focus.

I have read recently that you get a shallower depth of field with a telephoto lens (which when i am zoomed in it DOES put the background out of focus more) so I'm having trouble understanding why my teacher would have told me the fact that my lens was 24 - 105 would make it difficult to put the background out of focus when longer focal lengths give shallower depth of field ?

Since I do find my lens to put things out of focus when I am zoomed more towards the short telephoto focal length I guess it is true that I get shallower depth of field with a long focal length - but what I am wondering is if maybe the length of my lens in general affects the depth of field, does the fact that it is so long affect the depth of field at 4.0 differently than it would if I was shooting with the 24-70 lens at 4.0 ??? Will the background be out of focus more easily with a shorter lens or do I just rely on the smaller apeture for that ?

Either way, since I am having issues getting the desired look that I want, and was considering the 24-70 lens as it would allow me to shoot at f 2.8. Is there going to be a considerable difference between me shooting at 4.0 on a lens that has a shoter focal length than with the 24-105 that I currently have, or will I not see a difference between that ? And will there be a considerable difference between 2.8 apeture and 4.0 - is it really going to make a big difference (As I've said, I've never used a lens other than the 25-105 so I'm clueless about lower apetures)


If I am taking a picture standing lets say, 8 feet away from someone to throw the background out of focus, more should I take a few steps back and really zoom in to the more "telephoto" part of my lens which seems to throw the background out of focus - or should I just move forwards and not zoom too much as being closer helps to throw the background out of focus more ?

Is it worth my time and money to rent the 24-70 lens or does anyone find that theres not that great of a difference between 2.8 and f4 ?

Rufus....that's not pink..it is "plum". Isn't it pretty!?!?!?!?!

I verified the color...

 

[Village Idiot]

The pink font on default forum gray background is nigh impossible to read.

The pink font on default forum gray background is nigh impossible to read.

I thought it was just me

I didn't even bother...

 

[Big Mike]

I just drag-selected all the text...turns into white on blue, nice and easy to read. But ya, for future reference, don't use pink. :er:

Welcome to the forum, by the way.

The 'main' factor in getting a shallow DOF, is probably the lens aperture...followed by the distance to the subject and the focal length. As you have seen, it gets shallower as you get closer, but the problem therein is that you have to zoom the lens out, negating some of that shallow DOF that you want.

Another option is to move the subject farther away from the background, allowing it to get blurrier (farther away from your DOF).

So yes, getting a lens with a wider maximum aperture will help you to achieve what you want. But the 24-70mm F2.8 may not be the ideal choice for you. Since it sounds like your main goal is a shallow DOF, why not go for a prime (non-zoom) lens that has a much larger aperture than F2.8. For example, you might look at a 50mm F1.8 (or F1.4 or F1.2 L) an 85mm F1.8 (or F1.2 L). There is also a really nice 35mm F1.4 L and a 24mm F1.4 L.

Not only with the 'L' primes give you a wider aperture, but the image quality from those lenses, can be outstanding.

 

[imstuner]

You might want to look into a Sigma if you don't want to spend too much. I just got the Sigma F1.4 EX DG HSM and love it so far.

 

[Infidel]

tp;dr

 

[gsgary]

24-70 will blur the background at f8 70mm

 

[rufus5150]

The 'blur' is really a combination of: aperture blades/shape, f-stop, distance to the subject and distance to the background. Increasingly longer focal lengths give a narrower field of view, thus making the background 'farther away' (in most cases).

Landscape photographers can shoot a 100mm lens at F16 and get their whole scene front-to-back in focus. A macro shooter shooting at 100mm can shoot at F32 and get 1mm that's in focus.

But for all intents and purposes (some variations exist between lenses), lenses at 70mm at F4 will all blur roughly the same, assuming same distance to subject and same distance to background. Quality of blur may be a different story.

 

[soylentgreen]

I dare say give the 70-200 f/2.8 a try. If you do not want to be on top of your subject and want to isolate them with good bokeh, that's the way to go. I liked the 24-70 for events, but have to get too close sometimes to get the desired effect. The 70-200mm f/2.8L IS offers a good working distance and superior IQ. If you prefer a faster prime, definitely the 50 f/1.4 or 85 f/1.8 will do.