Hi,
I am considering one of these on D5100.
The usage will be mostly portraiture and candid street and occasional macro.
Was wondering which of these two lenses will blur the background more, when used wide open?
One is a stop faster, but shorter...and the other is slower but longer....
Lets say for a head and shoulder portrait....
regards,
nandadevieast
[quote name='nandadevieast' timestamp='1326645664' post='14883']
Hi,
I am considering one of these on D5100.
The usage will be mostly portraiture and candid street and occasional macro.
Was wondering which of these two lenses will blur the background more, when used wide open?
One is a stop faster, but shorter...and the other is slower but longer....
Lets say for a head and shoulder portrait....
regards,
nandadevieast
[/quote]
The blur should be roughly the same (just multiply the focal length by 1.4x per f-stop). However, the 60mm catches more background in terms of field of view. There has always been a debate about the "perfect" focal length for portraits - typically this is considered to be somewhere between 90mm and 135mm (full format) and both fall into this range. The choice is yours. ;-)
[quote name='nandadevieast' timestamp='1326645664' post='14883']
Hi,
I am considering one of these on D5100.
The usage will be mostly portraiture and candid street and occasional macro.
Was wondering which of these two lenses will blur the background more, when used wide open?
One is a stop faster, but shorter...and the other is slower but longer....
Lets say for a head and shoulder portrait....
regards,
nandadevieast
[/quote]
Considering we frame the subject similarly, the blur is mostly a function of the size of the aperture.
90mm / 2.8 = 32mm aperture
60mm / 2 = 30mm aperture.
As Klaus said, the blur will be about the same. It is more about field of view, which you prefer. I prefer the more narrow field of view myself, that then would be the Tamron 90mm. Which field of view you prefer is something you have to decide on yourself...
The 60mm f2 probably is a bit better wide open.
[quote name='nandadevieast' timestamp='1326645664' post='14883']
Hi,
I am considering one of these on D5100.
The usage will be mostly portraiture and candid street and occasional macro.
Was wondering which of these two lenses will blur the background more, when used wide open?
One is a stop faster, but shorter...and the other is slower but longer....
Lets say for a head and shoulder portrait....
regards,
nandadevieast
[/quote]
If you are in for a head and shoulder portrait, I would go for the 60mm lens. The 90mm (≈135 equiv) is just to long for that in my experience. Assuming a frame size of 75cm (30 inch) for the long side, you have the sitter 3m (about 10 feet) away from you. Most of the time I prefer to be closer to the subject. For the 60mm you would be 2m (about 7 feet) from the person.
I use 135mm equivalent already for pulling detail and compressed telephoto perspective.
Thanks.
Blur the background equally...For the same framing or the same distance?
Klaus: Can you elaborate, give me an example of 1.4x method you mentioned.
Brightcolours: What will be the DOF behind the subject wide open, if shot from the same distance from both the lenses? WHAT will be the DOF for the same framing? Which will blur the background more if the framing is same....
In terms of DOF/background blur, will these lenses behave like 60 and 90mm lenses or will they behave like 90 and 135mm lenses on a 1.5 crop camera?
In 35mm terms, the lenses are actually F4 and F2.8...so they will behave like this even on a crop camera, right?
Little complicated....but i will go by your general advice that both will blur the background equally.
Joachim: I like the 60 for its IF, i hate tubular lenses, visually.
[quote name='nandadevieast' timestamp='1326688922' post='14894']
Thanks.
Blur the background equally...For the same framing or the same distance?
Klaus: Can you elaborate, give me an example of 1.4x method you mentioned.
Brightcolours: What will be the DOF behind the subject wide open, if shot from the same distance from both the lenses? WHAT will be the DOF for the same framing? Which will blur the background more if the framing is same....
In terms of DOF/background blur, will these lenses behave like 60 and 90mm lenses or will they behave like 90 and 135mm lenses on a 1.5 crop camera?
[/quote]
My understanding is that the greater DOF on APS-C comes not from the lens somehow "losing" aperture (which it doesn't) but from the fact that the actual focal length (which is one of three primary factors for DOF) is not changing and therefore is shorter than what you would've been using on 24x36 format (unlike when you're using an extender that narrows the aperture and adds focal length by changing the optical construction of the lens system). Guess it could be verified by shooting same lens on different sensor sizes at identical apertures and distances, then cropping the larger format image to match the smaller one's framing - it's probably going to be identical WRT DOF and perspective. Why the heck should it not - it's the lens that builds the image, the camera only catches it, and how much of it actually makes it into the image is the only thing that differs with sensor sizes.
I guess Brightcolors is going to disagree, though. I wish I could do some testing to learn this for myself but I only have one camera, and the APS-C NEX-3 I have access to cannot mount Canon lenses. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='
' />
Quote:In 35mm terms, the lenses are actually F4 and F2.8...so they will behave like this even on a crop camera, right?
The 60 is better because it's F/2 for most purposes except maybe DOF calculation - most importantly for available light shooting. Depends on more than just that, the relative distances (camera-subject and subject-background) as well.
Quote:Joachim: I like the 60 for its IF, i hate tubular lenses, visually.
I have no experience with the 90 but loved the 60 when trying it out at the local photo fair. Nice portrait lens probably on every sensor size it's working with. Good coverage (about 80mm equivalent FOV - but since I'm not using FF cameras I'm not thinking in terms of equivalence) on my APS-H camera. Autofocus is not exactly top notch though, though I may be spoiled by Canon L and Sigma HSM lenses.
[quote name='Rover' timestamp='1326707581' post='14896']
My understanding is that the greater DOF on APS-C comes not from the lens somehow "losing" aperture (which it doesn't) but from the fact that the actual focal length (which is one of three primary factors for DOF) is not changing and therefore is shorter than what you would've been using on 24x36 format (unlike when you're using an extender that narrows the aperture and adds focal length by changing the optical construction of the lens system). Guess it could be verified by shooting same lens on different sensor sizes at identical apertures and distances, then cropping the larger format image to match the smaller one's framing - it's probably going to be identical WRT DOF and perspective. Why the heck should it not - it's the lens that builds the image, the camera only catches it, and how much of it actually makes it into the image is the only thing that differs with sensor sizes.
I guess Brightcolors is going to disagree, though. I wish I could do some testing to learn this for myself but I only have one camera, and the APS-C NEX-3 I have access to cannot mount Canon lenses. <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/sad.gif' class='bbc_emoticon' alt='
' />
[/quote]
What I wrote is correct, and you are missing something important. You are thinking of ONE lens on different formats.
We are talking about two different lenses on the same format.
Comparing one lens on different formats makes no sense. The field of view will be different, so there is nothing to compare expect that different field of view. APS-C will actually have a more shallow DOF impression in this scenario anyway, not more.
When we compare EQUIVALENT fields of view (so, different lenses) on different formats, what we should look for is equivalent apertures, not f-values. It is the size of the aperture which more or less determines the DOF. The f-value is just focal length divided by the aperture size. Anyway, I think I am confusing you more, here.
[quote name='Rover' timestamp='1326707581' post='14896']
The 60 is better because it's F/2 for most purposes except maybe DOF calculation - most importantly for available light shooting. Depends on more than just that, the relative distances (camera-subject and subject-background) as well.
[/quote]
One frames a subject (if one is a photographer), one is not nailed to the ground in one fixed position, so shooting with different focal lengths will still make the framing leading, not the distance from the photographer to the subject.
[quote name='nandadevieast' timestamp='1326688922' post='14894']
Thanks.
Blur the background equally...For the same framing or the same distance?
Klaus: Can you elaborate, give me an example of 1.4x method you mentioned.
Brightcolours: What will be the DOF behind the subject wide open, if shot from the same distance from both the lenses? WHAT will be the DOF for the same framing? Which will blur the background more if the framing is same....
In terms of DOF/background blur, will these lenses behave like 60 and 90mm lenses or will they behave like 90 and 135mm lenses on a 1.5 crop camera?
In 35mm terms, the lenses are actually F4 and F2.8...so they will behave like this even on a crop camera, right?
Little complicated....but i will go by your general advice that both will blur the background equally.
Joachim: I like the 60 for its IF, i hate tubular lenses, visually.
[/quote]
Blur the background equally for the same framing.
I prefer to talk about amount of blur, than depth of focus. To me it makes little to no sense in talking about same distance... one frames the subject, one does not make distance to subject leading.
The blur will be about the same with the subject same size in each photo. That is due to the same aperture size. The shorter lens will show more possible distracting background, though, giving a more busy impression.
In terms of how much they blur, they behave like lenses with a 30mm aperture. In terms of field of view, they behave like 90 and 135mm lenses on FF. And like 60 and 90mm lenses on APS-C.
Personal note:
I will prefer the 90mm for portraits for its narrower filed of view and tele compression of distances.
I will prefer the 60mm for macro for its wider field of view. Not a fan at all of the 90-105mm macro class on APS-C, prefer either shorter or longer.
Brightcolours:
I got what you are saying, thanks.
Field of view: They will behave like 90 and 135mm lenses on FF?
Should i put it this way? They will behave like 90 and 135mm lenses on APS-C, in 35mm terms. Right?
[quote name='nandadevieast' timestamp='1326727065' post='14906']
Brightcolours:
I got what you are saying, thanks.
Field of view: They will behave like 90 and 135mm lenses on FF?
Should i put it this way? They will behave like 90 and 135mm lenses on APS-C, in 35mm terms. Right?
[/quote]
Exactly.
Equivalent field of view of a 60 x 1.5 = 90mm lens on FF.
Equivalent DOF of an f2 x 1.5 = f3 lens of FF (close to f2.8)
Equivalent field of view of a 90 x 1.5 = 135mm lens on FF.
Equivalent DOF of an f2.8 x 1.5 = f4.,2 lens of FF (close to f4)