Overwhelmed with portrait lens choices...

[pjp]

Hiya folks!

 

I am transitioning from a point and shoot to a DSLR and just purchased a Sony A300. I'm going to take time to get

comfortable with the camera and accompanying kit lens but ultimately have the goal of shooting candid / portrait

shots of my 7 month old daughter.

 

I know I want a drastically out of focus background and have to have a low numbered f-stop (?) to acheive this. I run

into problems though when I shop for lenses. I can't figure out exactly HOW low of an f/ number I need (1.7 or 2.8

or...) and, for the life of me, how I can see one Minolta 50 mm 1.7 lens for $31 and right below it see another for $239

on E-Bay!

 

Any help you can lend is greatly appreciated. Don't be afraid to "dumb it down" for me... as I'm sure you can tell, I'm

a novice :)

[dlakelan]

Not that familiar with the Alpha lens line, but for a 1.5x crop body, the standard prime lenses for portraits are 50 and 85 mm.

 

For a given framing, the out of focus background is a function of the absolute focal length (not the crop factor equivalent). So you can really blow the background out of focus with long lenses like 100mm or more, but you have to be very far away from the subject...

 

f/2.0 or better is best for low light performance and out of focus backgrounds. f/2.8 is acceptable as well, especially on longer end. Anything with a smaller aperture (larger f/number) will not give you a good out of focus background.

 

if you can get a minolta 50mm f/1.7 in good condition, for $130 +- or so that would be the way to start IMHO.

 

One place to look for used stuff is http://www.keh.com

 

I have the tamron 17-50 mm f/2.8 and I think it's a good general purpose lens that includes portraiture at the long end. very sharp, not as good low light performance or extreme out of focus backgrounds as 50 f/1.8 on my canon but decent.

 

It looks like you might want to consider the Tamron 28-75 mm f/2.8 as well, relatively inexpensive, and covers the portrait and normal range. Bob Atkins has a favorable review on his site:

 

http://bobatkins.com/photography/reviews/tamron_28_75.html

[pjp]

Excellent answer Daniel, just direction I was looking for!!

 

If I may ask another question though: Say I was to go with the minolta 50mm f/17. I'm concerned about what others refer to as a "whisper-thin DOF." Is this going to be a problem for me if I am taking pictures of my daughter at close to conversational distances?

[matthew_newton]

Yes and no. It'll take some practice, but with autofocus there to help out things shouldn't be to bad. Just remember to keep the shutter speed up a little bit if you can.

 

I use a manual film camera with a 50mm f/1.4 lens for most of my portriture work of my 8 month old son. Wide open it takes a little patients and sometimes it takes 3-4 minutes just to snap a shot because he loves moving around so much these days.

 

Take a peak at my portfolio (or my website, link through my portfolio). Almost all of my pictures have the lens used for the picture. In most cases I use either a zuiko 50mm f/1.4 or a tamron 28mm f/2.5 or sigma 28mm f/1.8 lens for my baby pictures and most is done pretty close up (even a 28mm f/2.5 lens has pretty shallow depth of field at 18 inches).

[matthew_newton]

To expand, the reason it takes so long to snap a picture sometimes is that with manual focus and slow shutter speeds indoors its hard to get an in focus no-blur picture. Auto focus, the ability to pump up the iso a bit for higher shutter speeds and not worrying about some throw away pictures with digital it would be significantly easier to snap pictures with a fast 50mm lens wide open.

 

I enjoy a challenge though.

[dlakelan]

Penny,

 

Whisper thin depth of field can be a good thing, giving a soft look to some portions of the face...

 

On the other hand, if you want more depth of field, it is easy to shoot at a smaller aperture (larger f/number) the one that is listed on the lens is just the largest aperture available (smallest number) most lenses will go to f/16 so anything between f/1.7 and f/16 is available to you, if you have enough light... and each stop will increase the depth of field.

[pjp]

Thank you all for your help! I believe I'm finally starting to understand depth of field and all (well at least SOME of what) it entails :)

 

Matthew your infant shots are beautiful, as is your subject!

 

Daniel I appreciate you clearing up my confusion about the lens aperture size being permanent! Why did I not even consider that I had the option of closing my aperture siize as needed?? Duh, Penny! :)

 

Again though, thank you guys!!!!

[gerund]

Penny,

 

You can also achieve background blur in PS. Simple select what you want to stay in focus and do a Gaussian blur on the background. Sometimes you can get better control in PS than you can utilizing a lens to do it.

This is also easier when you have to control lighting as in outside shots and cannot use the larger lens opening because of excess sunlight.

[wentbackward]

Penny,

Given you are relatively new to an SLR, I'd recommend finding yourself a good book and trying things out. Something like "The New Photography Manual" by Chronical Books is pretty straightforward, colourful and won't baffle you with science whilst you learn your tools.

[glenn_mabbutt]

Just a general tip - if shallow depth-of-field is your goal for portraits (a good idea), you should use the "aperture priority" function of your camera - eg, you select a wide aperture (as wide as you want/can handle based on how much light you've got, what ISO you using, and what the max shutter speed of your camera is), and the camera will select the appropriate shutter speed for how much light you've got.

 

On a 35mm film camera I'm quite fond of the (all-manual) 85mm Jupiter-9 lens in M42 mount (there are adapters for a variety of cameras, including yours, I believe) - they're generally inexpensive, take great pics at wide apertures, but admittedly the all-manual nature takes some getting used to.