lens recommendations

Hi I hava ki00d and am looking for a new zoom lens that will give me really good depth of field I only have the standard lens that came with the camera and find that the DoP isn't really upto much. DOes anyone have any recommendations, or point me in the right direction as to what to look for?

thanks

Depth of field has a specific meaning that refers to the range of camera-to-subject distances over which the picture appears sharp.

I suspect you don't mean this, and mean zoom range instead. Certainly the 18-55 mm zoom range of the kit lens isn't huge.

If I've read you right, I suspect you might get on very well with the Pentax 18-250 superzoom, which is an excellent lens considering its enormous zoom range.

Many here rate SRS Microsystems very highly, so assuming you're in the UK, this would be an ideal place to buy it.

Welcome to the forum...

What exactly do you mean by good Depth of field. Could you explain a bit more please or show us some pictures that shows what you are trying to say.

Also - what kind of stlye are you looking for. More wide angle og more zoom??

You need to learn a bit about the principles of photography.

Depth of field is a function of aperture. The smaller the aperture (say, f16 or f22), the larger the DOF will be.

Any lens of a particular focal length (or any zoom lens at a particular focal length) will have exactly the same DOF as another lens of similar focal length at the same aperture.

So take a few pictures at f22 (or f16 if it doesn't go to f22), and see how much DOF you get from your kit lens.

G

Yeah I know - got to start somewhere though, and I am going to go on a course. What I want is to manipulate the focus more than the current lens does blurry at the front, sharp in the middle blurry background that kind of thing.

Does the zoom range detract from the performance then - or is this simply a case of one lens trying to do everything?

Any other lens at the same settings would give identical DOF. Go into Manual or Av mode, and set the aperture to f16.

All zooms have to make compromises, and wide-range zooms have to make the biggest compromises.

G

Thanks, I'll try that. I still want to expand on my kit so you reckon the 18-250 superzoom would be a good addition then?

Superzooms are "slow" at the far end with a larger maximum aperture than you would get from a more ordinary zoom. Prime (non zoom) lenses tend to be faster still.

The "faster" (and longer) the lens, the narrower the depth-of-field can be, helping you to minimise the amount of the scene that is in focus. The lower the "F" number, the larger the aperture.

Lenses that I guess you would enjoy include:

Pentax FA 50mm F1.4 (new)
Pentax A 50mm F1.7 (second-hand)
Pentax A 28mm F2.8 (second-hand)
Tamron 70-300mm F3.5-5.6 (new)
Pentax 55-300mm (new)
Pentax M 100mm F2.8 (second-hand) (if you could cope with manual exposure)
Tamron 17-50mm F2.8 (new)
Sigma 18-50mm F2.8 (new)

Excellent thatnkyou very much

You're welcome.

I think that was only being suggested because people were assuming you meant a wide range instead of "really good depth of field". I think you mean the possibility of a small or narrow depth of field.

Yes I think you are correct it's all semantics, and it's easy to construe things wrongly on written forums rather than in person.

My apologies for misunderstanding you - it was I that started the confusion by guessing wrongly what you meant.

If you don't like the depth of field from the 18-55, I'm now guessing that what you're really looking for is a shallow depth of field.

This may be 'good' if your objective is to emphasise the point of focus by having everything at a different distance blurred. But it's 'bad' if you're trying to get the whole of something in focus, a face for instance. So perhaps you'll agree that it's just as easy to not say what you mean, as it is for someone to misconstrue what you say.

Anyway, if that is your intention, then Iceblinker's probably right with his list, with the possible exception of the 28mm, with which you'll have to be very close to get this effect to any great extent.

Out of them all, the FA 50mm F1.4 is probably the best for achieving a very shallow DoF: it's long enough not to have to get up too close, and it's fast enough to have an extremely shallow depth of field at F1.4 or F1.7.

However, you did also say that you wanted a zoom lens. Unless you pay an enormous amount of money, they do tend to be slower (that is, a smaller maximum aperture, or higher F-number wide open). Which means that you'll need longer focal lengths to get the shallow DoF effects.

Maybe you could be a bit more specific about exactly what you want to achieve, what sort of pictures you're thinking of taking, and how much you were thinking of spending.

You won't go wrong with the FA 50 1.4, though, it has a fantastic reputation for quality, and for around £150, it's very reasonably priced.

I don't think we can be sure what the OP means at the moment.

Could you please explain the problem, and we'll then know what you mean and be able to provide answers.

Wide-range zooms are for people who value convenience over quality. If that's you, it's not a bad buy.

G

this is called "shallow depth of field" since the distance over which focus appears sharp is quite short. This is achieved by using a wider aperture (say F4 instead of F8, or wider still if your lens allows). Depth of Field is also influenced by the focal length. Longer focal lengths have shallower depth of field at the same aperture.

Your kit lens has a fairly short focal length (18-55mm) and slow maximum aperture (F3.5-5.6). By contrast the 50mm FA F1.4 has a much faster maximum aperture, 4 full stops faster in fact, at close to the longest focal length the kit zoom offers. The 50mm F1.4 often has the opposite problem in fact, used wide open it is entirely possible that the persons eyes may be in focus and their nose is blurry!!