Best portrait lens macro

I am looking for advice on a portrait lens. I am considering the Pentax 50 mm 2.8 macro . Apart from the focal lens , can the macro feature be used for portraits , full lenth or 3/4 lenthgh . The macro feature is a 1:1 .
I have not dismissed the Pentax 35mm limited macro.
Doe anyone have any experience of these lens.
I am also considering the Sigma 17-70mm 2.8-7 macro.
Regards

The 50mm lens could be used for portraits, but probably not at 1:1 unless the portraits are of ants and flies etc. as 1:1 macro happens to be a very close focussing facility. The 35mm Limited is also a 1:1 macro lens.
If you already have an 18-55mm zoom you can get some idea from that as to what the prime lenses will give you at their respective focal lengths. In fact an 18-55 might well suffice for your (people) portraits.
The 35 & 50mm macros allow focusing much closer than the standard zoom which is useful if your subjects are small insects and maybe stamps and coins where the standard zoom cannot focus close enough. They focus to infinity too!
Both the 35mm ltd & 50mm macro are very sharp lenses. The 50mm macro is full frame and APS-C compatible, The 35mm Ltd is just APS-C (it vignettes on full frame.)
I don't know what lenses you have but worth considering is the newish Pentax 16-85mm or 18-135mm if you are in the market for a new lens. The Sigma 17-70 isn't a true macro, it just focuses fairly close, but what you describe as a requirement for portraits it doesn't sound like you really need a macro lens at all. By the way, Pentax make a 17-70mm too.
Have a look a https://en.wikipedia.org/wiki/Macro_photography to find out what macro lenses are for and see if they are what you really would like.

A true macro / portrait lens would be something like a Tamron 90mm, Sigma 105mm or Pentax 100mm

The Sigma has a focus lock so the focus throw can be limited like a normal lens for general shooting but can be unlocked for when you need macro magnifications.

Sigma 70mm f/2.8 EX DG Macro
got one, .. pretty versatile, excellent lens
here is a review :
http://www.imaging-resource.com/lenses/sigma/70mm-f2.8-ex-dg-macro/review/

Yes, on full frame, those were the typical lenses in the film days which is when they date from. Pentax's dedicated portrait lens was the 85mm soft focus. Crop sensors need perhaps a little less, 50-70mm is fine for APS-C. At the end of the day it depends on how much room you have as in a small room you may not be able to get far enough away with the longer focal lengths.
As for macro work, around 100mm is fine as it allows keeping a reasonable distance from the miniature subject. 35mm is really too close for that, though OK for flowers which don't take fright easily!

The Da50 is a very good lens. Very sharp from f2.8, good colour, good contrast and as a true macro lens, it is sharp across the frame. It is also a full frame lens. Not all of these attributes are always wanted on a portrait lens.

It will work for portraits, on APS C it covers the same field of view as a 75mm on full frame, on full frame it is a little short. Works well as a general 50mm lens and is a really good macro lens, although the 100mm is probably better for insects size subjects as it allows for a greater working distance. The 50mm is really good for document copying and such like subjects but it would be less of a problem on full frame.

Does depend really on the look you after it your portraits.
The maximum aperture of 2.8 is not the best for getting out of focus backgrounds on a 50mm, a larger aperture and/or longer focal length would be more useful for portraiture. A less sharp across the frame lens might be good for portraits as well.

I have the DA 35/2.8 limited lens and it's the best portrait lens I've ever used. However, if you want something longer then the 50mm would be better. I have the A version of that lens and it's very good, though I haven't had it for long and haven't used it for portraits at all.

Shameless point to my lens for sale on the classifieds Sigma 2.8 manual focus, auto aperture macro lens sharp images and perfect for portraits a gift at £75

link

I have a Sigma f1.4 50mm, it is an incredible lens and handles portraits fine. I can highly recommend this lens.

Review here: link

Nice!

Cheers guys , plently to consider , the Sigma does get good reviews , but seems unavailable from SRS and Park Cameras at least.(so no price comparisom).
At that focal lentgh the Da 70 limited may be a contender, budget permitting.
There is a studio I have used. Where i managed to shoot at 100mm on a Ks 1 , the studio is so big and doese have natural light , a rarity here in Glasgow.

Regards

I don't think macro lenses are usually good choices for portraiture. Personally I like to isolate my subject and a lens with a large aperture is best for that. As budget portrait choice I would suggest a DA 50mm f/1.8 or an secondhand FA or F 50mm lens (either f/1.4 or f/1.7) though they are as expensive as a new DA 50.

I would also recommend a macro lens for well macro photos. Get a Tamron/Sigma/Pentax 90/100/105mm macro if you are interested in insects. Or the DA 35mm Ltd macro for flowers and product shots. My experience is that all macrolenses I've had have been very sharp and dependable. Look for a good looking secondhand copy.

35mm is not useful for portraits (in the traditional sense) as far as I'm concerned.

I posted this the other day, if they get them back in stock then this is the best price you'll get the DFA 50/2.8 macro for:

http://www.johnlewis.com/pentax-smc-50mm-f-2-8-d-fa-macro-lens/p1091407

If you want a lens which does double-duty as a macro and general portrait lens then the 35 or 50mm macros are the best bet. Anything longer will severely limit your portrait options. However, in a studio environment (as you mentioned that's where you'll be) you may find that something in between would be a better length, such as the DA 70mm (of course this has no macro capabilities). Sigma made (make??) a 70mm macro lens though I don't know much about it.

For portrait get the Pentax 50 or 70, or Sigma 50f1.4 and then a few cheap extension tubes to turn the lens into a macro. Best of both worlds. The macro lenses are a good alternative but you need larger aperture lenses for portraiture.

Perfectly said

Every now and then the ability to use a fast aperture to limit the depth of field is invaluable on a portrait - even f2.8 is not always wide enough. When shooting macro you'll be stopping down for most subjects, and when you use a set of extension tubes (or a helicoid tube) you have more flexibility over the magnification ratio over a fixed macro lens (although moving the camera back and forth is probably as good ) .