[VisualDarkness]

I would get the 50-135 before the Sigma any day due to the weather sealing and after the hack for disabling the SDM you can always revert to screw drive. Between the 70/2.4 and the 50-135/2.8 I'm torn. Both are simply wonderful and you can't really go wrong with either. Flexibility and weather sealing or slightly better sharpness in a very small package that you always can put in your pocket, both with superb optics. Sorry, I can't help you. :P

[Docrwm]

I'm mostly using either my F50 or my Sigma 17-70 for portraits, but when I'm in a studio location with enough space I use exclusively the 50. I have a 100 macro and find it too tight in all situations.

If I had a 40 and a 70, I might switch between those two and be a happy camper. Otherwise, I think the 50-135 covers a nice range for studio (I also own a 21 but would never use it for portraits, it's more of a landscape lens).

If you are doing studio portrait, then considering that you own a 40 I'd go for a 70. If you shoot candids or on-location portraits, I would certainly select the 50-135.

Interesting, if I have the space I find the 70 (or my 85/1.4 Samyang) produce photos that are so much more pleasing than my 40 Ltd. The 40 comes out when space is at a premium or I'm walking around but for portraits it just leaves me flat when I have used it, so I don't any more.

[Dice]

I have both the DA70 and 50-135. Aside from the obvious differences size, zoom vs. prime, I don't see much difference in sharpness. It took me a while until I got the DA70 properly dialed in but it is slightly sharper than the 50-135. I also have the sigma 70 macro and I like the rendering/color of portraits on the Pentax lens. But if sharpness is what you are after at 70 mm the sigma is hard to beat. another difference that I see with the DA70 and 50-135 is color. The DA* is slightly warmer overall. Where as the DA has the typical LTD colors which are lovely. Lastly the DA* does a better job with Chromatic aberrations. The Sigma is worse than the DA70 in this regard. All of my comments are just that....mainly observed from pixel peeping and none are from specific side by side testing. If you like 70 mm and want to use it for portraits and money is not a major consideration go with the Pentax DA70. If you want to save a few bucks go with the Sigma it does a great job and does fantastic macro. Having said that I would not sell my 50-135 to anybody. I've had it for about 4 years and it is a fantastic lens across the zoom. It is like having a handful of primes.

[Rondec]

I currently own the FA 77 and the DA *50-135 and used to own the DA 70. Between them, I would probably choose the DA *50-135, mainly due to flexibility. It is sharp at f2.8 throughout the range (a little soft corners at the long end). The DA 70 is only a half stop faster, is a little sharper, but not enough that I would see it as being a great difference.

The FA 77 would be a harder choice (I understand that it is out of your price range), because it is so much faster and is sharp from f1.8. Its biggest down sides are the slower auto focus and pretty bad purple fringing.

[Croneberg]

Good morning guys!

Well, those a quite a few answers! Thanks for your advice! I really thought about the pros and cons all of you mentioned and I just can't get the DA* out of my mind. The versatility of the zoom is a big plus at least in my book. I love the fact that I can shoot at 50mm, which is still a focal length which you can use for general-purpose shooting, all the way up to 135mm which I think is great for candid portraits as well as work which requires a short tele (like concerts and stuff). I really want to get more into portraiture at parties and events and I think the versatility would be a big plus when switching lenses is not an option.

I scheduled a meeting tomorrow to take a look at the used DA* and to get an impression of the size and weight this thing has. This is the only thing which sits in my mind and keeps bothering me. But I have to look for myself since the definitions of big and heavy certainly are very personal.

Regarding the SDM I read on the forums and on other sites, that if the motor didn't fail in the first three or so years it probably is going to be ok (forever?). If a lens has failed within that timeframe it was likely to fail again - there are a lot of postings and reviews on Amazon and the forums from people with multiple SDM-failures that confirm this statement. But even if it should fail the cost of repairing plus the price of the used lens would still be way under the price of a new one, which could have the problem just as the used one (599€ vs 950€)!

I'll just have to wait till tomorrow when I can get my hands on the thing. I will keep you posted!

[Rondec]

Good morning guys!

Well, those a quite a few answers! Thanks for your advice! I really thought about the pros and cons all of you mentioned and I just can't get the DA* out of my mind. The versatility of the zoom is a big plus at least in my book. I love the fact that I can shoot at 50mm, which is still a focal length which you can use for general-purpose shooting, all the way up to 135mm which I think is great for candid portraits as well as work which requires a short tele (like concerts and stuff). I really want to get more into portraiture at parties and events and I think the versatility would be a big plus when switching lenses is not an option.

I scheduled a meeting tomorrow to take a look at the used DA* and to get an impression of the size and weight this thing has. This is the only thing which sits in my mind and keeps bothering me. But I have to look for myself since the definitions of big and heavy certainly are very personal.

Regarding the SDM I read on the forums and on other sites, that if the motor didn't fail in the first three or so years it probably is going to be ok (forever?). If a lens has failed within that timeframe it was likely to fail again - there are a lot of postings and reviews on Amazon and the forums from people with multiple SDM-failures that confirm this statement. But even if it should fail the cost of repairing plus the price of the used lens would still be way under the price of a new one, which could have the problem just as the used one (599€ vs 950€)!

I'll just have to wait till tomorrow when I can get my hands on the thing. I will keep you posted!

My 50-135 is five years old and the motor seems to be fine, but nothing lasts forever. If you are OK with the noise of screw drive, there is the hack that someone posted earlier that allows you to change your lens into a screw drive only lens. It doesn't change the speed of the auto focus, just adds some noise to the focusing.

[Croneberg]

My 50-135 is five years old and the motor seems to be fine, but nothing lasts forever. If you are OK with the noise of screw drive, there is the hack that someone posted earlier that allows you to change your lens into a screw drive only lens. It doesn't change the speed of the auto focus, just adds some noise to the focusing.

In case of a SDM-failure, depending on how long I have had the lens, I'll probably just send it in for repair. I think I can beat down the price of the used copy to about 550€ (around 717$) which is a heck of a lot cheaper than a new one which costs about 950€ (~1.240$)!

Maybe I'm gonna try that hack but is it reversible? I don't want to hack the lens and then someday I convince myself to send it in for repair just to find out that Pentax denies repairing it due to the hack.

[Rondec]

In case of a SDM-failure, depending on how long I have had the lens, I'll probably just send it in for repair. I think I can beat down the price of the used copy to about 550€ (around 717$) which is a heck of a lot cheaper than a new one which costs about 950€ (~1.240$)!

Maybe I'm gonna try that hack but is it reversible? I don't want to hack the lens and then someday I convince myself to send it in for repair just to find out that Pentax denies repairing it due to the hack.

I believe it is reversable, as long as you have a camera where you can get into the debug mode. If you didn't own a kx or a K10, then you would probably be out of luck.

[Croneberg]

I believe it is reversable, as long as you have a camera where you can get into the debug mode. If you didn't own a kx or a K10, then you would probably be out of luck.

I have a k-5 here, but I think I read somewhere, that it's possible to access the debug mode with a software called "PK Tether"...

[Kerrowdown]

I'd go for a 70

+1 me too, but I just love primes, so I'm not really the one to ask.

[bdery]

Interesting, if I have the space I find the 70 (or my 85/1.4 Samyang) produce photos that are so much more pleasing than my 40 Ltd. The 40 comes out when space is at a premium or I'm walking around but for portraits it just leaves me flat when I have used it, so I don't any more.

Maybe the 40 and the F50 are different for portraits, I don't own the 40. I just assumed that given its stellar reputation and the fact that 40mm is somewhat near 50, it would behave similarly. Plus sometimes when space is tight the 50 is a bit narrow.

[Croneberg]

+1 me too, but I just love primes, so I'm not really the one to ask.

The thing is, me too! I love my 40mm Limited, K 55mm 1.8 and K 135mm 3.5 but besides portraiture I also want to get more into event photography in the near future, where changing your lenses may cost you that certain moment and switching lenses in the dark between a lot of people is a thing I am not too fond of as well! Tomorrow I'll know if the weight and size difference of the DA* in comparison to primes is worth the versatility of the zoom.

[Docrwm]

The thing is, me too! I love my 40mm Limited, K 55mm 1.8 and K 135mm 3.5 but besides portraiture I also want to get more into event photography in the near future, where changing your lenses may cost you that certain moment and switching lenses in the dark between a lot of people is a thing I am not too fond of as well! Tomorrow I'll know if the weight and size difference of the DA* in comparison to primes is worth the versatility of the zoom.

Those are the reasons Zooms exist - convenience and the instant ability to change perspective without changing lenses. Sounds like you've answered your own question

[Kerrowdown]

changing your lenses may cost you that certain moment and switching lenses in the dark

That's why I always run multiple bodies, also it gives me built in back up, as for me failure is not an option.

[Croneberg]

That's why I always run multiple bodies, also it gives me built in back up, as for me failure is not an option.

Yeah but neither do I have the money to buy another body just for those occasions nor do I really want to carry two bodies with me. It would be a complete overkill.