[twitch]

Thanks for the input. I guess it might laso be worth considering a prime. FA 77 springs to mind for only a little more than the Sigma 17-50. Or even the Sigma 85 (when it comes out in Pentax mount), although a lot more $ than the others. What about the Sigma 24-70, any good?

Not as good as the Tam 28-75, which I think would be an ideal 1 lens solution.

The FA77 is awesome, but should be added later, it's not exactly flexible.

[Pentaxor]

Thanks for the input. I guess it might laso be worth considering a prime. FA 77 springs to mind for only a little more than the Sigma 17-50. Or even the Sigma 85 (when it comes out in Pentax mount), although a lot more $ than the others. What about the Sigma 24-70, any good?

the Sigma 85 is already available in Pentax mount.

[Frogfish]

Wow ! A DA*15 - 60 ? Sounds like a great range

Agree with what has been said - you will get the best results from primes - some gorgeous MF lenses out there if you have the patience. However those aside then the Tamron 28-75/2.8 seems to be the best option for you (better than the 24-70), the 17-50 is definitely too wide no matter which version you buy.

Are the children to be posed in a controlled environment ?

If so other lenses to consider would be primes or zooms in the 50 - 100mm range, just throwing a few out there :
Sigma 50-150/2.8
Pentax *50-135/2.8
DA*70/2.4 Ltd.
FA 77/1.8 Ltd.
Sigma 70/2.8
Any fast, sharp 50/55

MF Lenses - lot of Pentaxes or maybe consider the fantastic Voigtlander range; 50/1.8, 58/1.4 or 90/3.5. Also the new Samyang 85. Huge range of used MF lenses to choose from though TBH.

[excanonfd]

I had one for about a year and never had any problems with the sdm but admit that I was concerned. I currently have 1 SDM lens and that is the DA* 300mm. I am reluctant to through out that kind of money the DA* lenses demand with a 1 year warranty and problems they have.

May you never have any problems with your DA* 300 - I might buy a DA 15 or 70mm primes if and when I could afford to but never another SDM lens. I bought one here in the forums that had already been serviced (SDM motor replaced). I thought it would be safe to buy, but who would have thought that the replacement motor would go on to fail as well. It's like having car that's been recalled and serviced, only to have the recalled problem flaring up again, or so it feels like to me. I have lost all confidence in Pentax SDM lenses, and I won't go near one, new or used.

Thanks,

[pop4]

DA 16-50* or Sigma 17-50?

I had to make that choice once, and for me, it was a no-brainer: the Sigma 17-50. There were too many stories of SDM failure (and also repeated failure) for my liking, and I didn't want to be yet another statistic. And I've been happy with my Sigma 17-50/28 thus far.
And as mentioned above, the Sigma 85/1.4 is already available in Pentax mount; I've got one.

[ozlizard]

Wow ! A DA*15 - 60 ? Sounds like a great range

Sorry about my dyslexia, I also suffer from insomnia, so I lay awake all night wondering if there is a dog

On a more serious note...I used a M50mm mf lens on my first photo shoot (borrowed). I found it difficult to use the mf with children. When I got the focus right the results were fantastic, sharp as a tack, but I also missed a lot. I might post a sample later. This is what got me thinking about a prime. If you use your feet you can do without a zoom. The question is, what is the best "bang for buck"?

[ozlizard]

A sample pic. Viewed at 100% in photoshop you can see the fine hairs on her lip.

\

[Frogfish]

Sorry about my dyslexia, I also suffer from insomnia, so I lay awake all night wondering if there is a dog

On a more serious note...I used a M50mm mf lens on my first photo shoot (borrowed). I found it difficult to use the mf with children. When I got the focus right the results were fantastic, sharp as a tack, but I also missed a lot. I might post a sample later. This is what got me thinking about a prime. If you use your feet you can do without a zoom. The question is, what is the best "bang for buck"?

Actually that's not quite true as by using your feet you are changing the perspective - however I doubt that is a major issue in studio portraiture.

[jstevewhite]

Actually that's not quite true as by using your feet you are changing the perspective - however I doubt that is a major issue in studio portraiture.

Zooming changes the perspective and FOV; moving the camera changes the framing of the subject, but not the perspective.

[Frogfish]

Zooming changes the perspective and FOV; moving the camera changes the framing of the subject, but not the perspective.

Sorry Steve - not right. Check out this link, it's got the best examples and explanation I've seen.

Perspective Control in Images - Focal Length or Distance? (a tutorial) - Canon Digital Photography Forums

[jstevewhite]

Sorry Steve - not right. Check out this link, it's got the best examples and explanation I've seen.

Perspective Control in Images - Focal Length or Distance? (a tutorial) - Canon Digital Photography Forums

Yeah, you're right, my bad; That's what I get for not paying attention. *sigh*. Sorry.

I know that stuff, too; thinking about the situation in a studio setting had me thinking about the wrong problems. Like maintaining the proper FOV to get a full length model shot in the studio while still cropping in the edges of the 9' paper sweep! - which can be a challenge. That is, the perspective changes as you zoom *while maintaining a constant subject size*; whereas when using primes, you back up till you get the perspective you want and then pick the lens. Of course, that's not really "zooming with your feet" in this context.

Good catch, too.

[Frogfish]

Yeah, you're right, my bad; That's what I get for not paying attention. *sigh*. Sorry.

I know that stuff, too; thinking about the situation in a studio setting had me thinking about the wrong problems. Like maintaining the proper FOV to get a full length model shot in the studio while still cropping in the edges of the 9' paper sweep! - which can be a challenge. That is, the perspective changes as you zoom *while maintaining a constant subject size*; whereas when using primes, you back up till you get the perspective you want and then pick the lens. Of course, that's not really "zooming with your feet" in this context.

Good catch, too.

Oh that's a problem I haven't come across yet. Guess you need a big studio !

I always keep that link because that is how someone corrected my misconception and it has come in handy many times. It can be very confusing at times .. even to those, like you, that know it anyway !

[mikeSF]

A sample pic. Viewed at 100% in photoshop you can see the fine hairs on her lip.

\

a gentleman never discusses the hairs on a woman's lip.

[jstevewhite]

Oh that's a problem I haven't come across yet. Guess you need a big studio !

I always keep that link because that is how someone corrected my misconception and it has come in handy many times. It can be very confusing at times .. even to those, like you, that know it anyway !

When you don't do it every day anymore *sigh*. I miss the studio, I miss the models, but I don't miss the art directors - nor the 'feast or famine' nature of the business

Terminology and context can become confusing, because it's reasonable to discuss it in both ways. It's like the FF/APS-c debate... do you compare based on the same FOV (subject framing), or the same focal length? Depending how you frame the question, the answers change. Do you talk about "zooming with your feet" vs "zooming with the lens" in terms of subject size and FOV, or distance to subject ( which give opposite answers ).

[MrPetkus]

FWIW, I use the Tamron 28-75 for almost all portrait work. I've done a lot of kids with it. It's so razor sharp that I frequently need to soften the images and pull back on clarity. But I'd much rather have a sharp lens that I may need to soften than vice versa. When I want thin DOF I use an old Pentax M50/1.4. For stage performance and the like I reach for the Tamron 70-200/2.8. And wide angle goes to the Pentax 15/4. I would like something between the 15 and 28 (21/3.2?) then I'd have the perfect kit. And the 31 - just because...