[Digitalis]

It's not just a matter of f/1.8 being thinner than f/2.4, there's something more to it that results in the DA lenses having a better hit rate with AF accuracy

It is because at the widest aperture the FA77 has an inherently lower contrast than the DA70 - and the AF in our cameras relies on detecting contrasts in the AF frame in order to bring subjects into focus, so with a contrasty lens the AF will lock on faster. There is also the fact that the focus travel on the FA77 is greater than the DA70 that slows AF down quite a bit too.

[Marc Sabatella]

Marc you make some fine points, and in the first post the OP did say if someone can prove him wrong they might reconsider the 28-75. My post wasn't just directed toward you though, but instead it was an effort to keep this on track. It's not a "comparison" thread, but a "suggestion" thread.

Exactly, and my suggestion based on everything else the OP said is, the Tamron 28-75 is the most obviously ideal choice. So I do think it important to ascertain just what led the OP to the conclusion that it would somehow not work out for him. Given that he has apparently never used it but is basing his opinion on shots posted by others - shot under who knows circumapstances, proessed in who knows what ways and with who knows what creative vision in mind, I would maintain it is absolutely in his best interest to not toss this lens out of consideration but to actually give it a fair chance.

[twitch]

It is because at the widest aperture the FA77 has an inherently lower contrast than the DA70 - and the AF in our cameras relies on detecting contrasts in the AF frame in order to bring subjects into focus, so with a contrasty lens the AF will lock on faster. There is also the fact that the focus travel on the FA77 is greater than the DA70 that slows AF down quite a bit too.

That makes a lot of sense to me, thanks Maybe that explains why Pentax didn't try and make a 50 f/1.2 AF lens? My K50 @ 1.2 photos have a fair bit less contrast than my FA@1.8 pics.

[Digitalis]

Maybe that explains why Pentax didn't try and make a 50 f/1.2 AF lens?

I would say it is one of the principal reasons why they haven't. Canon photographers have enough trouble with field curvature and inaccurate focusing with their f/1.2's as things are.

[danielchtong]

I am used to long lens even for portrait. But sure my F50mm F1.7 is cheap enough if somehow it is available in ebay







See the toper left. There actually was the socks of another photographer. It has been so blurred up that it does not matter at all.

I would say it is one of the principal reasons why they haven't. Canon photographers have enough trouble with field curvature and inaccurate focusing with their f/1.2's as things are.

F2 is the widest aperture I use.


Daniel

[Digitalis]

F2 is the widest aperture I use.

I have no issues with using my Pentax-K 50mm f/1.2 @ f/1.2 - however I agree with the Canon EF50mm f/1.2L f/2 is where the bokeh/contrast/sharpness trifecta lies, though the same could be said for the Pentax lens which i'm sure in a head-to-head test the Pentax 50mm f/1.2 would come out on top.

[danielchtong]

I just recently got a K-5, and it is amazing! I also ordered an m 50mm 1.7, so I am in need of another portrait lens! Many people reffered me to the Tamon 28-75, and I have looked through THOUSANDS of photos from that lens, but I still have not seen a photo with decent IQ. Any suggestions for another lens with a similar price range would be great! Or if you could try to convince me the Tamron is worthy, that would be helpful as well!

Another inexpensive solution is to get one of the M135mmF3.5 which is very good in isolating the subject and female close up (with very flattering effect)

Portraits 135mm - Steve's Digicams Forums


Daniel

[nick52]

For the sharpness agruement: Sharpness produced by a lens looks better than sharpness compensated for in photoshop. I would rather have an extremely sharp lens and soften the client's skin in photoshop. (easier, and better in my opinion)

For the Tamron: I guess the photos I went through were user errors from "Photographers" (using that term lightly). From the other photos I have seen, I will probably get it due to conveniece and IQ. I will still probably get the sigma 30mm beause it is great with infinity focus shots and the DOF is creamy and acute at the same time :-)

*my decision does not have to do with the nearly aggressive attacking on my first opinions of the Tamron. LOL

I may look into that M135, I have heard tales....

[RioRico]

For the sharpness agruement: Sharpness produced by a lens looks better than sharpness compensated for in photoshop. I would rather have an extremely sharp lens and soften the client's skin in photoshop. (easier, and better in my opinion)

For extreme sharpness, use a macro or enlarger lens. Nice as my Jupiter-9 and Nikkor 85/2s are, my Vivitar-LU 75/3.5 (enlarger) and Vivitar-Komine 90/2.8 (macro) are hard to beat. But these flatfield-sharp lenses lack the 'pop' of my Meyer Trioplan 100/2.8 and SuperTak 105/2.8. Some projector lenses (no iris; shoot wide-open) seem to be based on the ancient Petzval Portrait formula, with much 'pop'. It ain't easy to add pop in photoshop, eh?

I may look into that M135, I have heard tales....

A splendid lens, and so small!

[lytrytyr]

Another inexpensive solution is to get one of the M135mmF3.5 which is very good in isolating the subject and female close up (with very flattering effect)

Portraits 135mm - Steve's Digicams Forums

"Beauty is in the eye of the beholder,"
but I personally find the sharpness of the M135/3.5
less than flattering here,
for example the way it picks up
the veins on the model's hand and upper arm in No. 1.

The circumstances Daniel describes sound less than ideal,
but I've a feeling that something like my old M42 Soligor 135/2.8,
which would never be found guilty of sharpness wide open,
might have been gentler on the subject.

[danielchtong]

"Beauty is in the eye of the beholder,"
but I personally find the sharpness of the M135/3.5
less than flattering here,.

I brought up the M135mmF3.5 is because at F3.5 , it is not that sharp which is exactly what I like

I do not have that M135mm now.
But this was from FA135mm

.

The AF function sometimes is important in catching the right moment in a crowded setting

Any 135mm can throw a bokeh (subject to taste) easily at wider aperture.


Daniel

[Digitalis]

Personally I do not like using lenses that are much longer than 85mm for portraiture on APS-C cameras because the working distance is too long, I prefer to be closer to the model and be able to communicate with them*. For a majority of my portraiture work with Pentax cameras I use the SMCP-K 50mm f/1.2 which gives a decent working distance while providing shallow DOF at f/1.2 and biting sharpness across the frame at apertures f/2.8 and smaller. One of the reasons I am so fond of 50mm lenses is because they have split personalities. Though for product photography/still life work in the studio I often use the Pentax FA*200mm f/4 ED Macro mainly because it is apochromatic and extraordinarily sharp therefore it requires less time in PP to correct for optical deficiencies.


*This is largely a professional as well as a personal consideration as the average space in photography studios I have worked in is around 10mx5m.

[yusuf]

I just recently got a K-5, and it is amazing! I also ordered an m 50mm 1.7, so I am in need of another portrait lens! Many people reffered me to the Tamon 28-75, and I have looked through THOUSANDS of photos from that lens, but I still have not seen a photo with decent IQ.

Here are some shots from my 28-75mm, all at f2.8, hopefully you may find IQ good enough for your liking

[liukaitc]

u know what is the most widely used potrait lens for professional full-frame canon and nikon photographer?
that is 70-200 f2.8..they use it everywhere.
so to pentax that is 50-135 f2.8...though it is like 70-200 f4 for full frame

in my opinon..unless u want that f1.4 f1.8 dof and bokeh look..go with 50-135...can change perspective with one lens is really a plus for potrait

[Digitalis]

u know what is the most widely used potrait lens for professional full-frame canon and nikon photographer?

no, that is a more common practice amongst amateur~semi-professional wedding photographers that must have a lens that they can get away with using for everything, in the end this approach becomes painfully obvious because all the shots have the same look, the same perspective. Professionals use whatever they have to so they can get the job done, which means not getting sucked into using a particular type of lens just because a majority of people in the industry uses them.I like to be creative with my work and for me the Pentax 50mm f/1.2 is my lens of choice..but I have used plenty of lenses for portraiture over the years and I always kept coming back to 50mm. With my full frame DSLR cameras I use 75~80mm prime lenses for portraiture. On my Leica M9 the Leica 75mm f/1.4 Summilux-M is an excellent choice, on my Canon 1Ds MKIII I use a modified Leica 80mm f/1.4 Summilux-R - mainly because I cannot stand the focus by wire mechanism on the Canon EF 85mm f/1.2L*


* I cannot believe that the canon lens still has that "feature", I worked with an Olympus DSLR once - and that had the same focus by wire mechanism and I absolutely hated it.