Originally posted by dms As regards question 1, using a f/2.8 lens at f/8, and a f/4 lens at f/8--they should be similar as regards amount of light and depth of field (if same focus distance). If instead you started at about f/16 of f/22 and opened up the lens, as you get closer to the wide open setting you may expect better performance, and then within a stop or two from wide open increasing uncorrected aberations. But individual lens design will affect any comparison--it not being only about light transmission and depth of field.
More specifically about the two 100 mm Pentax lenses--I don't have/use either one--but there will be differences that you may or may not see yourself. But I think your own choices about distance and fstop will be the deciding parameters--and not the lens design.
Thanks. This is what I was looking for
Color rendering and final appearance of the shot will always be different with different lenses but I was definitely more into the technical aspect of the apperture thing...
There is one more thing (at least when the M and the D FA are in the game) but that is something I'll have to figure out on the way as I'm used to do all my macro shots with manual focus and manual settings. If I get a good connection with the model, I might use manual focusing as well... Then only the difference in color rendering will be the difference between the two lenses.
---------- Post added 12-25-16 at 07:41 ----------
Originally posted by clackers The Sigma could do just about everything from full body to head and shoulders for your shoot, Stein.
The wide open problems of all the lenses should disappear stopped down a couple of times.
As you say, you have to stop down anyway for DoF, you have good lights for f8 where the differences between lenses are minimal. Leave the ISO on 100, the shutter speed on 1/180s.
With the simple setup you're completely in command of, you can concentrate entirely on rapport with your model, getting the poses and expressions right.
Don't let an awkward silence happen, engage with her, not your camera, until the shots for each setup are finished.
The looks on her face will match her attitude towards you, so let optimism, warmth and creativity win over uncertainty and fiddling with camera gear. Ain't no one got time for that.
Good luck with it all!
Thanks
I have two Jinbei 300WS mono lights (adjustable in 60 steps independently) plus several other constant sources of light (for additional lightning if required), several backgrounds and all the its and bits I could need (soft boxes, reflectors, color gels, diffusers) and of course, sufficient amount of "juice" (D-BG5 with two sets of batteries) and two 32G SD cards in my K-3 II so I'm good with that. Making photos of people is much like driving a car - 80% psychology, 20% technical stuff. those 20% should not be the obstacle but should simply be something you simply do or don't for reasons you shouldn't think about while you do it. Those remaining 80% is the harder part if you have problems with your approach to people. I don't think I'm one of those. If I'd decide to approach someone and say "I'd like to make photos of you" I would most likely end up beaten up in a small and dark street. I never do that. I can't tell how I do that because it always depends on many things, but so far, I'm okay and all the woman I have ever asked for shooting decided to say yes, I'd like that... Guess there is something in the way I behave and the fact I never have the camera in my hand when I make an approach for the first time.
There is a set of rules I have and I clearly explain all of them when we get to the point that they ask me "how does it work?"... I'm pretty much serious and explicit about these things... No nudity or "adult content" is expected from the model. If they want to get their nude shot, they have to tell me that and ask for it - I will never suggest or ask for that. I'm married for like 30 years and have a wife and daughter so I'm not interested to get in any sort of relationship with the potential model except for being behind the camera. No touching. If I ever need to get close and say, move/straighten the hair, I do that with my left hand in a white cotton glove. I always suggest that the model comes with a friend or someone who will give additional feeling of being safe but that person should not interact by any means except with being there in the "background". I always explain what I want to get, and ask the model is there anything she wants to get in terms of final results (some woman do have really clear ideas about that, some have absolutely no preference) and then we agree on my sign language and what does mean when I ask her to turn her head to one or the other side or something like that. I use a whole set of movements and gestures to do that as they usually have absolutely no clue which side is "left" when I just say "left", so I move my head and my hand in front of my face in the direction I want them to move their head. Of course, I never forget to show them some of my printed/framed work and show them visually what I'm looking for so they can understand as clearly as possible what do I mean when I say "like it was shot in the 20's or 30's years of 20th century" And there are other things we discuss in order to get no mess anytime later...
For example, this is one of requests I had and the model was absolutely amazed and really happy about it...
Passion 2 | Robert Stein | Flickr