PentaxForums.com - View Single Post - Bokeh, Specular Highlights, Guess The Lens

carpents · 01-18-2008, 09:48 AM

Originally Posted by Jonas B

What are the designers thinking of?

You answered yourself (as did blende8) - sharpness.

Originally Posted by Jonas B

I enjoyed. Thank you for the links! The flower shot is pretty promising. Now we have the question: Why don't Pentax or Sony or anyone more STF lenses, and in shorter focal lengths?

Damian, I did get the link to load. (Must have been weighed down by all the PentaxForums traffic to it, ha ha.) I agree with you Jonas - that flower picture shows incredible promise given how that 50/1.7 renders naturally. (Which is to mean, quite poorly.)

Originally Posted by blende8

Perhaps we should push BOKEH more in the online fora, so that it becomes the single most important lens property, leaving behind sharpness and CA.

Indeed. My 'Normal Lens Shootout' was likewise criticized for undervaluing sharpness and overvaluing bokeh. For most, I think that sharpness is more important - and that is even among the small minority who care enough about photography to participate in on-line forums!!

If Pentax made a lens undercorrected for spherical aberrations just so it would render backgrounds nicely, I'm afraid it wouldn't really sell well. It would be relegated to the smallest of niche consumers.

Originally Posted by Jonas B

Now the tricky part. The STF set of aperture blades makes two things: it darkens the picture, just as the ordinary aperture, and it has an pleasing effect on the OOF parts of the picture by smoothening them. My guess is that the STF aperture blades are placed pretty close to the standard ones but still at a "plane" where we have a little more focus, sort of speaking. I think you can understand how I am thinking, but I have of course no grip of this.

Yes, yes, this makes perfect sense. What we are really trying to do is 'soften' the light around those sharp-edged aperture blades. But I wonder if the front-mounted filter would have an effect on some of the CA effects we see even if it doesn't help with the shape or distribution of the highlights.

I suspect you are correct about needing the room in a telephoto design to fit the STF portion. I guess this means your wide-angle dreams are not realistic. Maybe if they made a bigger-than-FF camera??? (Just kidding, even I don't think this will ever happen.)

01-18-2008, 09:48 AM	#103
carpents Pentaxian Location: West Chester, PA Gallery Photos: 0 Posts: 1,225	Originally Posted by Jonas B What are the designers thinking of? You answered yourself (as did blende8) - sharpness. Originally Posted by Jonas B I enjoyed. Thank you for the links! The flower shot is pretty promising. Now we have the question: Why don't Pentax or Sony or anyone more STF lenses, and in shorter focal lengths? Damian, I did get the link to load. (Must have been weighed down by all the PentaxForums traffic to it, ha ha.) I agree with you Jonas - that flower picture shows incredible promise given how that 50/1.7 renders naturally. (Which is to mean, quite poorly.) Originally Posted by blende8 Perhaps we should push BOKEH more in the online fora, so that it becomes the single most important lens property, leaving behind sharpness and CA. Indeed. My 'Normal Lens Shootout' was likewise criticized for undervaluing sharpness and overvaluing bokeh. For most, I think that sharpness is more important - and that is even among the small minority who care enough about photography to participate in on-line forums!! If Pentax made a lens undercorrected for spherical aberrations just so it would render backgrounds nicely, I'm afraid it wouldn't really sell well. It would be relegated to the smallest of niche consumers. Originally Posted by Jonas B Now the tricky part. The STF set of aperture blades makes two things: it darkens the picture, just as the ordinary aperture, and it has an pleasing effect on the OOF parts of the picture by smoothening them. My guess is that the STF aperture blades are placed pretty close to the standard ones but still at a "plane" where we have a little more focus, sort of speaking. I think you can understand how I am thinking, but I have of course no grip of this. Yes, yes, this makes perfect sense. What we are really trying to do is 'soften' the light around those sharp-edged aperture blades. But I wonder if the front-mounted filter would have an effect on some of the CA effects we see even if it doesn't help with the shape or distribution of the highlights. I suspect you are correct about needing the room in a telephoto design to fit the STF portion. I guess this means your wide-angle dreams are not realistic. Maybe if they made a bigger-than-FF camera??? (Just kidding, even I don't think this will ever happen.)