Ultrawide on Alpha 900 / Sig 12-24 or Minnie 17-35/2.4-4

[David Kilpatrick]

I have cropped some examples, but remember this is stock photography. Generally, it's better not to crop even if composed with a deep foreground and better as a square. Such images often sell for magazine covers, full pages etc where the 'dead space' is valuable for layouts - a whole stack of text headlines, or even secondary pictures, can be dropped in over the steps and the sky is large enough to incorporate typical magazine logo space.

If you want to know about the radiating clouds, it is a function of ultra wide lenses. I explained it in my first ever article for MINOLTA MIRROR (1975 annual), with perspective diagrams, and I have never fully revisited the concept. It even works with dull days if there's a bit of cloud texture. I worked out how lenses like 20mm/17mm enabled a different relationship with the sky - in particular - right at the beginning of my photographic career and I've used it ever since. Another function of wide-angle lenses is to make round objects look more spherical. This was taught to me, I didn't work it out for myself but learned it from a top food photographer around 1981. By using a wide lens, I can make a skinny Christmas turkey (or Thanksgiving turkey) look twice its weight.

Try it yourself. Next time you have a roast chicken or anything similar, take a snap with a 100mm lens (nice comfortable distance etc) and then move in really close with a 24mm or 28mm. Compare the two results (be sure to keep the bird exactly the same overall size). You will realise how easy it is for a 'white background' product photographer to make many items look more substantial, without looking distorted.

David

[David Kilpatrick]

Thanks for your reply David. It is as I feared, probably my copy of the lens. While it is totally usable at 12mm (which is, after all, why I originally bought it!) I really don't think photos taken above 16mm would pass Alamy QC, so I haven't bothered submitting any. I'll do a few tests to see whether it might be BF or FF, but if it nails the focus at 12mm, I don't think it's likely to be a focusing issue. What do you think?

Philip

The focus may look worse at longer lengths - after all, it's really just enlarging a 12mm view optically to create its zoom range, and that would enlarge any softness. My shots did not look sharp on the camera screen even when they proved to be OK once processed. I may have used manual focusing needlessly, the early AF shots all actually seem OK. And so far, all the pix have passed Alamy QC at full 24 megapixel size.

David

[Greg Beetham]

Now that you mention it David, I do seem to recall seeing that cloud receding effect before with wide angle, it might even have been something I took at some point, but alas I can't remember where or when, my photographic memory is a bit wonky.
And yes I can imagine that the close wide angle product shot would perhaps be more dramatic but the depth of view would become fairly critical...I assume, I'm thinking probably f18-f22.
Greg

[David Kilpatrick]

Now that you mention it David, I do seem to recall seeing that cloud receding effect before with wide angle, it might even have been something I took at some point, but alas I can't remember where or when, my photographic memory is a bit wonky.
And yes I can imagine that the close wide angle product shot would perhaps be more dramatic but the depth of view would become fairly critical...I assume, I'm thinking probably f18-f22.
Greg

For the same subject scale, depth of field stays constant with changes of focal length. If you need f18 with a 24mm, you also need f18 with a 100mm. This assumes a theoretical infinity reproduction ratio (non-existent) but works for larger subjects. The turkey or chicken might be at around 1:15 repro ratio so there would be some extra need to stop down, maybe around one stop more with the wide-angle view. The shot does not look more dramatic, it just appears to have a different geometry.

This is a mono repro (the original is in colour, but probably long lost) showing the same supermarket chicken (pre cooked) shot with a 300mm lens on the Fujix GX680, left, then from the same height but a closer position with the 65mm lens (a wide angle). The subject may appear to be cropped larger, but if you study both the chicken and the plate, you'll see it is really the 'same' size end to end. But the whole breast and wing scale looks entirely different, much better value! This appeared with a short article in the pilot edition of Photon web magazine, January 1995.

David

[Greg Beetham]

It's probably just my photograpic "sixth sense" saying that if you move four and a half times closer to the same subject the dof is going to get shallower, but David I'll take your word on the commonality of dof with different focal length lenses at vastly different distances (to get the same repro.) btw the angle of "take" on the subject is quite different, because as you say the tripod was obviously left at the same height, but I think this different angle is contributing a fair amount to the vastly different result.
Greg
ps When you mentioned the Fuji 6X8 that reminded me of all those wonderful MF film systems that used to be in use is pro studios..Rolli, Bronica, Mamiya, Hasselblad...we should have a minutes silence.

[David Kilpatrick]

It's probably just my photograpic "sixth sense" saying that if you move four and a half times closer to the same subject the dof is going to get shallower, but David I'll take your word on the commonality of dof with different focal length lenses at vastly different distances (to get the same repro.) btw the angle of "take" on the subject is quite different, because as you say the tripod was obviously left at the same height, but I think this different angle is contributing a fair amount to the vastly different result.

Try it with a football (soccer ball) or a globe, where the angle of take can not vary at all as it's a sphere. A lot depends on the texture of the surface, a sphere with a moderately coarse consistent texture takes on a more solid appearance; spheres without texture don't benefit much, as they just look like a circle cut out from any distance.

David

[01af]

I explained it in my first ever article for MINOLTA MIRROR (1975 annual), with perspective diagrams ...

That article of yours appeared in the 1976 issue, on page 100ff. It starts with a wide-angle landscape shot showing water, beach, sky, and sun---allegedly taken with an MC W.Rokkor 21 mm 1:2.8 lens but really taken with a non-Minolta lens (Pentax 28 mm if I remember correctly; you've mentioned that story elsewhere before). And the article---great article by the way!---ends with a family shot of David and Shirley on page 108, in their twenties, David with lots of hair and Shirley with less-than-one-year-old baby son Richard on her lap

Wowie zowie David how did you organize those clouds over/behind the cathedral radiating away from it like that?

It even works with dull days if there's a bit of cloud texture. I worked out how lenses like 20mm/17mm enabled a different relationship with the sky - in particular - right at the beginning of my photographic career and I've used it ever since.

Right---you just cannot help getting skies like that with super-wide lenses. It will happen all by itself.

Another function of wide-angle lenses is to make round objects look more spherical. This was taught to me, I didn't work it out for myself but learned it from a top food photographer around 1981. By using a wide lens, I can make a skinny Christmas turkey (or Thanksgiving turkey) look twice its weight.

Hey! I never was aware of that effect before ... even though when thinking about it, it's only natural. Thanks for pointing this out!

For the same subject scale, depth of field stays constant with changes of focal length.

This is true only as a first-order approximation, and accurate enough for practical intents and purposes for standard, telephoto, and super-telephoto lenses (macro lenses, too) but not for wide-angles.

If you need f18 with a 24mm, you also need f18 with a 100mm. This assumes a theoretical infinity reproduction ratio (non-existent) but works for larger subjects. The turkey or chicken might be at around 1:15 repro ratio so there would be some extra need to stop down, maybe around one stop more with the wide-angle view.

Actually, one stop (or so) less with the wide-angle, at less-than-infinite distances. The wider the angle of view, the wider the depth-of-field (when keeping aperture and reproduction ratio constant). But the DOF will change in a complex way. With the same reproduction ratio (or magnification) at the plane of focus (and the same image format and the same sperture, of course), the wide-angle's DOF extending towards the camera will be less (!) than the telephoto's but the DOF extending towards the background will be deeper. So in order to exploit available DOF to the maximum, you'd have to focus at slightly different points within the subject's depth ... which in turn will make the concept of equal magnification a mess (in theory only, of course; in real life you'd just look through the viewfinder, focus, and compose the shot). The gain in the background DOF will exceed the loss of foreground DOF so overall DOF will be wider in the wide-angle shot.

The reason for this is the non-constant magnification across the depth of the field. The magnification at the near border of DOF will be larger than at the far border. And since DOF basically depends on aperture and magnification, the different magnification gradients of wide-angle and telephoto lenses do have a substantial effect on DOF when wide angles of view are involved.

-- Olaf

[David Kilpatrick]

I explained it in my first ever article for MINOLTA MIRROR (1975 annual), with perspective diagrams ...

That article of yours appeared in the 1976 issue, on page 100ff. It starts with a wide-angle landscape shot showing water, beach, sky, and sun---allegedly taken with an MC W.Rokkor 21 mm 1:2.8 lens but really taken with a non-Minolta lens (Pentax 28 mm if I remember correctly; you've mentioned that story elsewhere before). And the article---great article by the way!---ends with a family shot of David and Shirley on page 108, in their twenties, David with lots of hair and Shirley with less-than-one-year-old baby son Richard on her lap

You are right, 1976. Of course it was all produced in 1975 and the annual appeared in December 75. The pix were mainly from 1974 - which is why they chose to use an opening full page shot taken with Pentax 20mm and was also by Shirley not me since I am visible in the photo - but the best full-page reproduction was genuinely from the 21mm f2.8, in monochrome. The problem was that I worked almost entirely in black and white then, and they wanted a colour opening page to fit their plans. The original article was entirely based on b/w, and it did include pix taken on non-Minolta lenses - Soligor 17mm f4, and Komuranon 24mm f2.5. Shirley was still using Pentax/Praktica and even after I had moved to using Minolta, she did not - she switched to Olympus OM instead and did not begin to use Minolta until 1981 when we started with the club.

But MM was always like that. Many not-really-Minolta professionals were featured just for their photography, they might happen to use a Minolta for some of it, but not all. For the record, pix they used in their calendar and on lens boxes from me were all on Minolta. They gave me one year in which to come up with my 'payment' in the form of a sheet of 24 finally selected images which they could use, and everything had to be shot on the kit supplied. It was very clever of them, and partly why I stopped using other cameras much. I wanted all the best pix to be on Minolta.

David