Linked Questions

1
vote
0answers
112 views

What causes swirling in bokeh? [duplicate]

The East German antique lens, Zeiss Biotar 75mm, is famous for producing a swirling, water-like bokeh as illustrated in the photo below: What optical materials and/or design cause this effect, which ...
2
votes
0answers
54 views

What creates a calisson-like shaped light bokeh ? How to craft this aspect of the bokeh? [duplicate]

What creates a calisson-like shaped light bokeh such as this one (made with Arri signature T/1.9) ? The further from the center the more present are the angles, why ? Another lens (Zeiss Supreme T/1....
49
votes
3answers
8k views

What image-quality characteristics make a lens good or bad?

When reading lens reviews on the Internet, I often find subjective statements about the image quality that a lens produces, such as "good contrast" or "sharp". The problem is that I don't think I am ...
19
votes
4answers
14k views

What swirly bokeh technique is this and how can I achieve it?

What is the technique used to capture this image? How can the result be achieved? I know that it can be achieved in a digital darkroom but how can I replicate the effect straight out of the camera?
20
votes
2answers
6k views

How to create the type of lighting that is used in many of Elena Shumilova's pictures?

Elena Shumilova posts a number of photos online. Many of her images have this sort of signature airy, soft, glowing lighting. This is good example. How would I go about recreating this type of ...
14
votes
2answers
2k views

What are the use cases of a Petzval lens?

I am interested to know when would one use these lenses and what are they best suited for?
8
votes
2answers
9k views

What does “Flat Field Focus” mean?

Looking at lenses, specifically sigma macro lenses, I noticed that it had a ""Flat Field" front lens element". What does this mean? And how is it different to the norm?
1
vote
3answers
2k views

Do lens hoods need to be matched to focal length?

Is it true that not all generic lens hoods work on all lenses (provided the filter diameter matches, of course)? I read that the focal length plays a role in it - but I cannot find such readings on ...
4
votes
2answers
2k views

How to prevent “cats eye” bokeh?

What steps could someone take in order to keep their bokeh balls as circular as possible? I know stepping down the lens aperture will help. Are there any other suggestions? Would using the lens hood ...
4
votes
3answers
262 views

How is a lens's bokeh determined by its construction?

I'm buying a new lens and am interested in determining how the out-of-focus effects will turn out with it. How is a lens's bokeh determined by its construction, and can one get an approximate idea of ...
4
votes
1answer
575 views

Do lenses have focal planes or focal spheres/ellipsoids?

The title says it pretty much all. I'm asking this because I find myself always using the focus point in the center, and after I focused, I rotate my camera to make the framing right. However, if ...
1
vote
1answer
292 views

What causes this 'bokeh crop' effect?

I've seen this effect before & not thought much about it, but I was trying out some experiments with a string of xmas lights & short DoF & noticed that sometimes I can get circular bokeh ...
2
votes
3answers
244 views

In photo taken with a prime lens, what is the cause of the “zoomed” bokeh appearance?

This image was taken with a Vivitar 24/2 (Kiron) prime lens. The lens is sharp. The focal plane is reasonably flat, and there is barrel distortion. The bokeh balls have an oval shape in which the ...
1
vote
1answer
172 views

How wide does the front element of a lens have to be, given the focal length and the aperture?

Clearly, a lens with focal length F and aperture 1/f has to be at least F/f mm wide. Maybe a little more to accommodate the angle of view. However, lenses tend to have wider front elements than F/f. ...
0
votes
1answer
227 views

Why does my depth of field look like it’s swirling?

I’m sure this is an illusion. Maybe it’s just me, but to my eyes the out of focus areas look as if they’re swirling or distorted, like if you took the photo with a fisheye lens or something like that. ...