PDA

View Full Version : Lens shade question



chris_4622
15-Nov-2018, 04:26
Hi,

Is there a difference when using a very efficient lens shade that was made for infinity focus, at distances that are close to 1:1? Does the shade become less efficient, stay the same or start to vignette?

thanks,
chris

Alan9940
15-Nov-2018, 07:27
I don't use lens shades on my LF cameras, but my guess is that since a lens shade depth and size are related to the film format and focal length of the lens there would be no difference. I believe where you'll get possible vignetting from the shade is when you employ camera movements.

Jim Jones
15-Nov-2018, 08:14
A shade that is efficient when focused at infinity is less efficient when focused very closely on the same lens because the lens is covering a narrower field of view. However, in practical photography there are more important considerations such as the shade blocking light or casting shadows on the subject.

chris_4622
15-Nov-2018, 08:52
A shade that is efficient when focused at infinity is less efficient when focused very closely on the same lens because the lens is covering a narrower field of view. However, in practical photography there are more important considerations such as the shade blocking light or casting shadows on the subject.

Okay that makes sense. Thanks.
When I made the shade I set the camera at infinity thinking (without any real knowledge) that I would be okay at closer distances. I am well aware of using movements with a fixed efficient shade and how quickly it vignettes. As for blocking light or casting shadows in my case it's not a concern for the portraits I've been making. I need to use the shade for some lighting schemes where the source is faced towards the lens.

Leszek Vogt
16-Nov-2018, 00:43
How about Dinkum shade ?....at least you could adjust it.

Les

Jim Andrada
24-Nov-2018, 22:48
I always use a bellows type lens shade and adjust it after focusing.

Mark Sawyer
25-Nov-2018, 11:49
A shade that is efficient when focused at infinity is less efficient when focused very closely on the same lens because the lens is covering a narrower field of view. However, in practical photography there are more important considerations such as the shade blocking light or casting shadows on the subject.

Nit-picking here, the lens is covering the same field of view, but with a larger image circle due to bellows extension, and the narrower field of view is cropped from that larger image circle. Vignetting is less likely at greater bellows extension because of that larger image circle. Agreed that the big issue is whether the lens shade shades the lens from a harsh light source that can cause flare. That's what lens shades do, regardless of distances. AR lens coatings can also be important in these situations.

Square compendium shades might be the best solution for the most demanding, but for all practical purposes, if it shades the lens, it shades the lens. Many of us just use the dark slide to shade the lens in the field.

Mark Sawyer
25-Nov-2018, 11:53
I need to use the shade for some lighting schemes where the source is faced towards the lens.

Something between the source and the lens.

Jim Andrada
26-Nov-2018, 21:33
Hopefully it's aimed diagonally toward the lens and not dead staright into the lens.

If diagonally, as in for example a hair light aimed from the back, then a lens shade should be adjusted to keep the direct light out of the lens. If this isn't possible, then as Mark suggested, something between the light and the lens - maybe a mask of some kind or "barn doors" on the light source to shade the lens. For outdoor work, you can use a large flat object on a light stand to shield the lens.