DOF (Depth of Field)

[MJP]

So the bottom line - and all you really need to know - is that DOF is inversely proportional to format size. Note that format size is inversely proportional to the "digital multiplier". The higher the "digital multiplier", the smaller the format and thus the greater the depth of field. Note also that now you can see one of the reasons large format camera users need tilts and swings to get adequate depth of field. With an 8x10 camera you have about 8.5 times LESS depth of field than you do with 35mm for the same image. This also explains why consumer digicams, some of which have sensors 1/6 the size of 35mm film, have such a large depth of field and one of the reasons why it's almost impossible to get blurred backgrounds when using them.

Photo.net

Yes. I'm talking nonsense. Of course, it's why I could never get good bokeh out of the LX5's small sensor.

I'm confused by the output of the DoF calculator though. Shows shallower DoF with the crop format over the full frame.

Edited November 9, 2013 by MJP

[FracturedRabbit]

Not wishing to complicate matters; but depth of field for a given focal length at a given aperture is fixed, irrespective of the size of the sensor. A 50mm lens at F2, for example, will produce a certain depth of field on a medium format sensor. Put that same lens on a "full frame" sensor and the image produced, including the depth of field, will be exactly the same; except the image will be cropped because it is being projected onto a smaller sensor. Put that same lens on a cropped sensor and the image produced, including the depth of field, will be exactly the same; except the image will be cropped because it is being projected onto an even smaller sensor.

What creates the differences in DOF is the fact that wider lenses are used in smaller sensors to produce the same image field of view than a larger sensor camera. So a point and shoot camera might use a 5mm F2 lens to produce and image with the same field of view as a 50mm F2 lens on a medium format camera. So both images look the same in terms of view; but the point and shoot has a much bigger depth of field because (and refer to the Digital Camera diagram earlier in the thread) wider lenses give more depth of field than lenses with a longer focal length.

In summary: A lens set at an aperture will give the same depth of field whichever sensor it is mounted on; it's the field of view generated by different sized sensors that creates the DOF difference.

Not sure that helps at all.....

[MJP]

I think I'll stick to making cheese sandwiches.

[FracturedRabbit]

So the bottom line - and all you really need to know - is that DOF is inversely proportional to format size. Note that format size is inversely proportional to the "digital multiplier". The higher the "digital multiplier", the smaller the format and thus the greater the depth of field. Note also that now you can see one of the reasons large format camera users need tilts and swings to get adequate depth of field. With an 8x10 camera you have about 8.5 times LESS depth of field than you do with 35mm for the same image. This also explains why consumer digicams, some of which have sensors 1/6 the size of 35mm film, have such a large depth of field and one of the reasons why it's almost impossible to get blurred backgrounds when using them.

Photo.net

Yes. I'm talking nonsense. Of course, it's why I could never get good bokeh out of the LX5's small sensor.

I'm confused by the output of the DoF calculator though. Shows shallower DoF with the crop format over the full frame.

You couldn't get limited DOF out of the LX5's 5mm focal length lens...

Bokeh is of course a related but different subject. Limiting the DOF will give you out of focus areas; but that is no guarantee that you will get good bokeh. Some lenses produce bokeh that looks atrocious!

[FracturedRabbit]

I think I'll stick to making cheese sandwiches.

Pickle with mine please.

[MJP]

I think I'll stick to making cheese sandwiches.

Pickle with mine please.

It's bad Rabbit. I've gone so thick recently I near cut my left thumb off the other day just slicing a tomato.

Branston is unavailable in Issan. Sadly.

[MJP]

So the bottom line - and all you really need to know - is that DOF is inversely proportional to format size. Note that format size is inversely proportional to the "digital multiplier". The higher the "digital multiplier", the smaller the format and thus the greater the depth of field. Note also that now you can see one of the reasons large format camera users need tilts and swings to get adequate depth of field. With an 8x10 camera you have about 8.5 times LESS depth of field than you do with 35mm for the same image. This also explains why consumer digicams, some of which have sensors 1/6 the size of 35mm film, have such a large depth of field and one of the reasons why it's almost impossible to get blurred backgrounds when using them.

Photo.net

Yes. I'm talking nonsense. Of course, it's why I could never get good bokeh out of the LX5's small sensor.

I'm confused by the output of the DoF calculator though. Shows shallower DoF with the crop format over the full frame.

You couldn't get limited DOF out of the LX5's 5mm focal length lens...

Bokeh is of course a related but different subject. Limiting the DOF will give you out of focus areas; but that is no guarantee that you will get good bokeh. Some lenses produce bokeh that looks atrocious!

You could. But it looked crap. Only really worked in macro.

Edited November 9, 2013 by MJP

[FracturedRabbit]

So the bottom line - and all you really need to know - is that DOF is inversely proportional to format size. Note that format size is inversely proportional to the "digital multiplier". The higher the "digital multiplier", the smaller the format and thus the greater the depth of field. Note also that now you can see one of the reasons large format camera users need tilts and swings to get adequate depth of field. With an 8x10 camera you have about 8.5 times LESS depth of field than you do with 35mm for the same image. This also explains why consumer digicams, some of which have sensors 1/6 the size of 35mm film, have such a large depth of field and one of the reasons why it's almost impossible to get blurred backgrounds when using them.

Photo.net

Yes. I'm talking nonsense. Of course, it's why I could never get good bokeh out of the LX5's small sensor.

I'm confused by the output of the DoF calculator though. Shows shallower DoF with the crop format over the full frame.

On the plus side; the large DOF does make the LX5 excellent for macro.

[skippybangkok]

So the bottom line - and all you really need to know - is that DOF is inversely proportional to format size. Note that format size is inversely proportional to the "digital multiplier". The higher the "digital multiplier", the smaller the format and thus the greater the depth of field. Note also that now you can see one of the reasons large format camera users need tilts and swings to get adequate depth of field. With an 8x10 camera you have about 8.5 times LESS depth of field than you do with 35mm for the same image. This also explains why consumer digicams, some of which have sensors 1/6 the size of 35mm film, have such a large depth of field and one of the reasons why it's almost impossible to get blurred backgrounds when using them.

Photo.net

Yep... them huge 4x5 inch formats have even bigger problems with DOF.

Don't want to go into the maths of it, but i saw it with my own eyes. I was shooting FX film using a 105mm lens, would get for the shrimp close ups only the eyes and if lucky claws in focus at f54 ( and huge amount of strobe power ). Friends were shooting 105mm lens using digital DX format, and getting more in the same shot than i was ( more in focus ). Was the only reason i switched in those days to digital, and i always loved Velvia over the results of the D70 in those days.

Just bought D610.... first time i feel digital is approximating film

Edited November 9, 2013 by skippybangkok

[MJP]

So the bottom line - and all you really need to know - is that DOF is inversely proportional to format size. Note that format size is inversely proportional to the "digital multiplier". The higher the "digital multiplier", the smaller the format and thus the greater the depth of field. Note also that now you can see one of the reasons large format camera users need tilts and swings to get adequate depth of field. With an 8x10 camera you have about 8.5 times LESS depth of field than you do with 35mm for the same image. This also explains why consumer digicams, some of which have sensors 1/6 the size of 35mm film, have such a large depth of field and one of the reasons why it's almost impossible to get blurred backgrounds when using them.

Photo.net

Yes. I'm talking nonsense. Of course, it's why I could never get good bokeh out of the LX5's small sensor.

I'm confused by the output of the DoF calculator though. Shows shallower DoF with the crop format over the full frame.

On the plus side; the large DOF does make the LX5 excellent for macro.

Involuntarily gave my LX5 away. Thinking of a replacement. Maybe X20. Dunno.

Cheese Gromit?

[FracturedRabbit]

I have a mint LX5 I can sell you. Comes with free pickles.

[MJP]

I have a mint LX5 I can sell you. Comes with free pickles.

You know what I'm like for new gadgets Rabbit . . .

[Tywais]

Bokeh is of course a related but different subject. Limiting the DOF will give you out of focus areas; but that is no guarantee that you will get good bokeh. Some lenses produce bokeh that looks atrocious!

That is a good point and something that may be confusing it for me as I keep reading large sensors give better bokeh and I may have been equating DOF (focus range) with it. And from this article, I'm not alone.

Bokeh Vs DOF — The Difference Between The Two

Bokeh and depth of field, both the techniques help the photographers in creating beautiful photographs. In the approach of photographing at lower f-numbers, the distinction between depth of field and bokeh vanishes and the hobbyists and enthusiasts often end up using the terms bokeh and DOF interchangeably. To photograph the aesthetics of the subject and the background, one should be clear about what DOF and bokeh stand for. To effectively use the two techniques, let’s have a quick view at depth of field, bokeh and the differences between the two.

What Is Depth Of Field

The depth of field refers to the area of sharp focus in a photograph. When taking a photograph, sometimes it may be desirable to have the entire image sharp and at other times you may be interested in focusing only a small portion of the scene. You can easily achieve the desired effect by tuning the camera to aperture priority mode for either high depth of field or shallow DOF.

APNPhotographyschool

Good examples of the difference in the below article:

Photography 101: Depth of Field & Bokeh

Depth of Field/DOF is the term used to describe the area in your image that is “Acceptably Sharp” (read “in focus”).

Bokeh is the term used to describe the out of focus area in an image – however, simply being out of focus is not enough to qualify as bokeh – there must be a ‘uniformity’, a ‘pleasing’ aspect – For an image to have ‘nice bokeh’ (© Flickr) there must be some kind of aesthetic appeal…

See why I had such an issue pinning this one down?

What Is Bokeh

Bokeh is the aesthetic quality of blur in out of focus areas of the image. Bokeh is the terminology used for defining the quality of blur achieved at shallow depth of field. It refers to the quality of blurred imagery complemented by circular discs of light rendered by out-of-focus points of light.

Picturesbyjay

[Tywais]

An interesting read (pdf format) that also states (empirically) that DOF is not dependent on focal length (and why I'm getting a headache). Seems it is a matter of understanding what you are seeing as opposed a paradigm shift in the technological understanding. Worth a read.

There is a long-standing myth in photography that focal length has an impact on the depth of field in your scene. I know this myth is long-standing because it's what I was taught and what I have, in turn, been teaching. In fact, the previous three editions of this book included this very myth. However, with a simple experiment, you can demonstrate that focal length has no impact on actual depth of field.

Article (pdf) here - Complete Digital Photography, 4th Edition, by Ben Long

[FracturedRabbit]

More on bokeh: http://www.stevehuffphoto.com/2010/02/11/what-is-bokeh/

[Tywais]

More on bokeh: http://www.stevehuffphoto.com/2010/02/11/what-is-bokeh/

I like his stuff and a good site. Always very informative.

[FracturedRabbit]

I read somewhere that imperfect lenses can produce interesting bokeh. I have a $20 Russian lens which is as imperfect as they come and it certainly produces riotous bokeh; although not sure this qualifies as "good".

[MJP]

I read somewhere that imperfect lenses can produce interesting bokeh. I have a $20 Russian lens which is as imperfect as they come and it certainly produces riotous bokeh; although not sure this qualifies as "good".

I'll try that with my Jupiter 11A. It's rear element has a bubble in it.

[FracturedRabbit]

I'll take your bubble, and raise it with scratches front and rear, haze, and what looks like the contents of well-used handkerchief rammed between the first and second elements.

[MJP]

I'll take your bubble, and raise it with scratches front and rear, haze, and what looks like the contents of well-used handkerchief rammed between the first and second elements.

I should've brought them with me but the overall weight was too much for luggage. Got CZJ DDR 50/f1.8 Electric and DDR 135/f3.5 too. Good for Bokeh. Helios 44M-4 mad for it.

Edited November 9, 2013 by MJP

[Guest]

As this is an technical discussion.

Is there a physical necessity to have a lense between the view and the sensor?

If the lense is taken out of equation, then the DOF would be full as the sensor would be simply register the light.

If the sensor is flat, then the image angle would be very short.

But if the lense would be rounded, then it could take wider angel photos. That's not today's technology but I guess that's where we are heading towards.

[MJP]

Can we start making some of these multiple choice questions?

My brain just died.

[Dancealot]

With this experiment at Chester's i tried to exclude the other coins from the one I was focusing on.

Step 1 succes

Step 2 increase FL..

Step 3 made me realise I couldn't exclude the other coins while increasing the aperture..

I wanted to single out the last coin but I couldn't whitout invloving the others in front.

[FracturedRabbit]

As this is an technical discussion.

Is there a physical necessity to have a lense between the view and the sensor?

If the lense is taken out of equation, then the DOF would be full as the sensor would be simply register the light.

If the sensor is flat, then the image angle would be very short.

But if the lense would be rounded, then it could take wider angel photos. That's not today's technology but I guess that's where we are heading towards.

There is no need for a lens. The clue to this fact lies in the name "camera" which is Latin for "vaulted room". The first cameras were called camera obscura (obscura=darkened) and were dark rooms or enclosures with a tiny hole in one wall. The image was then displayed on the opposite wall.

The concept lives on nowadays in pinhole cameras and there is a little more history in my review of such a camera here: http://www.pattayadays.com/2013/09/zero-image-pinhole-camera/

You can use a pinhole lens on a digital camera too: http://www.pattayadays.com/2011/04/a-holy-day/

[astral]

Single focal length lenses often have a DOF indicator on the focusing ring

Indicating the range of focus for a particular setting.

f22 I f22

This can be used to determine the setting for the hyperfocal distance

where the maximum DOF is achieved

Not so easy on zoom lenses which are now the default

.

[Fiddlesticks]

Single focal length lenses often have a DOF indicator on the focusing ring

Indicating the range of focus for a particular setting.

f22 I f22

This can be used to determine the setting for the hyperfocal distance

where the maximum DOF is achieved

Not so easy on zoom lenses which are now the default

.

I find this easier to use. I hope this attachment works! ! !

hyperfocal-distance-charts-2013-0-03-large.pdf

[Guest]

As this is an technical discussion.

Is there a physical necessity to have a lense between the view and the sensor?

If the lense is taken out of equation, then the DOF would be full as the sensor would be simply register the light.

If the sensor is flat, then the image angle would be very short.

But if the lense would be rounded, then it could take wider angel photos. That's not today's technology but I guess that's where we are heading towards.

There is no need for a lens. The clue to this fact lies in the name "camera" which is Latin for "vaulted room". The first cameras were called camera obscura (obscura=darkened) and were dark rooms or enclosures with a tiny hole in one wall. The image was then displayed on the opposite wall.

The concept lives on nowadays in pinhole cameras and there is a little more history in my review of such a camera here: http://www.pattayadays.com/2013/09/zero-image-pinhole-camera/

You can use a pinhole lens on a digital camera too: http://www.pattayadays.com/2011/04/a-holy-day/

I actually meant that there would not be any lense nor single point of path where the light would get in to the sensor. Instead each of the pixel on the sensor would act as it's own collector of light with no optics involved. However there should likely need to be a mesh on top of the sensor, which would block the scattered light to enter to each pixel on the sensor.

This is pretty much what I tried to say about the end product. Every single pixel can be in focus, and in this example each area can be made to be the focus point, while other pixelgroups will get defocused, if wanted.

https://refocus.nokia.com/refocus/cUo16EfpzpGDSqVO/image

That pinhole camera is great btw

[Tywais]

Another article on how to make a digital pin hole camera. Has a good explanation of the optics involved. How to Take Pinhole Photos ...

World's largest photo taken with a pin hole camera - The Great Picture

I may have to make one and try. I have tools at the lab to make incredibly small holes. I actually have laser cut 50 micron and 10 micron precision pin holes already. 100 microns is the size of the average human hair.

[FracturedRabbit]

This delightfully insane guy makes pinhole cameras out of beer cans, and then leaves them to expose for six months!

[jack2964]

I do have a general understanding of how manipulating aperture and/or focal length will alter the amount of DoF.

So far this knowledge has served me well until this picture below:

I don't know why the subject's left foot is out of focus but not the right.

The distance of either foot to my camera should be nearly equal and I expect both to be either in or out of focus.

I am stumped, what do you think happened here?