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02-06-2015, 07:54 AM   #16
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QuoteOriginally posted by Oldbayrunner Quote
Please, don't make me watch another moronic video..... go outside and try it.

As you move closer to your subject, the lens barrel has to extend further from the film plane, to keep the subject in focus, and the circles of confusion get bigger at the film plane, they overlap more and the OOF areas become less distinct. That's just optical physics. I'm sure someone will correct me if I'm wrong.

02-06-2015, 08:18 AM   #17
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QuoteOriginally posted by Oldbayrunner Quote
Selective quotation is selective... norm is actually right and Mike, in that video is talking about something slightly different.
You misunderstand a few things...

---------- Post added 02-06-15 at 10:19 AM ----------

QuoteOriginally posted by normhead Quote
Please, don't make me watch another moronic video..... go outside and try it.
Mike is a very good photographer and what he explains in the video is right, but has nothing to do with bokeh and what you were guys talking about. He explaining something else, slightly different.

Last edited by mrNewt; 02-06-2015 at 08:30 AM.
02-06-2015, 08:23 AM   #18
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About Sensors size and depth of field.

See here: https://people.rit.edu/andpph/text-depth-of-field.html

excerpt:" So if you make the same size print and shoot with a lens that gives you the same view and you use the same aperture, if you halve the format size you double the DOF, if you double the format size you halve the DOF".
02-06-2015, 08:27 AM   #19
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QuoteOriginally posted by Sagala Quote
About Sensors size and depth of field.

See here: https://people.rit.edu/andpph/text-depth-of-field.html

excerpt:" So if you make the same size print and shoot with a lens that gives you the same view and you use the same aperture, if you halve the format size you double the DOF, if you double the format size you halve the DOF".
The phrase 'same view' means you've altered the subject distance, Sagala.

You can go to a DoF calculator and see for yourself. :-)

02-06-2015, 08:37 AM   #20
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QuoteOriginally posted by Sagala Quote
About Sensors size and depth of field.

See here: https://people.rit.edu/andpph/text-depth-of-field.html

excerpt:" So if you make the same size print and shoot with a lens that gives you the same view and you use the same aperture, if you halve the format size you double the DOF, if you double the format size you halve the DOF".
And it's easy to confirm.... Take an image with ruler in it vertical to the sensor plane and something to focus on in the middle of the ruler. Take the image with you 50 and 35 at the closest your 50 will focus. The 50 will be your FF image. When I did it, I got roughly twice as much DOF from the 35 image cropped to the same size as the 50 image. It's a pretty easy demo, and much more convincing than a DoF calculator.

Last edited by normhead; 02-06-2015 at 09:05 AM.
02-06-2015, 08:55 AM   #21
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Here is an excellent article treating of the matter under discussion.

Blog @ BorrowLenses
02-06-2015, 09:06 AM   #22
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Thanks for that.
02-06-2015, 09:14 AM   #23
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A lot of guys forget one thing... 2.8 on crop sensor is NOT actually 2.8. When you do the equivalency on the focal length, YOU MUST apply the same equivalency on your aperture.
A 2.8 50mm is equivalent to a 4 75mm on a 1.5 crop sensor. And that's why your "bokeh" is not as "creamy" as on the FF (or better said your DoF is different)!


Last edited by mrNewt; 02-06-2015 at 10:29 AM.
02-06-2015, 09:22 AM   #24
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QuoteOriginally posted by Newtophotos Quote
I’ve often seen it said that full frame provides better bokeh (or depth of field) than APS-C.
Lesson 1:
Bokeh is not DoF is not Background blur. Three completely different concepts.
  1. Bokeh is purely your aesthetic opinion and can not be measurbated at all. A smartphone can have very pleasing bokeh, while a very fast FF lens can have shitty bokeh.
  2. DoF is easy to calculate but not intentionally the topic of most discussions.
  3. Background blur is loosely related to DoF but can be smaller with more DoF or larger with more DoF as it takes distances between subject and background into account (which primitive DoF calculations completely ignore).
If you encounter people who mix this up (e.g. talk about "the bokeh effect" or "DoF" all the time), they dont have a clue.
02-06-2015, 09:23 AM   #25
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The actual quality of your bokeh is going to be dependent, not on your sensor size, but on the lens. If you shoot an FA 77 on APS-C, it will have the same appearance to out of focus areas as on full frame. It is just that on full frame, you see more out of focus edges than you do on APS-C, where they are cropped out.

What the others have said is true. How much depth of field you have is dependent on focal length, aperture and distance to subject.

This is the 55 at f2 on APS-C.



This is the DA *55 shot at f2.8 on iso 400 color film.



I don't know that there are any conclusions you can draw. I feel like if you are careful you can get decent narrow depth of field with APS-C, but certainly full frame will be more narrow. The quality of the background should be about the same however.
02-06-2015, 09:58 AM   #26
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QuoteOriginally posted by normhead Quote
Please, don't make me watch another moronic video..... go outside and try it.
I'm very adept at achieving what bokeh I want both outside or inside...That video was not just for your viewing pleasure or displeasure. there are other members such as the OP that might find benefit. My quoting you was because in the case of closeness it is not necessary at all times to move closer. One would need to move closer with a wide angle lens using a wide aperture but one can still obtain bokeh by utilizing a telephoto lens at it's wider aperture moving farther away. I used this video to illustrate as Mike increased his focal length moving farther away maintaining the same focal area the background becoming more blurred to the point of being unrecognizable. Hence why I stated Not Necessarily to needing to get closer as your blanket statement indicates.. Distance is only one part.

One perhaps may find this too moronic, if so no need to read., The OP and others however might find value in reading this excellent article that distinctly addresses the OP's original post. http://www.smt.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/CLN_35_Bokeh_EN/$File/CLN35_Bokeh_en.pdf

QuoteOriginally posted by normhead Quote
As you move closer to your subject, the lens barrel has to extend further from the film plane, to keep the subject in focus, and the circles of confusion get bigger at the film plane, they overlap more and the OOF areas become less distinct
As in less blurred?

Doesn't this sort of contradict this?

QuoteOriginally posted by normhead Quote
The closer you are, the smoother your out of focus areas will be.

Last edited by Oldbayrunner; 02-06-2015 at 11:51 AM.
02-06-2015, 12:30 PM   #27
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QuoteOriginally posted by Oldbayrunner Quote
I'm very adept at achieving what bokeh I want both outside or inside...That video was not just for your viewing pleasure or displeasure. there are other members such as the OP that might find benefit. My quoting you was because in the case of closeness it is not necessary at all times to move closer. One would need to move closer with a wide angle lens using a wide aperture but one can still obtain bokeh by utilizing a telephoto lens at it's wider aperture moving farther away. I used this video to illustrate as Mike increased his focal length moving farther away maintaining the same focal area the background becoming more blurred to the point of being unrecognizable. Hence why I stated Not Necessarily to needing to get closer as your blanket statement indicates.. Distance is only one part.

One perhaps may find this too moronic, if so no need to read., The OP and others however might find value in reading this excellent article that distinctly addresses the OP's original post. http://www.smt.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/CLN_35_Bokeh_EN/$File/CLN35_Bokeh_en.pdf

As in less blurred?
No, as in more blurred.

QuoteQuote:
Lesson 1:
Bokeh is not DoF is not Background blur. Three completely different concepts.
Bokeh is purely your aesthetic opinion and can not be measurbated at all. A smartphone can have very pleasing bokeh, while a very fast FF lens can have shitty bokeh.
DoF is easy to calculate but not intentionally the topic of most discussions.
Background blur is loosely related to DoF but can be smaller with more DoF or larger with more DoF as it takes distances between subject and background into account (which primitive DoF calculations completely ignore).
If you encounter people who mix this up (e.g. talk about "the bokeh effect" or "DoF" all the time), they dont have a clue.
Why... because you say so?

I would agree that some people might like really busy bokeh.. so somewhat subjective... but unrelated? pffft....

Take the same studio set at ƒ2.8, ƒ4, and ƒ8. I guarantee you, the bokeh will change with the ƒ-stop. Hardly unrelated.

QuoteQuote:
If you encounter people who mix this up (e.g. talk about "the bokeh effect" or "DoF" all the time), they dont have a clue.
Please put me on your ignore list, I don't have a clue apparently in your opinion, and that's fine with me.

Last edited by normhead; 02-06-2015 at 12:38 PM.
02-06-2015, 12:39 PM - 1 Like   #28
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QuoteOriginally posted by HavelockV Quote
Bokeh is not DoF is not Background blur. Three completely different concepts.
"Bokeh" DOES refer to the background and foreground blur (out of focus areas)... and background/foreground blur is depended on DoF and subject distance... What are you reading!? The quality or rather said the look (since its quality depends on preference) of the "bokeh" is however, subjective.

The word comes from Japanese language, which literally translates as “blur”.

Bokeh = background and foreground blur.
DoF = area that your subject tends to be in focus and NOT blurred.
"Depth of field is the amount of distance between the nearest and farthest objects that appear in acceptably sharp focus in a photograph. A preferred selection Depth of field ("DOF") in a focused subject in an image can be quite subjective"

Last edited by mrNewt; 02-06-2015 at 12:53 PM.
02-06-2015, 12:56 PM   #29
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You might also want to check this comparison from the Amateur Photographer. It's an old article, but the experiments undertaken are still relevant today

Canon EOS 7D vs Canon EOS 5D Mark II (APS-C vs full frames) - Page 3 of 7 - Amateur Photographer
02-06-2015, 01:41 PM   #30
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QuoteOriginally posted by normhead Quote
No, as in more blurred.
Thx for clarifying that.


Bokeh – properties of blurriness H.H. Hass - Zeiss lens division
RE;
QuoteOriginally posted by HavelockV Quote
Bokeh is not DoF is not Background blur.
A composition parameter which can help us to achieve this objective is the adjustment of the blurring in front of and behind the main subject by a suitable combination of aperture, focal length and taking distance. A blurred background frees the main subject from distracting unimportant details and increases the three-dimensional illusion of the picture. Blurred parts of the picture can also be decorative and play a very important part in the composition of the picture.
QuoteOriginally posted by HavelockV Quote
Bokeh is purely your aesthetic opinion and can not be measurbated at all. A smartphone can have very pleasing bokeh, while a very fast FF lens can have shitty bokeh.
In spite of the subjective nature of the matter we nevertheless want to attempt to remain faithful to the style and character of our technical articles by describing bokeh with some numbers. Of course, this cannot be done on very simple scales, for example, “a grade 5.5 bokeh“, because blurring always depends on a large number of parameters. But figures can help us to improve our understanding of connections.
All the parameters listed here influence the phenomena outside the focal plane:

Picture format

Focal length

f-number

The camera-to-subject distance

Distance to the background or the foreground

Shapes and patterns of the subject

Aperture iris shape

Aberrations of the lens

Speed of the lens

Foreground/background brightness

Colour
It is therefore not surprising that one often hears different and sometimes contradictory judgements about the bokeh of many lenses. Undue generalisations are all too often drawn from single observations.
Many effects are attributed to the lens even though they are mainly caused by the subject in front of the camera. Differences between lenses are often very marginal but are then grossly exaggerated.
QuoteOriginally posted by HavelockV Quote
DoF is easy to calculate but not intentionally the topic of most discussions.
Prey tell share with us those easy calculations of yours. And I don't see you mentioning this.

If we think of conditions where the depth of field stretches from the focus distance into infinity, then it becomes clear that we may have been a bit too naive when talking about doubling or halving the depth of field. Infinite distances can neither be doubled nor divided in two.
But the same rules apply in the format comparison for the hyperfocal distance, the shortest focus distance where the depth of field reaches infinity. We can easily understand this with the help of our object-side light cones again:
A light cone coming from infinity and entering the lens is a bundle of parallel beams and its angular aperture is 0°. Its diameter is the same as the diameter of the entrance pupil. The hyperfocal distance is therefore the distance where the acceptable "object-side circle of confusion diameter" is as large as the entrance pupil.
And once again the rule applies that the smaller sensor format has the smaller entrance pupil if it has the same angular field and the same aperture. The acceptable object-side circle of confusion is therefore already in smaller object fields, meaning it is reached at a shorter distance.

At this point we should make an exception and use a few formulas, because they are the most important ones of the whole topic...

So do you know and use these formulas?

QuoteOriginally posted by HavelockV Quote
Background blur is loosely related to DoF
What are you smoking

I don't know or care where you got this information but I would suggest your boning up a little more using more accurate information.

Last edited by Oldbayrunner; 02-06-2015 at 01:50 PM.
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