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Messages - PavelR

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46
Lenses / Re: 50mm upgrade or 85mm coverage?
« on: December 12, 2012, 09:55:21 AM »
Having FF with 35L, 50 1.5 and 135L, I'm thinking in:
1) selling the 50mm 1.4 and buy the 50L
2) buying the Sigma 85 1.4
3) buying 85L (more difficult due to the money involved)

Anyone had a similar debate?
Having 1.3x with the same lenses and question some time ago.
I owned 85/1.8 and upgraded to S 85/1.4.  (C1.8 = too much violet fringing and inconsistent AF)

47
EOS Bodies / Re: Memory Cards--What is the absolute best?
« on: December 11, 2012, 05:45:23 AM »
Is there any card with better parameters than Lexar 1000x 128GB?
(http://www.lexar.com/products/lexar-professional-1000x-compactflash-card?category=77)

48
Canon General / Re: Is it worth it...for me?
« on: December 02, 2012, 09:17:02 AM »
Don't worry about whether someone else will notice differences in the finished results - better equipment is more enjoyable to use (some of us like the actual process of *using* a camera) and if you find a camera and/or lens more enjoyable to use you will likely end up taking better photos anyway.

If you don't know someone with a FF camera, do what I did and rent one (ditto lenses you're interested in); doing so isn't exactly free, but you may end up saving money (or not!); and there's no substitute for hands-on experience.

One last thing - if you like portraits with blurred background, consider going longer (esp. if you end up FF); 135L is not only fantastic in its own right, but considerably less expensive than 50L or 85L.  Or try a good zoom such as Canon's 70-200 f/4 IS (or a 70-200 2.8 - needn't be Canon).  If you want 85, consider the Sigma.

Have fun!
+4 ;-)
enjoying, longer FL, 135/2, 85/1.4

49
Reviews / Re: Review - Canon EF 100 f/2.8L IS Macro
« on: November 27, 2012, 09:29:45 PM »
Thank you, brad-man and infared, for the information.

50
Reviews / Re: Review - Canon EF 100 f/2.8L IS Macro
« on: November 27, 2012, 11:44:28 AM »
Anybody here owning 100L and 135L?
Comparison of my copies make clear winner 135 @ F2.8. Do you have any opposite experience?
(Of course comparison is done on NON-macro shots...)

I have them both and love them both, but I don't think I've ever made a direct comparison (I probably have a slight bias in favor of the 135 but I'm not sure I have anything to back it up).  In what way(s) do you think the 135 is the "clear winner"?
I used it several times in portrait shooting occasions and the images are visibly softer comparing it with the result from 85/1.4, 135/2, 200/2 (all at F 2.8 [I usually use F 2.0-2.8]), thus I asked the question, whether my copy of 100L is not under the average... (Other than portrait images with focus distance about 15-20 meters are quite OK.) (+ in direct comparison with Nikon 105 VR images taken with my 100L looks pretty softer too - especially till F4 of contrasty jewelry with small details...)

51
Reviews / Re: Review - Canon EF 100 f/2.8L IS Macro
« on: November 27, 2012, 09:49:41 AM »
Anybody here owning 100L and 135L?
Comparison of my copies make clear winner 135 @ F2.8. Do you have any opposite experience?
(Of course comparison is done on NON-macro shots...)

52
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 06:43:05 PM »
Another example: shooting straight en face with 50/2.8 both eyes are sharp pretty the same, but shot with 300/2.8 = it is easy to say which eye was focused on.
Sure it is, if you are shooting at the same distance - in that case, if the face fills the 300mm frame, it's only a small portion of the 50mm shot, and if it fills the 50mm frame then your 300mm shot is only showing the eyes (or would be, if you weren't closer than the MFD of the lens). But if you're 6 times further away at 300mm compared to 50mm, so the framing is the same, then the DoF is the same

It always has and always will be difficult to convince people that what they think they see is not in fact true (even with explanations and examples).
Through the filter of our own misconceptions, everyone else's statements are part of the blurry background.
I meant the same framing, of course.

My opinion was determined by looking on my photos, thus your simplified theories are not able to reverse my mind.

53
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 06:11:22 PM »
If you crop just the tower from both images, and view them at the same size on the screen, they will look identical.  That means the blur is identical. 

Examples from http://toothwalker.org/optics/dof.html.

100mm f/4:


28mm f/4:


The car to the right of the subject has more blur with the 100mm lens than with the 28mm lens, right? 

 

Wrong. Same blur. That's the case even in your extreme example.

I'm not saying it looks the same, the tower and car do look more blurred with the longer focal lengths. Like I said, it's good illusion.
Thx for the link - there is deep explanation we all agree with (I suppose).
And our different view on the last posts is nicely summed up by paragraph:
---
This is true when we speak of the absolute blur. The absolute blur is given by the blur disk diameter of a point in the background, such as the highlight reflections off the cars in the street. However, when we speak of the relative blur we must relate the blur disk size to the "image magnification" of the background. And that magnification is larger with the 100-mm lens too. As a matter of fact, the relative blur of the backgrounds is identical.
---

54
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 05:30:32 PM »
Exactly.  Your eyes are being fooled. The blur is the same. That it doesn't look that way is an illusion. But...it's a good illusion.
I think that we need to define "background blur" now, because it does not look like the same COC at 200mm and 400mm.
And what about my extreme examples in the previous post? Do you still call it: "my eyes are fooled"?

Background blur is already well defined, you are not using it in its common context. As I said, the towers are both blurred exactly the same, below is an image where I have made the tower the same size from the 200 and 400 shots, they are exactly the same.

 You are not referring to how blurred an object is, you are referring to how big objects at different distances are in relation to each other. That is perspective, not depth of field. For a same sized subject and aperture a longer lens shot from further away will give you a bigger apparent background object, hence the illusion of it being more blurred.
You did the operation which affects DOF - you changed magnification - look at: http://en.wikipedia.org/wiki/Depth_of_field

55
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 05:06:07 PM »
No, look again, the actual blur of the tower is the same, BUT the tower is much bigger with the 400, you are looking at the effects of perspective in those shots NOT depth of field.
Yes - the tower is bigger and blurred part is bigger too - thus better blur in my eyes.
In the extreme smallness, the tower will be one pixel width -> perfectly "in focus" = the worst background blur possible, for me...
Opposite extreme: the tower fills whole background = one gray color around the subject = the most blurred background (little boring thus I do not call this "the best" though still good example of the biggest isolation).

You're confusing what is in the background vs. how much that background is out of focus.
It is not confusion of those characteristics, but sum of all that make final subject isolation, which OP was asking about. There is only one place (distance from camera) which is in the perfect focus, all other things at other distances are blurred, but if you use longer focused distance or bigger F number or smaller FL the blur is smaller ~ even invisible on the final picture...
Another example: shooting straight en face with 50/2.8 both eyes are sharp pretty the same, but shot with 300/2.8 = it is easy to say which eye was focused on.

56
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 04:22:14 PM »
Exactly.  Your eyes are being fooled. The blur is the same. That it doesn't look that way is an illusion. But...it's a good illusion.
I think that we need to define "background blur" now, because it does not look like the same COC at 200mm and 400mm.
And what about my extreme examples in the previous post? Do you still call it: "my eyes are fooled"?

57
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 03:28:23 PM »
No, look again, the actual blur of the tower is the same, BUT the tower is much bigger with the 400, you are looking at the effects of perspective in those shots NOT depth of field.
Yes - the tower is bigger and blurred part is bigger too - thus better blur in my eyes.
In the extreme smallness, the tower will be one pixel width -> perfectly "in focus" = the worst background blur possible, for me...
Opposite extreme: the tower fills whole background = one gray color around the subject = the most blurred background (little boring thus I do not call this "the best" though still good example of the biggest isolation).

58
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 03:10:40 PM »
---CUT---
 This means, as has been said, that 600 f4 has exactly the same dof as a 17mm @ f4 if the subject is the same size in both frames. The images look quite different, but that is because of perspective, this series of images might help. http://www.luminous-landscape.com/tutorials/dof2.shtml
---CUT---
The images of FL 200mm and 400mm in the link prove my point of view - blur of tower is much bigger at 400mm.
+ I did lots of shots within the 50mm-300mm range and I know there is no way to get any comparable background blur if it is used 50/2.8 and 200/2.8 for the shots with the same framing...

59
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 02:59:13 PM »
My guess would be the EF-800mm F/5.6
My too.
I use/d 85/1.4, 135/2, 200/2, 300/2.8 and the most blurred background I've got with longer FL.
FL does affect the isolation of the subject more than open [wide] aperture.
(Using the same framing of a human body / face.)

If the two of you are guessing based on the maximum physical size of the aperture, then the winner is actually the 600 f/4. The 400 f/2.8 and the 800 f/5.6 are tied for second.

800 / 5.6 = 142.857
600 / 4 = 150
400 / 2.8 = 142.857

If you're going off focal length, then the 600 with a 1.4x teleconverter would beat the 800 without one.

At the same time, there's really not any significant difference in actual aperture size between them, just a small fraction of a stop: stop the 600 down to f/4.5 (a third of a stop, one click of the wheel) and it's now got a 133mm physical aperture.

If you were trying to decide between the three, your decision should be made primarily on focal length needs and you shouldn't give any consideration to the physical aperture. Indeed, they might all actually be the same, what with rounding and all: 600 / 142.857 = 4.2, which is closer to f/4 than f/4.5.

Cheers,

b&
Hmm, than the winner should be Sigma 200-500/2.8.
I did not take into account TC because it also blur subject :-D
(I do not have the experience of a difference between magnification by crop of a sensor [narrower DOF] and  prolonged focus distance [wider DOF]. I have only crop bodies 1.5x and 1.3x.)

60
Lenses / Re: Focal Distance: furthest possible maintaining blurred BG
« on: November 25, 2012, 02:40:18 PM »
My guess would be the EF-800mm F/5.6
FL does affect the isolation of the subject more than open [wide] aperture.

Not quite.  Contrary to popular opinion, Depth of Field is not affected by focal length only the physical size of the aperture (when maintaining subject height).  To maintain subject height in the image the subject distance must be increased as you increase focal length (in other words, you have to step back when using a longer lens).  Now, greater subject distance increases depth of field but a longer lens with the same f-number (eg. f/2.8 ) has a physically larger aperture which decreases depth of field.  It turns out the the increase of DoF due to increases subject distance is almost exactly offset by the decrease in DoF due to the physically larger aperture with the result that focal length does not affect DoF.
I do not know math behind the scene, but you hardly find the real aperture size of any lens with selected F stop. Thus the real aperture size is not attribute I can use to choose lens to shoot with. I know subject isolation ~ DOF of my lenses and longer FL isolate the subject more than shorter; even if I need to step back to maintain the framing & prolong focus distance.

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