Edit: You obviously can see the front focus. This is due to the me being unable to get the "£%"$^£%^£$% front plate off and adjust the front element.
The focusing ring reaches the infinity at around 5-6m, and if I have to continue sanding the shim instead, it will be thin as a leaf....
helimat wrote:
That statement is incorrect I am afraid; The DOF with a lens would be regardless of the sensor format given the distance, focal length and aperture stay the same. So a wide open Rokkor @ 2 meters distance would have the same DOF on a full frame or a crop sensor, and even m4/3's for that matter.
if you blow the images up to the same print size however, the apparent dof will be different. dof is actually highly dependent on the size and distance you view an image from. things that look like they are within the dof at normal viewing size can look like they are oof when viewed at 100%. this is (one of the reasons) why many people complain that the distance scales on their old lenses don't work on digital - they are viewing the images at 100% on their monitor where they can see that at a hyperfocal distance everything is not equally in focus (if they looked at an 8x10 print instead they wouldn't notice this).
The physical DOF would still be the same dimension. What happens behind the lens, or on a print for that matter, may have some effect on how it is viewed, but to say the DOF itself would change with a change of sensor format is retarded.
I am not trying to make a statement or accuse anyone..
It's just impossible for me to get this massive DOF while having lens WO, so I referred to DOF master in order to get ideas...
helimat wrote:
The physical DOF would still be the same dimension. What happens behind the lens, or on a print for that matter, may have some effect on how it is viewed, but to say the DOF itself would change with a change of sensor format is retarded.
if you think talking about how a picture actually looks is retarded, you're certainly entitled to that opinion. dof field isn't a real thing though, it is an arbitrary amount of blur that is viewed as acceptable. the actual focus plane is always infinitely thin. i certainly agree that DOF master is useless though.
sebboh wrote:
if you think talking about how a picture actually looks is retarded, you're certainly entitled to that opinion. dof field isn't a real thing though, it is an arbitrary amount of blur that is viewed as acceptable. the actual focus plane is always infinitely thin. i certainly agree that DOF master is useless though.
No, I am saying that 'DOF Master' is retarded, because the physical DOF does not change with sensor size. The sensor does not effect how a lens bends light. Of course the final image may look different with different sensors, but that is a pretty obvious statement that has no bearing on the original statement that I took issue with.
I am not trying to flame up the forum or anything, and I have a lot of respect for the work you do, sebboh, so please don't take offense. I think we are just looking at it two different ways.
Krosavcheg wrote:
So the bottom line is that all lenses produce exactly same results on all the sensors?
(apart from obvious sensor qualities, of course)
No... Just that a single lens, say a Rokkor 58/1.2, will have the same DOF dimension regardless of sensor size as long as the aperture and distance remain constant.
I think sebboh is trying to say the output size will have a perceived difference in DOF too, and I think he is right there. But that has nothing to do with sensor size...
helimat wrote:
No... Just that a single lens, say a Rokkor 58/1.2, will have the same DOF dimension regardless of sensor size as long as the aperture and distance remain constant.
I think sebboh is trying to say the output size will have a perceived difference in DOF too, and I think he is right there. But that has nothing to do with sensor size...
Pardon my wording...that's pretty much what I had in mind. As in this case with Rokkor - regardless of the sensor the DOF remains exactly the same. And of course same would attribute to say Rokkor 135/3.5 and etc, etc...
Dang...in some cases I believed the calc and actually stopped the lens down, when I could have shot WO...especially if 58/1.2 DOF is that wide....
Back to your original question... I would have to think that the DOF would be less than 8cm @ 2m distance wide open, so I think you are right, DOF Master is wrong.
Yepp, it really is the case. I just checked few threads at other boards and it seems that DOF Master does calculate incorrectly.
Though, you can see much deeper DOF than 8cm in the Denoir's shot...or at least I see, anyway......
helimat wrote:
No, I am saying that 'DOF Master' is retarded, because the physical DOF does not change with sensor size. The sensor does not effect how a lens bends light. Of course the final image may look different with different sensors, but that is a pretty obvious statement that has no bearing on the original statement that I took issue with.
I am not trying to flame up the forum or anything, and I have a lot of respect for the work you do, sebboh, so please don't take offense. I think we are just looking at it two different ways.
no offense taken, and DOF master is clearly not particularly useful. i know your saying that changing the sensor has no effect on the image a lens projects which is definitely true. i'm just trying to say even though the projected image is identical on crop vs FF, when you crop that image and blow it up to the size of the uncropped image you will change the perceived dof. this is an important thing to be aware of particularly with alt glass the has a dof scale on it. having said a'll that, i have seen so much difference in apparent dof (and steepness of transition) at the same focal length and aperture with different lenses that i think one just needs to play around with a lens to get a feeling for it.
..or buy DOF refill..