- #71
Oldhouse
- 31
- 4
So what is your point... you still only get about 3mm in focus on the bottom picture but about 10+mm in the top picture... (if it is legible or not is irrelevant).
I didn't beat around the bush.Oldhouse said:So what is your point...
How do you know that? The top image is too small to make out individual ticks or where they start and end. That information is literally not available in the sparse data. You are interpolating which ticks you conclude are in-focus and which are not.Oldhouse said:you still only get about 3mm in focus on the bottom picture
Looks like you are slowly catching on to what DOF means:DaveC426913 said:I didn't beat around the bush.
The recognizable elements in both pics (22,23, 10,11) are exactly the same. The only concete metric we have - the tape measure's measurements - show the DoF has not been altered.
How do you know that? The top image is too small to make out individual ticks. That information is literally not available in the data. You are interpolating which ticks you conclude are in-focus and which are not.
That's the same circular argument. "All 10 ticks are in-focus because - despite being too small for my eyes to distinguish into discrete pixels - I am sure that must be in focus way down there in fractions-of-a-pixel-land."
Yes it has. The blur size of every point in the image has been increased by several times its original size in the blown up image. The fact that you can still make out the tape measure is irrelevant.DaveC426913 said:The recognizable elements in both pics (22,23, 10,11) are exactly the same. The DoF has not been altered.
This is the same tautology. You've proven nothing.Oldhouse said:Looks like you are slowly catching on to what DOF means:
It is all about being able to distinguish "discrete" points... If the image is small, you can't therefore it is considered in focus. The more you enlarge the image, the more discrete points you can distinguish.
No it wouldn't.Oldhouse said:Just think about it this way: If you had infinite resolution, you could keep enlarging the picture indefinitely. You would notice that the DOF shrinks more and more.
Again: That infinitely thin plane is the focal plane in the camera. Not in the printer's ink cartridges.Oldhouse said:The larger the picture, the less DOF you have. After all, as you know, only points from a specific distance are in focus (infinitely thin plane).
Nor do I need to.Oldhouse said:BTW, you still haven't given any answer to the posted formula...