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Wha'ts all this crop sensor DoF Stuff?
May 2, 2024 00:30:29 #
Ysarex
Loc: St. Louis
Longshadow wrote:
If I find the troll I'll let you know.
You have to be able to recognize the troll to find it. Trolls disguise themselves.
May 2, 2024 05:00:16 #
Ysarex wrote:
In my most recent example (grave markers) I was focused on something less than 20 feet away. You're off somewhere in clueless land.
In my most recent example distances for DOF were in the 10, 20, -- 40 feet range. And you're still wrong.
In my most recent example distances for DOF were in the 10, 20, -- 40 feet range. And you're still wrong.
You must have let the camera pick the focus point, otherwise you would have remembered.
Your 20MP camera's crop factor is about 2.7. Your HD at f/5.6 is about 16 feet and the near limit about 8 feet.
To get the same framing and DOF with a full frame camera would have needed a 50mm lens at f/16. This is just beyond the lens's diffraction limit but with a 2k image like you post nobody would not have seen it. f/8 and a shallower DOF would have been sharper for anything other than deep landscape if you post the full image.
Do you only take snapshots of landscape and flowers? Anyone can do that. Where are your non-landscape photographs?
May 2, 2024 05:03:31 #
Ysarex wrote:
It is pretty simple. You waste DOF if you focus on what's closest to you.
What if what's closest to you is the actual subject?
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May 2, 2024 05:25:40 #
Ysarex wrote:
I'd love this thread to end right now. Soon as the troll stops chewing on my ankle I'm gone.
You have not really added much value here. Your departure from this thread would be a welcome relief to us all.
May 2, 2024 07:03:36 #
Ysarex wrote:
You have to be able to recognize the troll to find it. Trolls disguise themselves.
They certainly do!
May 2, 2024 07:17:43 #
User ID wrote:
Like most Hawgsters, you dont even know what a troll is, or what trolling is.
The pejorative is tossed out in frustration. A mirror would be a handy tool.
May 2, 2024 07:20:08 #
Ysarex
Loc: St. Louis
selmslie wrote:
You must have let the camera pick the focus point, otherwise you would have remembered.
I did remember and I noted where I set the focus point. And you're still wrong.
selmslie wrote:
And you got that wrong too. Hyperfocal distance was 32 feet.Your 20MP camera's crop factor is about 2.7. Your HD at f/5.6 is about 16 feet and the near limit about 8 feet.
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May 2, 2024 07:25:32 #
Ysarex
Loc: St. Louis
selmslie wrote:
What if what's closest to you is the actual subject?
Well you could finish quoting what I said and have the answer. Do you need help with reading? And you're still wrong. Did you notice that Frankraney also recognizes that you're wrong?
May 2, 2024 07:38:46 #
Ysarex wrote:
And you got that wrong too. Hyperfocal distance was 32 feet.
Not for a 1” sensor, 18mm at f/5.6. You need to learn how to use the DOF calculator I suggested.
May 2, 2024 08:03:12 #
Ysarex
Loc: St. Louis
selmslie wrote:
Not for a 1” sensor, 18mm at f/5.6. You need to learn how to use the DOF calculator I suggested.
Apparently we have two conflicting DOF calculators. It happens. So you're not wrong about HD and neither am I. Answer could well be in the middle -- not worth chasing. DOFMaster reports the value it's using for CoC Cambridge in Colour doesn't.
But you're still wrong with your original statement that understanding how DOF distributes around the focus plane isn't really helpful. Frankraney knows it's helpful and just a few posts back said as much. In fact Frank repeated an old industry rule-of-thumb (1/3 rule) that's been around since even before you that demonstrates photographers have long since recognized that understanding how DOF distributes around the focus point can be helpful. The whole photo industry since before you were born has known you're wrong.
May 2, 2024 08:12:54 #
selmslie wrote:
The pejorative is tossed out in frustration. A mirror would be a handy tool.
May 2, 2024 08:32:51 #
Ysarex wrote:
Apparently we have two conflicting DOF calculators... (show quote)
DOFMaster has the wrong COC.
The crop factor is 2.72. Starting from the full frame COC of 0.03mm you end up with .03/2.72=.011mm, not .006mm.
Incidentally, the iPhone 15 Pro at 48mm equivalent at a crop factor of 7 has a hyperfocal distance of 6.35 meters, almost the same as your Canon. You could have captured the same image as with your Canon but at 12MP. Since you downsized it to about 2.65MP for posting, either one would have produced about the same result.
From Cambridge in Colour
May 2, 2024 09:22:33 #
selmslie wrote:
Incidentally, the iPhone 15 Pro at 48mm equivalent at a crop factor of 7 has a hyperfocal distance of 6.35 meters, almost the same as your Canon. You could have captured the same image as with your Canon but at 12MP. Since you downsized it to about 2.65MP for posting, either one would have produced about the same result.
Here is the equivalence between an iPhone and a full frame (24x36mm) camera.
I don't compare the iPhone directly to other formats but I have a way to compare full frame to a series of formats from APS-C (1.5) up to 8x10 including a couple of medium format digital sizes.
I also wrote a DOF calculator where I can vary the calculation of COC based on several popular assumptions.
For more on this topic, see Smartphone Depth of Field (DoF) With a Full Frame Camera
Sample results for one of the iPhone 15 cameras
And here is the download for the spreadsheet, updated for the iPhone 15
Attached file:
(Download)
May 2, 2024 10:16:42 #
Ysarex wrote:
Apparently we have two conflicting DOF calculators. It happens. So you're not wrong about HD and neither am I. Answer could well be in the middle -- not worth chasing. DOFMaster reports the value it's using for CoC Cambridge in Colour doesn't.
If you have been relying on DOFMaster, that would explain your confusion. I found several errors in their logic so I don’t trust them although the can probably do alright for full frame and APS-C.
The spreadsheet I just uploaded shows five different versions of COC based on visual acuity. For simplicity I just use image diagonal/1500.
May 2, 2024 11:26:45 #
Ysarex
Loc: St. Louis
selmslie wrote:
DOFMaster has the wrong COC.
Fine. No big deal. My favorite DOF calculator is PhotoPils but DOFMaster is the fastest and easiest to use.
Calculator errors don't alter the visible results in the photos. The photo of the grave markers remains a good example of applying the useful understanding of DOF distribution to effectively place DOF in a photo.
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