Estimating Hyperfocal Distance the Easy Way

[xpatUSA]

The hyperfocal focal distance is a useful thing to know, but figuring it out the conventional way (tables, calculators, CoC, etc.) is not especially convenient in the field for me. It would be nice to do it mentally, especially if you normally shoot at particular focal length, like f/8 with my fixed 24mm compact camera.

There is another way involving just the actual aperture diameter and an angle (the vertex angle of a cone of confusion).

For me, normally shooting at f/8 with that camera, I know that the aperture diameter is 24/8= 3mm.

But, what about that angle? Photographers generally avoid angles but they can be useful. In this case, it is possible to avoid having to know the CoC for each and every format of sensor that you own.

Instead pick an angle relative to human visual acuity, which is said to be on average 1 minute of arc (Snellen's 20/20 vision). And remember that angle, but remember it in radian measure ... 0.291 milli-radians (mrad). Now pick an angle greater than that to account for your viewing habits. In my case, I view on a monitor screen with 0.265mm pixel pitch about half a meter away (about 0.52mrad). Conveniently, I'll pick 0.5mrad for that.

The hyperfocal estimate = aperture diameter in mm / your angle in mrad.

http://www.dicklyon.com/tech/Photogr...Field-Lyon.pdf

Easy to figure (especially with my carefully-chosen numbers):

Aperture diameter = focal length / f-number = 24mm / 8 = 3mm.

3mm/0.5mrad = your hyperfocal distance = 6 meters = ~20 feet.

Not looking for education on DOF, CoC, etc., just passing on a personal tip.

[Manfred M]

Of course these days with apps on our cell phones, life can be quite easy. I use a pay app called PhotoPills for all kinds of photo information, including hyperfocal distance charts. I suspect there are all kinds of free apps out there too.

[xpatUSA]

Of course these days with apps on our cell phones, life can be quite easy. I use a pay app called PhotoPills for all kinds of photo information, including hyperfocal distance charts. I suspect there are all kinds of free apps out there too.

Of course.

Unfortunately my cell phone has to be on charge all the time, so I don't carry it much - only for trips to town. So I wander around the property with a lightmeter, a camera and what's left of my brain. But, I suppose a pocket calculator would make the Method easier, eliminating the need for mental arithmetic with difficult numbers like 5.6 ...

[Manfred M]

Of course.

Unfortunately my cell phone has to be on charge all the time, so I don't carry it much - only for trips to town.

Nothing a new battery wouldn't fix? I just replaced my 2012 Samsung Galaxy S3. The battery was dying (again) but the phone was so old that it had trouble running the updated software..

[xpatUSA]

Nothing a new battery wouldn't fix? I just replaced my 2012 Samsung Galaxy S3. The battery was dying (again) but the phone was so old that it had trouble running the updated software..

Thanks Manfred, a not-unexpected response. I bought five new Samsung S II Skyrocket OEM batteries on eBay last year but it seems either their age was against them (only two left); or my Samsung draws more current than it used to and I really can't be bothered to mess with it. So, on the charger it stays ... been looking occasionally for a phone that just dials numbers and lasts a whole week on one charge ... haven't found one yet. Anybody?

Meanwhile, OT but my pocket calculator is solar-powered so that would be a Good Thing.

[xpatUSA]

... been looking occasionally for a phone that just dials numbers and lasts a whole week on one charge ... haven't found one yet. Anybody?

Well, what d'ya know!!

https://smallbiztrends.com/2015/05/l...kes-calls.html

20 days between charges and hopefully crowd-funded by now ...

[joebranko]

What a revolutionary idea! A phone that makes calls!😀

[xpatUSA]

What a revolutionary idea! A phone that makes calls!

si viva la revolucion ... I've reserved one from the next production run!

[loosecanon]

there are lots of simple phones with basic operations, including camera, for not much money that last a week or more.
Leaving any lithium battery on charge all the time ruins the battery. A common reason laptop batteries fail. Lithium batteries need to go through discharge cycle occasionally, and best stored no more than 50% charged.

On topic, surely hyperfocal distance is dependebt on print size and viewing distance, its just a rough guide, and now we need to allow more back focus, making the distant objects/mountains etc properly sharp, rather than at the limit of sharpness.

[xpatUSA]

On topic, surely hyperfocal distance is dependent on print size and viewing distance, its just a rough guide, and now we need to allow more back focus, making the distant objects/mountains etc properly sharp, rather than at the limit of sharpness.

From the OP: "Not looking for education on DOF, CoC, etc." and I don't print.

[george013]

Thanks Manfred, a not-unexpected response. I bought five new Samsung S II Skyrocket OEM batteries on eBay last year but it seems either their age was against them (only two left); or my Samsung draws more current than it used to and I really can't be bothered to mess with it. So, on the charger it stays ... been looking occasionally for a phone that just dials numbers and lasts a whole week on one charge ... haven't found one yet. Anybody?

Meanwhile, OT but my pocket calculator is solar-powered so that would be a Good Thing.

Start the phone in 'safe modus' and see what happens. Maybe your old batterij is still working well. Mine is doing now 4 till 5 days. Samsung s4.


George

[xpatUSA]

Start the phone in 'safe modus' and see what happens.

Thank you for the suggestion, George. How is the phone started in safe mode exactly? What key pushes?

Maybe your old batterij is still working well. Mine is doing now 4 till 5 days. Samsung s4.


George

[george013]

Thank you for the suggestion, George. How is the phone started in safe mode exactly? What key pushes?

You have to google that for your phone. Or rtfm😊
When it's running in the save mode it's running as new, no apps loaded. In my case it was google earth that kept running in the background. Removing that solved my problem.

George

[xpatUSA]

You have to google that for your phone. Or rtfm
When it's running in the save mode it's running as new, no apps loaded.

George

Thanks again. Unfortunately in this household "fm" means "first mislaid".

Meanwhile, searching has not yet shown up the correct arcane sequence for my old Galaxy S2 Skyrocket. Samsung seems about as consistent as Sigma, so I'll just keep looking.

[george013]

Thanks again. Unfortunately in this household "fm" means "first mislaid".

Meanwhile, searching has not yet shown up the correct arcane sequence for my old Galaxy S2 Skyrocket. Samsung seems about as consistent as Sigma, so I'll just keep looking.

I wouldn't have thought you had trouble with Google. Searcy 'Samsung s2 safe mode'.
Turn off phone. Start and when it'starts keep then the minus volume button pressed. You will see a sign it's in the safe mode. See what your batterij does after a day.

George

[xpatUSA]

I wouldn't have thought you had trouble with Google.

LOL

Searcy 'Samsung s2 safe mode'.
Turn off phone. Start and when it'starts keep then the minus volume button pressed. You will see a sign it's in the safe mode. See what your batterij does after a day.

George

I had already found and followed the instructions for the Galaxy S2. They did not work. Mine is a Galaxy SII Skyrocket, not even the same battery as the S2 (already made that mistake, thanks Samsung).

Thanks again for your help. I'll take it from here so as not to hijack this thread.

[edit] I found a PDF manual on-line. As I suspected, the Galaxy SII Skyrocket instructions for Safe Mode are completely different from anything I've read to date - including yours.[/edit]

[george013]

LOL



I had already found and followed the instructions for the Galaxy S2. They did not work. Mine is a Galaxy SII Skyrocket, not even the same battery as the S2 (already made that mistake, thanks Samsung).

Thanks again for your help. I'll take it from here so as not to hijack this thread.

[edit] I found a PDF manual on-line. As I suspected, the Galaxy SII Skyrocket instructions for Safe Mode are completely different from anything I've read to date - including yours.[/edit]

Well, you know now in what direction you've to look.
https://www.hardreset.info/devices/s...recovery-mode/

Whatever you do, Back-up your data.

It is the same as with pc's. The pc doesn't get slow when the os is getting old. It just has to many visitors using its resources.

George