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New depth of field calculator app

torger

Active member
Still getting to grips with the tilt screen.
One can start softly with the tilt screen. If you have live view / ground glass and shoot wide angles the workflow is really simple:

1) estimate distance to the ground and set hinge distance to that
2) look at live view and see how tall the tallest feature in the scene is, say it covers 50% of the height, adjust the span until it covers that amount, and you get an f-stop. If the scene doesn't have much height at all (say a seascape or something) you can even skip this and just use the app as a hinge distance table and shoot at the ideal aperture directly.
3) set the tilt, focus on live view / ground glass at the middle of the tallest feature, set the f-stop and shoot.

You don't need to use the focus distance / incline setting there as you focus manually. If you have say an ALPA with a HPF ring but no live view it can be nice to calculate the focus distance too though.

Then you can add the remaining features to this workflow as needed. Setting a separate ground distance is useful for longer lenses where you'd want to put the hinge line a fair bit below ground level to avoid having to apply large amounts of tilt that makes the wedge span really narrow. In my Linhof system it becomes useful for say the 72mm and up (~50mm 135 equivalent)

Then there's the camera tilt button which is there to compensate if tilting the whole camera. I almost never use that myself as I prefer to have a level camera and shift instead, and I think most tilt-shift users will do that.

There's also a sharp/soft button here merged into one button for space reasons. The typical tradeoff would be to let tree tops be a bit blurrier if the scene is tight, that is choose a soft edge on the near/upper limit.

The measurement modes are used if you want to measure angles instead of looking at the span directly on live view. This is typically useful for a bit closer distances where angles become a bit larger. For small angles it's hard to measure accurately, and much easier to see/measure on live view. The "span" measurement is the most useful, while "incline" and "hinge" is there for completeness but I don't expect them to be as much used.

There are some issues around hinge parallax when measuring and looking at wedge span, which is discussed in the manual how you handle it. It's generally a smaller problem than one may think though.
 

k-hawinkler

Well-known member
A great feature would be if users could share camera and less data they bothered to type in.
And download the data already typed in by others, avoiding unnecessary duplication of effort. :thumbs:
Then it would become a community tool, befitting the age of the Internet.
 

dchew

Well-known member
My first reactions:
- Wonderful. I finally have an app that calculates DOF in a way that I trust and makes sense! The Max setting is brilliant.

- The hyperfocal info always on the bottom is a very nice touch

- I think I understand what you are saying about the workflow using span and live view, but what about us poor souls with an IQ1XX who don't like fussing with LV? It might be good to have an area you could enter an "object distance" and the app would report back the height of the wedge at that distance. The Disto has the capability to read out height and distance in one reading, so it would be relatively easy to see if the tree fits in the wedge...

Very nice implementation! I have to play around more with the Tilt area to get more familiar with its capabilities but it seems well thought out. Many thanks for the effort.

Dave
 

torger

Active member
Thanks for the kind words. About the wedge height, do you really need it with the Disto, or could you just get away with the wedge span in degrees? That is you measure the span in degrees over that tree from the camera position and then you see that it fits? To get a correct incline and associated focus distance you need to take the hinge line parallax into account, meaning that if the hinge line is 2 meters below where you hold your instrument (you could measure directly with the phone too, but it's a bit awkward to aim compared to a disto of course) you need to aim 2 meters above the target for the upper and lower angles.

I think the idea of wedge height is nice, but as the screen is out of button space I need to make sure that it's really needed :)

My first reactions:
- Wonderful. I finally have an app that calculates DOF in a way that I trust and makes sense! The Max setting is brilliant.

- The hyperfocal info always on the bottom is a very nice touch

- I think I understand what you are saying about the workflow using span and live view, but what about us poor souls with an IQ1XX who don't like fussing with LV? It might be good to have an area you could enter an "object distance" and the app would report back the height of the wedge at that distance. The Disto has the capability to read out height and distance in one reading, so it would be relatively easy to see if the tree fits in the wedge...

Very nice implementation! I have to play around more with the Tilt area to get more familiar with its capabilities but it seems well thought out. Many thanks for the effort.

Dave
 

AreBee

Member
Anders,

Some additional observations:

1. The Show focus stack toggle works on my iPhone but not on my iPad mini - on the latter, the Stack button is always visible on the main screen.

2. On the Tilt screen, the incline column values can be scrolled even when the column has been locked. This is true for my iPhone and iPad mini.

3. Is it by design that the App does not auto-rotate between landscape and portrait aspect?

4. "User interfaces today try to get rid of as many ok and cancel buttons as possible to reduce the number of clicks/taps required..."

At present a user has to press the 'back' button in order to return to the main screen - four times in the case of creating a new lens entry. A 'close' button for nested levels greater than one would require fewer button presses. Just sayin'. :lecture:
 

dchew

Well-known member
Good point about using degrees on the disto. That (or the phone directly) would probably work fine. I need some field time!

I figured you would have real estate issues adding an object height. Probably the way to do it would be a choice between incline or object height. Not easy!

Dave
 
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dchew

Well-known member
Anders,

Some additional observations:

1. The Show focus stack toggle works on my iPhone but not on my iPad mini - on the latter, the Stack button is always visible on the main screen.

2. On the Tilt screen, the incline column values can be scrolled even when the column has been locked. This is true for my iPhone and iPad mini.
Hey Rob,
I have a mini also, and the stack button appears. Might you have to option turned off in settings?

The lock at the bottom of Incline fixes the wedge point either at the top (near) middle (PoF) or bottom (far) as you make other changes. It doesn't lock the incline column. I think that is by design.

Sorry to respond for Anders but my guess is he is getting many questions right now!

Dave
 

AreBee

Member
Dave,

I have a mini also, and the stack button appears.
Toggle it off in the settings. Is the button still visible?

The lock at the bottom of Incline fixes the wedge point either at the top (near) middle (PoF) or bottom (far) as you make other changes. It doesn't lock the incline column. I think that is by design.
Ah, okay, I didn't appreciate that. Thanks.
 

f8orbust

Active member
Same issue here on an iPad Air running iOS 9.3.1 / Firmware 6.02.00

i.e. Settings > Show focus stack button

has no effect, the button is always displayed.

Works fine on the iPhone.
 

torger

Active member
Same issue here on an iPad Air running iOS 9.3.1 / Firmware 6.02.00

i.e. Settings > Show focus stack button

has no effect, the button is always displayed.

Works fine on the iPhone.
Issue confirmed, that's a bug. I'll fix it in the next update. Thanks for reporting.
 

torger

Active member
1) that's a bug, I'll fix it in the next update, thanks for reporting.

2) This is by design. The reason is that the incline is disconnected from the other columns so locking it would make no difference so it would be a meaningless function. Instead I made a special lock button which is always on the near/far/PoF lock you can cycle which causes the incline to auto-adapt to keep near/far still. Overall the locks are less needed in the tilt screen, the hinge will only move if you change span *a lot*, in the typical workflow you can set all your tilt settings without locking. I still chose to keep locks to make the tilt screen similar to the main screen and I also think that it's a good learning tool to lock one parameter and see how the others change, for example if f-stop is locked span can still be changed, but not without changing hinge distance etc.

3) Yes that is by design. For smartphones I think it makes sense, but for the tablets I probably should make it turnable at some point. The tablet support was added pretty late, hence the bug in 1). In the field I'm thinking most will be using a smartphone so I don't see it as a high priority feature at this point. However I noted that when adding tablet support I found myself playing around with the app more on my tablet than on my phone, so for playing around and learning the tool I guess tablet use may become pretty common. It is some work to implement the feature as the current dynamic layout requires that the screen is higher than wide to make good layout decisions, and that would have to be generalized.

4) Yes that's a good point. Most my design effort has been put into the use of the Dof/tilt screens and which configurations you can set, while actually making the setting of configuration as effective as possible has not been a key priority. In that case I've just used the standard design patterns in the framework of how screens are interconnected and then it ended up that way. Breaking a framework design pattern is usually quite a big effort as the framework makes it easy to make things work the way the framework designers intended and as a side effect (intentional or not) hard to make it in any other way. As configuration is something you do seldom I won't put too much effort into making it as smooth as possible. As I see it the most important thing is that you can configure certain settings, then it's secondary that it can be made as efficient as possible.

On the dof/tilt screens however it's a top priority that you can do things efficiently as that is what you are supposed to see of the app 99% of the time.

Anders,

Some additional observations:

1. The Show focus stack toggle works on my iPhone but not on my iPad mini - on the latter, the Stack button is always visible on the main screen.

2. On the Tilt screen, the incline column values can be scrolled even when the column has been locked. This is true for my iPhone and iPad mini.

3. Is it by design that the App does not auto-rotate between landscape and portrait aspect?

4. "User interfaces today try to get rid of as many ok and cancel buttons as possible to reduce the number of clicks/taps required..."

At present a user has to press the 'back' button in order to return to the main screen - four times in the case of creating a new lens entry. A 'close' button for nested levels greater than one would require fewer button presses. Just sayin'. :lecture:
 
Thanks, very nice app (especially for the CoC flexibility). Just bought it.

The Leica S has the DoF calculator integrated in the camera. Their CoC-Formula (which is not adjustable) apparently comes quite near to the one recommended by you. Funny thing is that the DoF tables, provided by Leica in their technical spec sheets for every S lens, are quite different. Apparently even Leica has not decided yet which formula they prefer :)
 
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dchew

Well-known member
Anders,

Been thinking about the Tilt Span/Incline options:
mm on sensor
mm on LV
% sensor H
% sensor W

Those last two might be useful, except as you switch orientation from portrait to landscape you would have to go into settings and change it every time. It would be nice to add the ability to quickly swap from % sensor H to % Sensor W. Perhaps if a 3-second press of the "span" button cycled through %H / %W when someone has chosen one of the two "%" options. Another possibility is a 3-second press that brings up a different pop-up to select one of the four options.

Dave
 

torger

Active member
Thanks for the idea. I'll consider that for a future update! As I'm a ground glass user I've been used to working with the mm scale and then digital back orientation doesn't matter, but indeed with %w/%h swapping easily would certainly be useful.

I've just submitted a version 1.0.3 with some minor bug fixes and the ability to import/export configuration via the clipboard, plus rearranging the scroller order for those that prefer a different order. I didn't implement a "cloud service" for configuration sharing/upload, it's quite much work, but with the import/export via the clipboard you can copy configuration between devices and even manually edit the configuration on a computer if you're daring.

The update is already out for Android as Google Play has automated reviews for app updates, but Apple's App Store have manual reviews also for them meaning that it can take everything from a few hours to a few days until the update appears in the Store.

Anders,

Been thinking about the Tilt Span/Incline options:
mm on sensor
mm on LV
% sensor H
% sensor W

Those last two might be useful, except as you switch orientation from portrait to landscape you would have to go into settings and change it every time. It would be nice to add the ability to quickly swap from % sensor H to % Sensor W. Perhaps if a 3-second press of the "span" button cycled through %H / %W when someone has chosen one of the two "%" options. Another possibility is a 3-second press that brings up a different pop-up to select one of the four options.

Dave
 

torger

Active member
By the way, it would be most helpful if some of you could rate the app in the app store. The reason I ask is that the stores uses the in-store ratings as one important factor to make the app visible or not when searching/browsing, and an app with no ratings stays relatively invisible. Actually, it seems like in terms of visibility it's better to have a bunch of bad ratings than none at all :)
 

MGrayson

Subscriber and Workshop Member
Anders,

Nice app! But is the Leica S sensor size too weird to have in the list? 30x45mm, 6µ pixels. Yes, it wasn't hard to add as custom. ;)

Do you incorporate diffraction? I'm usually less bothered by it than other calculators suggest, so I'm just as happy if it is ignored.

--Matt
 

dchew

Well-known member
The update is already out for Android as Google Play has automated reviews for app updates, but Apple's App Store have manual reviews also for them meaning that it can take everything from a few hours to a few days until the update appears in the Store.
FYI, I got the update this afternoon from Apple App store.

Dave
 

torger

Active member
Anders,

Nice app! But is the Leica S sensor size too weird to have in the list? 30x45mm, 6µ pixels. Yes, it wasn't hard to add as custom. ;)

Do you incorporate diffraction? I'm usually less bothered by it than other calculators suggest, so I'm just as happy if it is ignored.

--Matt
Ok, I'll add the 30x45mm size to the next update :)

As there's many different views on how circle of confusion should be set, for example to incorporate diffraction or not, I've left this up to the user to configure. You can choose to have a traditional CoC size only related to the sensor diagonal, or one related to pixel size, or indeed one related to airy disk (diffraction), or my personal favourite a max(airy,pixel). All with scale factors. This is explained in more detail in this section of the manual:
http://www.lumariver.com/lrdof-manual/#toc18

The default setting is setting CoC = airy disk diameter, which has the advantage that it's unrelated to sensor size and pixel pitch so it doesn't matter what camera properties you have. However if you do know your sensor size and pixel pitch you may gain from using a more advanced setting, as discussed in the manual.
 
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