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New depth of field calculator app

torger

Active member
With my Linhof Techno I've been using my own custom tables with hyperfocal, hinge distances and wedge spans for all my lenses and various apertures, and I still use them. However nowadays with always a smartphone in the pocket I've thought about having an app at least as a complement for some time. I've used a simple viewfinder app for quite some time to help in composition before I mount the camera, but I haven't really found a DoF app that I've liked more than simply using my printed tables.

I've had some ideas on how to make an app in a better way, at least as I see it :). I started to work with it more than a year ago but it was put on ice due to other efforts, but finally I've been able to finalize it and release "Lumariver Depth of Field Calculator", available for both Android and iOS.

I've made a lot of free software in my days, but this one is not one of them so I guess you could call this a commercial, but I honestly do think it has a major relevance for tech users (and well any high resolution camera for landscape and architecture) and of course I designed it to use it myself. And if Phase One dealers can post, I hope I can :).

It's probably a little bit too advanced for Average Joe, like most stuff I do it's niche. As that it's a bit more expensive too ($9), but I don't think anyone has put this much effort into a DoF calculator before...

Here's direct link to the store fronts:
iOS:
https://itunes.apple.com/se/app/lumariver-depth-field-calculator/id1102190226?l=en&mt=8

Android:
https://play.google.com/store/apps/details?id=com.xarepo.lumariverdof

...but the home page entry is more fun, where you find a demo video, instruction video and a user manual:
Lumariver Depth of Field Calculator homepage

What I often lack in other DoF apps is configurability, for example concerning circle of confusion, everyone seems to have their own preference of what it should be. I also prefer to have my own lenses setup rather than a drop-down to enter my focal length. I also think many apps have been lacking in efficient GUI layout, and I've addressed all those aspects.

When it comes to tilt calculators there haven't been much to choose from at all, there are one or two, but I haven't found one that even shows wedge span in actual height which I think is so much more useful for live view and ground glass users than just a degree value.

Oh, there's a focus-stacking mode there too to make the app "complete" as focus-stacking has become increasingly popular even in landscape applications. How useful that mode is will depend on what type of gear you have though, and like the tilt function it can be disabled if you don't need it so it won't clutter the user interface unnecessarily. I'm not a big fan of focus stacking myself but I've really tried to get into it and make it as useful as it could be.

I've attached a couple of screenshots. The design is oriented around a set of inter-connected scrollers and locks, and an animated diagram on top. We like metric units here in Sweden as seen in the screenshot but you can configure it to decimal feet too. I hope someone more than myself likes it :), I've calculated that I would need to sell about 5000 copies to make break-even compared to the ordinary paid software development work I do, but if I manage to get 50 out of this niche app I'm happy, which I guess is about 50% of the total tech cam population these days so it's still a tough goal ;).
 

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dougpeterson

Workshop Member
Looks like a great app for those that already know what they are doing and just want a fast and accurate way to do the appropriate math.

Kudos!
 

Jamgolf

Member
Just purchased it myself.
Will provide feedback after a few days of use.
Thanks for putting in the effort.
Cheers!
 

Jamgolf

Member
Quick question:
May be I am not noticing something obvious but is there a way to set values in feet and not meters?
 

torger

Active member
Yes it's there under the settings, thanks Dave for replying while I was sleeping :). Currently I only support meters and decimal feet. I'm not sure if that's enough or if there's some other unit I should support too. If you find something obvious missing please let me know so I can add in a future release.

As seen on the screenshots the GUI is quite compact, it's designed to fit on an iPhone 5 / SE (screenshot shows a Nexus 5). On larger phones (and tablets) the interface adapts and the diagram gets larger but the buttons and information stays the same.
 

AreBee

Member
Anders,

If you find something obvious missing please let me know so I can add in a future release.
Perhaps not missing, but you may wish to consider the following suggestions for improvement:

1. I consider it a mistake to include the lenses section in the camera system section. Many lenses can be used on multiple bodies, especially these days with mirrorless cameras. Therefore, a lens section should be independent of a body section. More importantly, at present if a new body (as part of a camera system) is created, new lenses for it must also be created, even if lenses defined for another body (camera system) can be mounted to it.

For example, if you create a Nikon D800 camera system and accompanying lenses, then create a Nikon D100 camera system, on the main screen you can't select lenses defined for the D800, even though in reality they can be mounted to a D100.

2. When using the app for non-tilt (I have not yet considered tilt :toocool:) depth of field, my order of operation would be to scroll (or, more likely fix, in order to limit diffraction) f-stop, then scroll values of focus and consider the near and far column values until I was satisfied with the depth of field returned.

At present the focus column is on the far right, whereas it seems logical to me for the column order to be: f-stop, focus, near, far. From an ergonomic point of view this would make it easier to adjust the f-stop and focus columns with one finger (in my case my left hand thumb). It would also mean that my finger does not obscure the near and far column values when making adjustments.

3. After selecting a camera system or lens in the main screen header there is no way for the user to cancel. They can simply reselect the camera or lens already selected, but in principle should there be an ok button, as per the set focal length screen?

4. Given that the camera system shortname is displayed in the main screen header, what is the purpose of the (non-shortened) camera system name? The person that created the custom camera system will have no difficulty recognising the former...because they created it. Is the latter superfluous?

Apart from that it's pretty good. :grin:
 

k-hawinkler

Well-known member
I was expecting to downselect from a menu my cameras and lenses.
Is there a version running on a Mac computer?
 

torger

Active member
Thanks for the feedback;

1. Ok, I consider it to be a mistake :). I see your point. However you can always enter the lens again on the other system. It's a bit messy to reorder the configuration structure for upgrades, but I guess a middle way would be to be able to when you add a new lens to pick from a list of lenses you've already entered for any system so it's easy to duplicate them. In my case I wouldn't want all my lenses to be available on all systems as I don't use any Digitars on my Canon and no Canons on my Linhof. The idea is to present only the lenses you have at hand when in the main screens working to keep it clean.

2. I actually have considered that order. The reason the order is the way it is is a tradeoff between several design goals, one being to match order with the tilt screen where the focus distance is the rightmost column. It's not possible to make an order that suits everyone, however it would be easy to make the column order configurable so it would suit different workflows and left-handed and right-handed people. Good idea, I will definitely consider that.

3. This is the part of the new tradition of user interface design, it's actually not me that has chosen that way, it's the framework. User interfaces today try to get rid of as many ok and cancel buttons as possible to reduce the number of clicks/taps required, and one result of that is that a selection dropbox don't have any ok button if not needed. The scroller for focal length needs it as the app doesn't know if the user is ready picking. On Android phones there's the hardware back button, and on tablets the modal doesn't cover the full screen so you push on the side. While I do see you have a point, I'm probably not changing this part as it's the way list selection works these days.

4. The non-shortened name is used in the camera system selection list. It's a matter of preference if one cares to make a beautiful long name or not. In my case my shortname is "Techno" and the longname is "Linhof Techno / H4D-50 Hasselblad", and "5Dmk2" and "Canon EOS 5D Mark II". The same is for lenses, I've entered "Schneider-Kreuznach Apo-Digitar XL 47mm/5.6" for longname and "SK47XL" for shortname. It doesn't fulfill any function as such to have the full name, I just think it looks nice when selecting lens / camera.

Anders,



Perhaps not missing, but you may wish to consider the following suggestions for improvement:

1. I consider it a mistake to include the lenses section in the camera system section. Many lenses can be used on multiple bodies, especially these days with mirrorless cameras. Therefore, a lens section should be independent of a body section. More importantly, at present if a new body (as part of a camera system) is created, new lenses for it must also be created, even if lenses defined for another body (camera system) can be mounted to it.

For example, if you create a Nikon D800 camera system and accompanying lenses, then create a Nikon D100 camera system, on the main screen you can't select lenses defined for the D800, even though in reality they can be mounted to a D100.

2. When using the app for non-tilt (I have not yet considered tilt :toocool:) depth of field, my order of operation would be to scroll (or, more likely fix, in order to limit diffraction) f-stop, then scroll values of focus and consider the near and far column values until I was satisfied with the depth of field returned.

At present the focus column is on the far right, whereas it seems logical to me for the column order to be: f-stop, focus, near, far. From an ergonomic point of view this would make it easier to adjust the f-stop and focus columns with one finger (in my case my left hand thumb). It would also mean that my finger does not obscure the near and far column values when making adjustments.

3. After selecting a camera system or lens in the main screen header there is no way for the user to cancel. They can simply reselect the camera or lens already selected, but in principle should there be an ok button, as per the set focal length screen?

4. Given that the camera system shortname is displayed in the main screen header, what is the purpose of the (non-shortened) camera system name? The person that created the custom camera system will have no difficulty recognising the former...because they created it. Is the latter superfluous?

Apart from that it's pretty good. :grin:
 

torger

Active member
I was expecting to downselect from a menu my cameras and lenses.
Is there a version running on a Mac computer?
No, there's no mac version, so I'm afraid you have to enter the lenses in the app. There's a zillion camera systems and lenses out there so to make dropdowns for them all was just too much work. If you think it's too tedious to enter them manually (you do it only once), a shortcut is to just adjust the sensor size of the generic system and keep the "generic zoom lens" and just adjust its range to include all focal lengths you have.

I'm aware that people are going to dislike this configuration step as it's not exactly fun, and I'm thinking of making some way to import from a computer so you can enter the info with a real keyboard. It's not too bad if you just do it though, the auto-completition feature on the smartphone keyboard helps a lot for repetitive names.

I have myself a preference for apps that are a bit more tedious to configure but in the end feels customized for my needs. Thus I like Rob's idea of being able to change the order of the scrollers.

Anyway, in addition to make lenses easy to copy I could consider to make dropdowns for at least common lenses, and then the rest you would enter manually. That is the add button would open a modal to show a choice to copy one a previously entered lens, or choose from a dropdown of common lenses, or create a new generic lens to edit (like today). The app doesn't require any internet permissions today, it's just a self-contained calculator. If enabling that I could consider making a cloud service for storing configuration but I'm not sure it's worth it... I'll think about it.
 
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f8orbust

Active member
I've been playing around with this since last night - like it a lot, particularly the sharp/soft edges to depth of field - something I hadn't come across before. Still getting to grips with the tilt screen.

Having a lens database for multiple bodies sounds neat, but in practice it takes just a couple of minutes to enter the lenses for each body. Unless you have dozens of bodies, it's a non-issue.

The scroll bars can be accessed easily enough with either hand (unless you have short thumbs and a huge smartphone), so their arrangement doesn't bother me either.

Thanks Anders !

Jim
 

k-hawinkler

Well-known member
Thanks. Right bow I have your app on an iPad, that's easier on my eyes.
Once I have entered data, is it easy then to transfer them to my iPhone?
Thanks again. (I have about 10 cameras and many, many lenses. :loco: )
 

AreBee

Member
Anders,

...you can always enter the lens again on the other system.
I don't like inneficient. :angel:

...a middle way would be to be able to when you add a new lens to pick from a list of lenses you've already entered for any system so it's easy to duplicate them.
Yes, a tick-list would be good.

...it would be easy to make the column order configurable...
This would be good.

Separately, toggling the Show sharp/soft CoC buttons seems to not do anything. Am I missing something?

Also, I appreciate I'm nitpicking, but given that depth of field is not solely a function of aperture, I consider that the selected aperture value should not be stated in the hyperfocal distance text in the main screen footer.
 

torger

Active member
Thanks. Right bow I have your app on an iPad, that's easier on my eyes.
Once I have entered data, is it easy then to transfer them to my iPhone?
Thanks again. (I have about 10 cameras and many, many lenses. :loco: )
Uh-oh, you're going to hate me now, it's not easy to transfer them to the iPhone as far as I know, I didn't implement any such feature at least. I didn't make it an "it's all in the cloud app", but for users with that many cameras I guess I should have... now it's just a self-contained calculator which doesn't even require access to the internet.

On iOS all apps automatically have access to internet, while on Android you have to ask for permissions, and many of us Android users have come to really dislike that every little app is wanting to access all sorts of resources so I made it a minimal permission app, the only permission it asks for is to vibrate the phone, which it does when it registers an angle measurement in the tilt screen.

I'll think about making it easier to enter lots of systems for those that have lots of them but unfortunately it's not a small feature but a rather big one so it will stay the way it is for a while.

If I were you I would focus on the high resolution gear you use to shoot landscapes which is where the app is most useful so maybe you don't need to enter all 10 cameras. You could always have one "generic" system too like the default, the possibility to enter your own systems is to make the app to feel more customized and cosy, but it's not strictly necessary. If you base your circle of confusion on airy disk, like the default is, you don't need to have the correct sensor size or pixel pitch either.
 

AreBee

Member
Anders,

If you base your circle of confusion on airy disk, like the default is, you don't need to have the correct sensor size or pixel pitch either.
If you enter the actual sensor pixel pitch, are calculated depth of field values more accurate?
 

torger

Active member
Separately, toggling the Show sharp/soft CoC buttons seems to not do anything. Am I missing something?
What should happen is that the pair of buttons on the main screen that are green and says "sharp" should disappear from the main screen, and you will always run in "sharp" mode. It works for me(tm). The idea is that if you don't use the feature you don't need to clutter the user interface with the buttons.

If you have then enabled the buttons are shown and then if you tap a green sharp one it turns into a red soft one. What happens is that you switch circle of confusion to the secondary "soft" one. You need to configure those to your liking. (You could configure them backwards such that the softer is actually sharper I have no such check, but it wouldn't make sense of course).

The purpose of this feature is to use it in cases when you really can't have enough DoF and you don't feel like stopping down further, but rather make the edges a bit softer without resorting to plain guesswork. A special aspect of it is that you can choose to only compromise one end, like the near edge if you only have big not-as-detailed structures close, or the far edge which may be a bit fuzzy due to atmospheric anyway.

For my sharp mode I have entered so small CoC that the edges are almost indistinguishable from the plane of focus even at pixel peep, while my soft mode is closer to a traditional larger CoC.
 

torger

Active member
If you enter the actual sensor pixel pitch, are calculated depth of field values more accurate?
The pixel pitch is only used if you configure the CoC to be related to pixel pitch. There's a discussion about this in the manual here: http://www.lumariver.com/lrdof-manual/#toc18

I've made some experiments and the setting I prefer is to indeed enter the pixel pitch and use the Max(Airy, Pixel) model, where the pixel pitch is used as a limiter on the lower end, 2.5x the pixel pitch, and the Airy disc is a limiter for the really small apertures at 0.5x Airy disc.

What the circle of confusion should be and be based on is really a matter of taste (and therefore often resulting in lengthy forum debates), so I've made the app really flexible in configuration in this case. "Accuracy" in this context is not meaningful as you have decided what the CoC should be, and the app then calculates the result.

There is an accuracy aspect though, and that is how well the thin lens model matches the actual lens construction. For ideal accuracy you should know the exact lens construction and have a precise model for that. It's 100 times overkill though for any reasonable distances. However in closeup it becomes more important, but this app is not intended for macro photography.

Note that the app adds the lens distance (roughly the focal length), that is measures all distances from the film plane (just like real lens distance scales), not the lens nodal point. The standard DoF formulas provide values from the nodal point, so you may see a difference there from some other calculators that provide distances from the nodal. As focal length usually is very short compared to the focus distance in this case it's rarely noticed though.
 

AreBee

Member
Anders,

It works for me(tm).
Yes, I have it now - I'm using an iPhone 4S and the small screen means that the buttons are off the bottom. Scrolling the screen upward reveals them, thanks.
 
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