DOF Calculator Tool

DOC Calculator Tool in Magic ViewFinder apps is quite innovative yet extremely simple to use.

Once you press DOF button on the main screen you enter the DOF calculator:

You can set the values for focusing distance (the red line) and the apertures by moving the sliders.

Accordingly you can see the near and far limits of the sharp area (the blue lines) — the Depth-of-Field. The DOF doesn’t depend on the camera or the sensor you are using. That is why you should also adjust the focal length of the lens (the dark blue wheel on the right).

You can also see the Hyperfocal Distance value only if you have purchased Premium Features.

You can change the distance and the aperture simultaneously by tapping the screen:

NOTE: though the lines for the near and far limits of the DOF (the blue lines) seem to be equally away from the focus mark (red line) the actual distances are not equal (the vertical axis for the focusing distance is not linear).

If you turn on the BLUR MAP switch you can see a very important map of the blurriness:

The green area shows the size of the minimal sharp detail at any distance up to the infinity. The wider the green area is, the larger is the amount of the non-sharpness. In other words, anything smaller than that size will be totally blurred (sometimes this size is called the Disc of Confusion). As you can see the blurriness decreases as you approach the focus point, where it turns zero, and then it grows as it approaches the infinity.

To measure the size the Disc of Confusion turn on the CHECK switch (available only in Premium Features):

Now by tapping the green area you can read the exact size of the Disc of Confusion.

One example from the picture above: let’s assume that you have a paper with a word written on it. The letters written on that paper are 3mm tall. If your lens is set at the focal length of 58mm (the blue wheel on the right) and is focused at the distance of 3.24m (the red line) then if you place the paper at the distance of 1.27m from the camera (provided the aperture is f/10.9), the word on the paper will be blurred so that it can be hardly discerned. How do we know that? From the screen above the minimal sharp object at the distance of 1.27m is 3.2mm. Anything less will not be sharp.

Magic ViewFinder apps for iOS

Magic ViewFinder for iOS (iPhone and iPad)

Available now:

  • Cinema (Blackmagic cameras)
  • ARRI
  • Red
  • Canon
  • Sony
  • Nikon
  • Lumixus (Panasonic Lumix and Olympus)

Pre-visualizes the framing of digital cinema and photo cameras.

Intuitive design:


DOF calculating tool

Reference Mode (comparison of 2 formats)

Focus: auto or fixed

BW: auto, fixed or manual

LUTs: simple (bw, contrast, saturation) and professional (M31, Teal+Orange, etc)

Optical adapters (boosters) (x0.72 , x1.4 etc)

Frame guides and ‘golden section’ grid

Anamorphic lenses (1.33x etc)


Supports the following cameras:

Blackmagic Design:

  • BMCC
  • BMPC 4K
  • Micro / Pocket / Pocket 4K
  • URSA Mini Pro
  • URSA / Mini
  • URSA


  • Helium 8K
  • Weapon 8K
  • Scarlet-W
  • Weapon Dragon
  • Epic Dragon / Mysterium-X
  • Scarlet Dragon / Mysterium-X
  • Red One

Comments  may be sent to:email


Welcome to my mobile apps

Currently there is one iPhone / iPhone app and three Android apps that I developed to make life easier for photographers and cinematographers:

Magic ViewFinder (iOS and Android) is Director’s ViewFinder simulator. This app generates view that will be seen through your camera. It is NOT an external viewfinder for any camera. It is designed to be used in a stand-alone smartphone / tablet.

Magic ViewFinder is actually a range of apps, each supporting a system, among which are: Canon, Nikon, Sony, Lumix, Red, ARRI and, last but not least, Black Magic Design. These apps are free, as opposed to the Magic Universal ViewFinder app, which is paid, ad-free and has some nice additional features.

Visual DOF is a depth-of-field calculator at first glance, but it is much more than that. The app generates a preview of how (non) sharp any objects will look, that happen to be (or not) near the point of focus. More than that, the app measures the blurriness for you, and makes a huge sense from these values.

Magic Light Master is a tool for those who want to master exposure of light. This app takes the data from measuring by professional tools, like Sekonik light meter, and graphically displays them on characteristic curves. Also this app has White Balance meter which is handy at shooting, and some technical references for different cameras.

Magic Light Master is yet in pre-release version 0.9.9.


-Roman Medvid

Android Software Developer

PS If you want to sell your images and video footage via stocks, I do recommend Shutterstock. Time means a lot there, so the sooner you upload your works, the sooner they start bringing you some coins.


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Magic ViewFinder – Specifications

Black Magic cinema cameras:
Production 4K, Micro Cinema, Pocket, URSA 4.6K / URSA Mini, URSA

Canon DSLR and video cameras:

  • Full frame cameras: 1DC, 5D Mark II/III, 6D (16:9 HD and 3:2 photo modes)
  • Cameras with cropped APS-C sensor: All Rebels / 750D, 600D, etc / 70D, 60D, 50D, etc (16:9 HD and 3:2 photo modes)
  • EOS C100/C300/C500
  • XA10/XF100

Nikon DSLR cameras:

  • Full frame camera: D4s (16:9 HD and 3:2 photo modes)
  • Full frame cameras DXX0: D810,  D750, etc.(16:9 HD and 3:2 photo modes)
  • Cameras DXX00 with cropped APS-C sensor: D7200, D5500, D3300. etc. (16:9 HD and 3:2 photo modes)

Panasonic Lumix cameras:

  • GH4 HD (16:9 HD / 4:3 photo / Cinema 4K modes)
  • Other 4/3 cameras (GH3, G7, GF7, etc)
  • 1″ sensor cameras (for example, FZ1000)

Sony cameras:

  • Alpha R7II (16:9 HD and 3:2 photo modes)
  • Alpha 7II, 7S, 7, 7R (16:9 HD and 3:2 photo modes)
  • Alpha 77, 5100, 6000 (16:9 HD and 3:2 photo modes)
  • Sony F3/FS7

Red cameras:

  • Dragon Weapon / Epic / Scarlet
  • Mysterium-X Epic / Scarlet
  • Red One camera

Alexa Classic and XT cameras:

  • Classic / sensor mode 16:9 / ProRes HD, DNxHD, ARRIRAW / ProRes 2K
  • Classic / sensor mode 4:3 / ProRes 2K, ARRIRAW
  • XT / sensor mode 16:9 / ARRIRAW, ProRes HD, DNxHD / ProRes 2K / ProRes 3.2K
  • XT / sensor mode 4:3 Full / ARRIRAW, ProRes 2K
  • XT / sensor mode 4:3 Cropped / ARRIRAW
  • XT / sensor mode OpenGate / ARRIRAW

Phase One Digital Back (Photo Medium Format)

  • Phase One P30/P40

Should you feel other cameras should be supported, please feel to contact me at:
my email
Or leave your comment on Guest book – NO REGISTRATION REQUIRED

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Calibrating your Android device

So you will need to calibrate the camera in your Android device if:

1. You bought a wide lens adapter for your camera, something looking like one of these:


2. Or you want to make sure that the Magic ViewFinder app has the most precise data about your built-in camera.

Calibration is a very simple process that will take 3 minutes. So do it, and it will be good for you.

1. Place your Android smartphone or tablet vertically on a flat surface, the floor or a table. The camera should be aimed horizontally, not down or up. I usually just squeeze my smartphone in between heavy books.

Placing the phone
Placing the phone

2. Launch your standard Camera app in the device and make sure it is producing the image in 16:9 full screen ratio, not 4:3. (Also, if your Camera app has zooming function, zoom out as wide as you can).

Select the HD (16:9) mode
Select the HD (16:9) mode

3. Now place 2 objects on the surface in front of the camera so that they come close to the left and right edge of the frame on the device screen respectively.

Two objects 'touching' the side borders of the frame
Two objects ‘touching’ the side edges of the frame

4. Measure the distances between them,  and also between the lens of the built-in camera and each of the objects (you get three values). You are almost done.

Start measuring the distances
Start measuring the distances

5. Switch to Magic ViewFinder app, go to Menu > Calibrate device > Calibration Guide. After 2 slides with explanation about the calibration process, you will get to the page where you must enter the measured distances. The page pretty obviously tells you to do that. Having entered the distances (in centimeters or inches), press Calculate the angle. Done! You can see the angle in degrees now. Press Set.

Enter the distances and press Calculate
Enter the distances and press Calculate

Now Magic ViewFinder will keep this angle value until you decide to change it.


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Magic ViewFinder

The family of Magic ViewFinder apps are actually a camera for your Android device, which simulates the exact frame for the particular camera and the lens.

Please note that it is a simulator of the device called Director’s Viewfinder that helps the Director see exactly what will be shot, without making the camera man give the place to the Director at the real camera.

Stanley Kubrick using a director’s viewfinder on the set of “The Shining” (1980).

The Magic ViewFinder app is by no means designed to be an external viewfinder for your camera. Don’t try connect your phone to the camera, it won’t work. I warned you 🙂


Presently there are Magic ViewFinder apps that support Canon, Nikon, Sony, Panasonic Lumix, ARRI, Red and Black Magic Design cameras. You can browse the full list of supported systems and cameras.


The main screen of the app is pretty simple: it’s a view that you would see in the specific camera through a specific lens.

User interface ver 2.3.6
User interface ver 2.3.6

You can change the camera through menu. You change the focal length of the lens by rotating the wheel on the right.

Also available are various optical adapters  (tele converters or wide ‘boosters’) frame guides, anamorphic indexes that you  can change through the menu. The on-the-screen controls include exposure lock and auto focus on/off switch. This video (though for an older user interface) demonstrates the operation:


If you are planning future shoot on a location, you may want to capture all the important image references as a planning process. You can use ‘Capture’ button to store exact framing with the metadata burnt into the image. All shots will be stored in the folder Pictures > Magic, immediately available from within your Gallery app. The captured image will look like this:

Captured image ver 2.3.6
Captured image ver 2.3.6

 Free / Paid Versions

All Magic ViewFinder apps are free, except for the one called Magic Universal ViewFinder. When you buy the paid version you will get:

– ad-free interface

– all cameras in one app: ARRI, Red, Blackmagic, Sony, Canon, Nikon, Panasonic

– all optical adapters (wide and tele)

– all frame guides (like 1.85:1, 1.66:1, etc)

– all anamorphic indexes, enabling you to preview anamorphic lenses

– all sticky values on the rotating wheel will be kept after you leave the app

– additional settings (like vibration on/off, large/small size of the image, etc).

I also carefully listen to the feedback / suggestions regarding your needs, so your purchase of the app (not huge amount of money) will encourage me to keep improving it.

Please note one potential issue with an Android device. Usually the camera in your Android device is not producing extremely wide views, usually the horizontal view angle is about 60-70 degrees wide. So, when the view must be wider than that of your Android device, you will see pink margins around the image, representing the margins that the Android camera cannot capture:


To improve your experience with Magic ViewFinder app on your device, I recommend that you buy a wide lens adapter for your smartphone. It will make the lens significantly wider, and may be one looking like these lenses:

Clip wide lens adapter

When you have bought it and applied to the your phone, you basically changed the focal length of your built-in lens. So now you will need to calibrate your phone / tablet. You also need to calibrate your built-in camera if you feel that your device gives mistaken information to Magic ViewFinder app, making it produce a wrong view. Well, welcome to Calibration process

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