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Using Your Hands as Focal Length Calculator

Canon 60d Takumar 85mm LensSince I have been using solely my prime vintage lenses for video lately, I have been wanting the capacity to pre-visualize what prime focal length lens I need for a specific shot. I want to be able to setup the tripod and know exactly what lens I need to mount for the shot I am trying to achieve.

Having been a photographer most of my life, you would think I would already have this skill. Unfortunately, I was used to relying on the functionality of a zoom lens, somewhat as a crutch, to help frame the shots I wanted.

To make things even worse, I am currently shooting with a Canon 60D which has an APS-C sensor and a multiplier of 1.62 for every one of my prime lenses printed focal lengths. Getting a “Full Frame” camera would fix the multiplier issue, but I am not very enamored by any of the full frame HDSLR camera offerings for video. And quite honestly, I would still have trouble being able to visualize the focal length being so out of practice at it.

Visualizing shot framing
Takumar 85mm Lens & Takumar 55mm Lens

There are a few different ways to determine focal length and frame width, including a director’s viewfinder (costs money), a smart phone application (costs money and distracting when working). Another no-cost option would be to simply practice more in order to get better at visualizing my shots and seeing the focal length without any aid at all.

I tried practicing more and was not very successful because I need some visual reference point to go by. This started thinking about the tools that we already carry with us everywhere we go. Here is where the arms, hands and fingers come in. After all the human body was one of the original measuring devices. Ever wonder why a foot is called a foot?

Most of us realize that the human body has certain dimensions, but here is the really cool part. Your hand and finger length along with your arm length tend to scale in proportion to your body for most people, roughly 95% of the population in fact.

Da Vinci Vitruve Luc Viatour - Human Body Visual Dimensions

Vitruvian Man by Leonardo da Vinci, an illustration of the human body inscribed in the circle and the square derived from a passage about geometry and human proportions in Vitruvius’ writings

Some of you might know the focal length rule that two hands equals 50mm and one hand equals 100mm. This still works great for full frame cameras, but when there is a multiplier involved, things start to get more complicated rather quickly. Many of us have also likely used our thumbs and fore fingers to approximate the 16×9 frame shape. Unfortunately, this shape does nothing to help determine lens focal length. You could move the “finger frame” in and out to approximate different focal lengths, but this quite variable less accurate than what I am going to share with you.

Using your hands to visualize framing

Using your arms, hands and fingers is an easy way to visualize the frame width for a specific lens making it a breeze to determine what prime lens you need for a certain shot. And once you know the frame width, approximating a 16×9 frame height, or any other frame height is a pretty easy task.

All measurements are done with your arms fully extended in front of you with hands tipped up at roughly 90 degrees. It is helpful to close one eye for determining the final frame width. Keep in mind the measurements scale according to each persons body and should be very accurate for around 95% of the population. If you fall into the 5% with short arms with long fingers or long arms with short fingers, you will need to adjust the measurements to compensate for your proportions.

The APS-C sensor size I am referring to in the table is the Canon sensor with a 1.62 multiplier, if you have a camera sensor with a different multiplier from another vendor such as Nikon or Panasonic, you will need to adjust the measurements. I have also included a table referencing “Full Frame” focal length hand measurements. Each photo can be clicked for a more detailed view of each hand position.

APS-C Crop Body Measurement Table

Lens
After 1.62
Multiplier
APS-C Sensor (1.62 lens multiplier)
Canon 60D, 7D, 70D, T3i, T4i
Hand Positions
18mm
29.16mm
Three hands wide at full arms length.
18mm Lens Frame Width APS-C Using Hands
28mm
45.36mm
Slightly less than two hands wide at full arms length.
28mm Lens - Frame Width APS-C Using Hands
35mm
56.7mm
One hand + width of one fist at full arms length.
35mm Lens - Frame Width APS-C Using Hands
50mm
81mm
One hand wide + width of thumb at full arms length.
50mm Lens - Frame Width APS-C Using Hands
55mm
89.1mm
Slightly less than one hand wide at full arms length.
55mm Lens - Frame Width APS-C Using Hands
85mm
137.7mm
Inside edge of thumb to tip of forefinger wide with hand in “L” shape, thumb up.
85mm Lens - Frame Width APS-C Using Hands
100mm
162mm
One fist with thumb out wide at full arms length.
100mm Lens - Frame Width APS-C Using Hands
135mm
218.7mm
One fist wide with thumb at side at full arms length.
135mm Lens - Frame Width APS-C Using Hands
200mm
324mm
Index finger knuckle to first joint wide at full arms length.
200mm Lens - Frame Width APS-C Using Hands
250mm
405mm
Thumb knuckle to first joint wide at full arms length.
250mm Lens - Frame Width APS-C Using Hands

Full Frame Body Measurement Table

Lens
Full Frame Sensor Canon 5D Mark II, 5D Mark III, 6D
Hand Positions
28mm Three hands wide at full arms length.
28mm Lens - Frame Width - Full-Frame Using Hands
50mm Two hands wide at full arms length.
50mm Lens - Frame Width - Full-Frame Using Hands
55mm One hand + width of one fist at full arms length.
55mm Lens - Frame Width - Full-Frame Using Hands
85mm Approx. One Hand + Width of Thumb at full arms length.
85mm Lens Frame Width - Full Frame - Using Hands
100mm One hand wide at full arms length.
100mm Lens - Frame Width - Full-Frame Using Hands
135mm Inside edge of thumb to tip of forefinger wide with hand in “L” shape, thumb up.
135mm Lens - Frame Width - Full-Frame Using Hands
200mm Length of index finger wide (knuckle to tip of finger)
200mm Lens - Frame Width - Full-Frame Using Hands

It was truly fun putting this post together and I hope some of you found it useful for helping to visualize your shots. Comments will be open for roughly 30 days and it would be wonderful to hear your thoughts on this topic. **Closing comments due huge amounts of SPAM. If you want to comment on this article, just drop us a message. Thanks!**

If you are looking for a simple follow focus or versatile camera stabilizer, but sure to check out our products page.

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What is in the Camera Bag for HDSLR Video?

What is in the Camera Bag for HDSLR Video?What is inside your camera bag for a video shoot? Here is a peek inside my camera bag before I head out to do some lens testing (Takumar vs. Canon) on a cold day. I am traveling on foot and thought you may find it interesting what I chose to include in my bag for this outing.

What is in your bag when you are headed out to do video? Share your recommended gear in the comments area below.

For anyone who is interested, items in the video are linked below:

If you found this post informative, please be sure to spread the word using one of the “Share this page” links below.

Using Takumar Vintage Lenses for Video with M42 to EOS Adapter

Awhile back I ran across an article about using older M42 lenses for video on newer Canon cameras with an M42 to EOS adapter. I was pretty excited because, thanks to my father in law, we have quite a nice set of old Takumar lenses.

Vintage Takumar Lens Set - 135mm f/3.5, 55mm f/1.8, 28mm f/3.5, 50mm Macro f/3.5 and 85mm f/1.9

Thinking about older lenses brought back memories of that buttery smooth focus ring on the old Canon FD 50mm prime used with my Canon FTB body. I can remember the moment I extracted the Takumar lenses from their leather cases and twisted the focus ring. WOW! I had forgotten how nice the older lenses were made.


I immediately bought an M42 to EOS adapter (without chip). Unfortunately, my current camera (Canon 60D) did not recognize that a lens was attached. I wound up needing to purchase the adapter with the chip, which worked perfectly. Keep in mind that these older lenses are completely manual and YOU will need to adjust the aperture and focus ring, the camera does none of it for you.

At this point I was getting really excited about using these older lenses for video, but it remained to be seen what kind of optical quality would be achieved. I assumed it would be pretty decent, but had not idea how nice of images from the older Takumar lenses would produce. One word “Fantastic!” The images are organic and the lens bodies are beautifully machined and they are truly a pleasure to use. Here is a shot testing lens flare on the Canon 50mm f/1.4 and the Takumar 55mm f/1.8

Canon 50mm f/1.4 @ f/1.8 and Takumar 55mm f/1.8 @ f/1.8 - Lens Flare Test

Wide open, the Canon 85mm f/1.8 beats the Takumar 85mm f/1.9 in sharpness (at least in my initial tests), but when reviewing the video, I actually think the Takumar 85mm has a more cinematic image. The Canon 50mm f/1.4 and the Takumar 55mm f/1.8 are very close in sharpness, and again I prefer the Takumar image over the Canon. I am manual focusing and using a variable ND filter which adds a layer into the mix, but these frame grabs should show how the lenses compare after small color correction. Also keep in mind that lighting is constantly changing and can affect the final comparison. Here a few sample frame grabs from some recent footage for non-scientific comparison (click any image to enlarge).

Canon 85mm @ f/1.8 vs. Takumar 85mm @ f/1.9Canon 85mm @ f/8 vs. Takumar 85mm @ f/8Canon 50mm f/1.4 @ f/1.7 and Takumar 55mm f/1.8 @ f/1.8Canon 50mm f/1.4 @ f/8 and Takumar 55mm f/1.8 @ f/8

Let me qualify this with saying that if you require auto aperture or auto focusing you will be disappointed. But, if you are shooting video on a DSLR, Cinema, or Mirrorless camera, these older lenses are so much better than the new offerings you will wonder why you had not tried them sooner. Seriously, some of the old Takumar lenses can be picked up for around $100 and in my opinion out perform their newer several hundred dollar counterparts in many ways.

First thing you will notice is the lenses actually have a focus ring that is super smooth when turned. No more jerky missed focuses, which can sometimes happen with the newer lenses when shooting video. Most of the older lenses also have more throw, meaning that they have more degrees of rotating between infinity and close focus giving you a finer level of focus adjustment. Many old lenses also have machined metal enclosures unlike the plastic lens enclosures that are so common today.

Takumar 55mm & 85mm -- Canon-85mm & 50mm

Most of the new lenses were built for fast, silent auto focus. The technology got so good that the camera manufactures no longer needed to focus on the manual capabilities of lenses as the camera computers were doing the adjustments so darn well. With the implementation of video into the HDSLR cameras however, users found themselves stuck with the new technology lenses, most of which are not ideal for smooth video focusing.

Canon recognized the need and reached for more technology to solve the smoother focusing needed for video. They began offering their STM lenses, which are focus-by-wire (computer driven focusing), and in my opinion leave a lot to be desired. Sure, with cameras like the new 70D and the firmware-updated 7D, these lenses can be very useful if you need the camera to do the work of focus tracking for you. But, unfortunately the STM lenses can be quite noisy and sometimes unpredictable in manual mode. The STM lenses can be especially annoying if you are needing to hit a specific focus point repeatedly during multiple takes, making them nearly useless to serious or semi-serious filmmakers.

Takumar 55mm & 85mm -- Canon-85mm & 50mm

Sometimes new technology is not the answer to solving our latest problems. There was a day not so long ago when lenses were built to last a lifetime. Those types of lenses now cost more than most independent filmmakers can afford. So, I say go “Old School” and take a look at some of the older manual lenses. Be aware thought that the old lenses will make your newer ones feel like toys. Two words, “Fisher Price”, now always come to mind when I forced to use my newer lenses, yes, even my “L” lenses.

Canon 60D with Takumar 85mm f/1.8 Lens

The Takumar lenses I am now using are in most cases, 50 years older than their more modern counterparts and I could not be happier with their performance. They produce great video images, are quality built, and have predictable focus rings that are buttery smooth providing the perfect complement to shooting video on any HDSLR, Cinema or Mirrorless camera. I just wish I had discovered that they could be adapted to my EOS camera sooner. They are now my go to lenses for video and travel with me everywhere.

Bottom line
, if you are looking for some great glass at a bargain price, look no further than some of the old vintage lenses. Your local pawnshop may even have a few jewels just waiting to be adapted to your camera. Keep in mind that older lenses from brands like Leica and Zeiss can be pretty costly while other brands like Takumar and Olympus can still acquired for a reasonable price.

Stay tuned: We are currently working on a video that will compare the Takumar 85mm f/1.9 to the Canon EF 85mm f/1.8 as well as the Takumar 55mm f/1.8 to the Canon EF 50mm f/1.4. We are not going to perform any scientific tests, but rather, we will be testing the lenses in real world shooting conditions and comparing the results.

Anything you would like to see done in our tests? Let us know by commenting below or contacting us and we will see what we can do.

If you found this post informative, please be sure to spread the word using one of the “Share this page” links below.

Lastly, you may also want to check out our Ultra-Simple Follow Focus, which helps give you more precise control of newer lens focus rings and also works wonderfully with the old manual lenses.

Cheers,
A. Spence
DSLR Solutions