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Birmingham, MI, 48009

248-229-2822

Metro Detroit and Michigan wedding photographer 

Education

Filtering by Category: photography101

Cheetah Softboxes Compared

Robert Hall

In my newest video I compared the 6 different softbox options available from Cheetah. 

This includes the Quick SoupBowl (QSB-26, QSB-34, QSB-42), Quick RiceBowl (QRB-36, QRB-48) and Max20.

26" QSB-26 https://bit.ly/2xngSL4
34” QSB-34 https://bit.ly/2Je8jqy
42” QSB-42 https://bit.ly/2L20NfP
MAX20 https://bit.ly/2xmLLzn
36” QRB-36 https://bit.ly/2LOhQTS
48” QRB-48 (quick out of stock, here's the rod version):
https://bit.ly/2JbL2Ws

Beauty Dish Plate for all quick softboxes: https://bit.ly/2seZ7Zz

Cheetah Rolling Boom Stand https://bit.ly/2ISgee0

Cheetah Low Profile Bowens Mount for AD600, AD600 Pro, H600B, H1200B, S Bracket (with screw replacement) https://bit.ly/2GXTmUj *select low profile option*

There's plenty of details in the video as well as my take on the difference, but I wanted to use an article as a place where people could view the images at their own speed.

Softbox Comparison

Quick SoupBowl QSB-26

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Quick SoupBowl QSB-34

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Quick SoupBowl QSB-42

DSC01981.jpg
DSC01982.jpg

MAX20 Parabolic

DSC01974.jpg
DSC01975.jpg

Quick RiceBowl QRB-36

DSC01983.jpg
DSC01984.jpg

Quick RiceBowl QRB-48

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Softbox Accessory Comparison

Empty Softbox

Empty-(dropped1stopfromjustdish)-1.jpg
Empty-(dropped1stopfromjustdish)-2.jpg

Beauty Dish Only

DishOnly-1stopPowerDrop(fromDish+Diffusion+Grid)-2.jpg

Dish + Outer Diffusion + Grid

OuterDiffusion-Dish-Grid-2.jpg
OuterDiffusion-Dish-Grid-1.jpg

Dish + Double Diffusion + Grid

DoubleDiffusedDishandGrid-1.jpg
DoubleDiffusedDishandGrid-2.jpg

Double Diffusion + Grid 

DoubleDiffusedNoDishwithGrid-2.jpg
DoubleDiffusedNoDishwithGrid-1.jpg

Double Diffusion

DoubleDiffusedNoDish-2.jpg

What do the F-stop Numbers Represent?

Robert Hall

An explanation of the mathematics behind the F-stop

When making the jump to manual photography, one of the most confusing topics can be that of the f-stop. Even after learning that the aperture controls your depth of field, you can still be very confused by why the numbers change the way they do. It's no surprise, as circle geometry isn't something you use in your daily life.

However, understanding the mathematics can give you an excellent grip on the f stop scale, especially if you're the left-brain type. Let's assume that you are already familiar with the full f-stop scale (1.4 - 2 - 2.8 - 4 - 5.6 - 8 - 11 - 16 etc.). Why is it that only increasing .6 from 1.4 to 2 is the same time of adjustment as moving 5 from 11 to 16?

chap2_apertures.jpg

 

The reason is that the f/stop number is actually a ratio between the diameter and focal length of the lens. The inverse relation of light stems from the diameter becoming smaller as the f/stop number increases. For instance, an 85mm lens at f/2 will yield a diameter of 42.5mm (85 / 2), If you stop down (increase the f/stop and reducing the light 1 stop) to f/2.8, the diameter is now  30.3 (85 / 2.8). Now I know what you are thinking, 30 isn't half of 43, so how did we halve the light if the diameter didn't get cut in half?

This brings us back to circle geometry. We need to look at the area of light that passes through the opening. The area of a circle is found by π x radius^2. The radius is half of the diameter, and pi is a constant that represents the circumference divided by the diameter. So, lets do the area math for the example above with the 85mm lens.

At F/2 we have a diameter of 42.5, and F/2.8 is 30.3. This gives us a radius of 21.25 and 15.15 respectively. 

So for f/2 we have π x 21.25^2 = 3.14 x 451.5 = 1418 square mm (rounded)
For f/2.8, its π x 15.15^2 = 3.14 x 229.5 = 720 square mm (rounded)

As you can see (while looking past some rounding), we have reduced the area of the opening by half. This is why when you increase the F/stop number  by one stop and reduce the size of the opening, you are reducing the amount of light that can get through by half. The ratio also explains while the numbers start to have bigger intervals as you move up the scale.

 

Hope this helps and please feel free to keep asking questions so I can provide you with more educational content!

Robert Hall is a professional photographer in Southeast Michigan. His work primarily consists of weddings, commercial and editorial. He is constantly improving his skills through discussion of techniques and critique with fellow photographers. Robert is always looking for new connections on social networks!

www.robhallphoto.com
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Twitter / Instagram: @robhallphoto