Skip to main content

Circular ND filters vs square ND filters

Good quality digital photography accessories can easily make a photograph look different. After tripods and flash units, one common accessory that can completely change the look of a DSLR photo is filters. Filters can be considered as a fairly good option if you are looking to improve your photography skills. Various types of photography filters include polarizers, infrared, neutral density and UV filters. To maintain the simplicity of this post, we will focus on neutral density filters only.

A neutral density filter is nothing but a piece of dark glass. The purpose of a neutral density filter is to reduce the amount of light entering the camera lens and thus hitting the sensor. ND filters with a constant density of darkness throughout are known as constant ND filters whereas ND filters with variable density of darkness are known as variable density ND filters. The density of darkness offered by a variable ND filter can either be smooth or hard. 

Square filter or circular ND filter

Let's focus on the shapes of ND filters. A neutral density filter can either be circular or square in size. Some ND filters come in a rectangular shaped glass too. Circular ND filters are also known as screw on filters as they can directly be screwed onto the lens thread. Square shaped filters do not have any thread, and therefore need a filter holding unit that gets attached to the lens. The filter glass along with light leak gasket can be pushed into the slot offered by lens holding unit. The image below shows my ND 3.0 filter from Haida. ND 3.0 means it is a 10 stop neutral density filter. If you want to know more about ND filter naming, here is my previous post about the naming nomenclature of neutral density filters.

Circular vs square nd filters

Most of the square-shaped neutral density filters come with a rubber gasket attached to them on the backside. The purpose of the rubber gasket is to prevent any light leakage when doing long exposures. The image below shows a generic holding unit for square shaped filters. The metallic part on the top is spring based and gets locked onto the ring attached to the camera lens.  This ring varies in diameter depending on the lens thread size. Example: 58 mm, 77 mm, etc. A 77 mm lens will need a different ring, but the same holder unit and ND filter can be used. So you see the advantage part now? No need to buy new filters again just because you upgraded to a new lens. All it needs is a threaded ring to hold the attachment for ND filter.

Circular ND filters vs square ND filters

Both screw-on and square ND filters perform the same role, but like any other photography discussion, which one is better? When it comes to circular ND filter vs square ND filter talk, here are a few advantages of a circular screw on ND filter:
- Easy to use and carry. Being smaller in size, circular ND filters are easy to carry around.
- Fewer chances of breaking.
- A variable density circular ND filter darkness level can be changed by rotating the filter. This doesn't apply to fixed density ND filters where the darkness is same throughout the filter.

Advantages of square ND filters:
- Cheaper longer term. It is easier to adapt to various lens sizes with a square-shaped filter.
- Less interference and vignetting.

Hope this post helped you to learn something new about filters. Based on the above discussion, which filter are you going to buy? Share in comments.
Reactions:

Comments

Post a Comment

Popular posts from this blog

Canon CR3 raw format guide

A raw image file is like a digital negative without any lossy compression and minimal processing applied to it. A digital camera shooting images in raw format provides output in the best possible quality, which means files are larger in size and take more space. The benefits offered by shooting raw format overpowers the slight storage hassle though. Few of the well known raw formats include CR2, NEF, RW2, RAF, PEF, ARW, etc.  In this post, we will talk about the new compressed raw format introduced by Canon starting with its mirrorless series of cameras.


History of Canon raw formats
Back in the early 2000s, Canon cameras produced raw photos in CRW format. Cameras shooting in CRW include Canon D60, Canon D30, Canon 10D, and Canon EOS 300D. Most of the cameras released after the year 2004 shoot raw photos in CR2 format. Examples of CR2 format Canon cameras include 350D, 6D, 7D, 5D, 5D Mark II and many more.
In 2018, Canon introduced its new mirrorless camera known as the EOS M50.  This …
12 comments
Read more

Relation between ISO, shutter speed, aperture and light in photography

Photography is a word having Greek roots, which basically means "drawing with light". When I started doing digital photography a few years ago, this did not make sense to me at all. How can you make a picture just using light? Only light matters? My pictures were either black or completely washed out all the time, but I didn't feel like giving up. It took me a fair amount of time to understand controls such as shutter speed, aperture and ISO which was the outcome of non-stop reading and a lot of mistakes. Coming back to the concept of light, it started to make sense after attending a film photography workshop. The dark room with very dim or near to zero red lights was a whole new point of interest. My partner and I made a pinhole camera out of a pumpkin. 
The workshop made me understand how important light is when taking pictures, and the rules apply to both film and digital photography. Basically, the value of shutter speed and aperture directly affect the amount of li…
2 comments
Read more

F2.8 vs F3.5 vs F4 lens aperture comparison with examples

I started the exciting journey of digital photography with 18-55 mm kit lens as my first glass. Being a variable aperture lens, it has a minimum aperture of F3.5 at 18 mm. The lens saw its fair share of adventures and ultimately was replaced with a fixed aperture lens.   Value of aperture is a part of the exposure triangle, which means it affects the amount of light hitting DSLR camera sensor. In addition to light, it also affects the amount of area in focus which is often referred to as Depth of Field. An image taken at F8 will have almost everything in focus when compared to an image taken at F2.8. Before someone jumps on me with their DOF vocabulary, this post is not about depth of field (DOF) in detail discussion. It is a simple comparison post for beginners to understand how lens aperture impacts background blur and low light performance. 
DSLR used: Canon 6D Lens used: Tamron 24-70 mm F2.8 DI VC USD
Bokeh (background blur) comparison:

Comparison animation in the above photo show…
Post a Comment
Read more