Recently, I picked up a Nikon D7000. One of the things I was excited about was the D7000’s ability to shoot video. But, soon after I made the purchase, I knew I was going to want a variable neutral density (ND) filter or fader. A variable ND is a filter used to decrease the amount of light reaching your camera’s sensor without changing the color hence the “neutral” part. The “variable” part is made possible by sandwiching a circular polarizer in between your lens and a linear polarizer. You can then spin the linear polarizer to adjust how it’s oriented to the circular polarizer and this gives you the ability to make it lighter or darker.
Now, why did I want one of these magical devices? Well, have you heard of the 180 degree shutter rule as it applies to shooting video? The 180 degree shutter rule states that your shutter speed should be 1/(2(frame rate)). This means that if you’re shooting at 24fps your shutter speed should be 1/(2×24) or 1/48… or 1/50 if you’re using a dslr. If you’re shooting at 30 fps, or 29.97 your shutter speed should be 1/60. The reason you do this is because each frame of video requires a certain amount of blur to help blend the frames together. If you use too long of a shutter speed there will be too much blur and the video will take on a smeary look. If you shoot faster than the 180 degree rule suggests the video will have a staccato effect. Neither of these types of effects are “wrong” they will just look less than natural, and should only be used when you have a good reason. For all the other times you should use the 180 degree rule.
So why did this rule have to do with me wanting a variable ND filter? Well, if you’re capturing video you’re most likely to be shooting at 24 or 30 fps. These frame rates are relatively static, so that means that you’re pretty much stuck with a shutter speed of 1/50 to 1/60. Even at ISO100 you are going to run into a lot of situations when there is too much light for you to be able to use a large aperture .
With a fader this problem goes away. With a fader you can use a large aperture like f2.8 or f4 and adjust the filter to bring your exposure back down allowing you to maintain the nice shallow depth of field that makes everyone so happy in their pants.
The Actual Review
So, with that out of the way we are now ready for the review. Here I will be discussing the performance of the Fotga Slim Fader Variable ND Filter. When I first started looking at variable ND filters I wasn’t surprised to find that most of the well recommended versions from recognizable brands cost a fortune. For instance a VariND from Singh-Ray costs ~$400! Now, I’m sure that this is an amazing filter, however at 1/3 the cost of my camera I just could not justify the expense and figured there had to be a cheaper option.
So, I started looking around and found versions in the $50-$75 neighborhood and eventually stumbled upon the Fotga Slim Fader ND over at CheesyCam. These filters were so cheap I figured that even if I ended up using it once and then throwing it out it was at least worth a try. So, I jumped on Ebay and ordered the 77mm model. It took a couple of weeks to show up, and when it did I was disappointed to find that it was the wrong size. The model delivered was the 72mm model with 77mm outer threads. I double checked my order, and sure enough I had ordered the 77mm model with 82mm outer threads.
So, I contacted the seller FotoForEasy. They were very quick and easy to communicate with and in the end they let me keep the 72mm model and sent out the correct one with 77mm male threads at no charge. I’m sure it was just an honest mistake on their part and should not reflect poorly on them. They realized their error and were very quick to choose a course of action that solved my problem and inconvenienced me the least. I would definitely shop with them again.
Anyway, back to the filter.
This review is of the 72mm model as I have not yet received the 77mm version. Since not one of my lenses has 72mm threads I picked up a 52-72mm step up ring so that I could mount the filter on my nikon 50mm f1.8 and 35mm f2.0… so far I’ve been very impressed.
Please keep in mind you are putting two pieces of polarized glass between you and your subject, so no matter what you do there is going to be slight degradation of your image. But as you can see in the images above the level of degradation is very minimal and, in my opinion, totally acceptable.
The image on the left was taken without a filter, while the image on the right was taken with the Fotga Slim Fader and collapsible rubber lens hood. I then imported the raw images into Lightroom, dropped the blacks to 0 and the contrast to 0 and then exported as jpegs. As you can see the image with the slim fader is a little more saturated. This is from the effects of the polarizer. Also, if you take a close look there is a slight decrease in sharpness, but again it is very slight.
Overall, I have been very impressed by the quality of the filter and the service provided by FotoForEasy and would definitely recommend this product to anyone looking for an inexpensive variable neutral density filter.
Anyone out there have any thoughts? Let us know in the comments section.