Since I've primarily photographed with variable ND filters so far, I wanted to get a set with fixed values to give me even more flexibility. The filters have different darkening levels: ND8 - corresponds to 3 f-stops ND64 - corresponds to 6 f-stops ND1000 - corresponds to 10 f-stops To calculate the shutter speed, you simply multiply the time by the ND number. For example, if you have a shutter speed of 1/1000s and want to use an ND64 filter, you get a speed of 1/15s. An example: 1 / 1000 = 0.001 * 64 = 0.064s For times less than 1s you have to take the reciprocal, so: 1 / 0.064 = 15.624 which is a new shutter speed of around 1/15s You can work this out with a calculator, or you can use one of the many apps that calculate the whole thing very easily on your smartphone; you just have to enter the values. Alternatively, you can experiment a bit and after a while you will have enough experience that you can roughly estimate it without calculating. Alternatively, you can find tables online that you can print out and take with you. But enough of the theory. The filters make a very high-quality impression. Of course, you can buy filters like these in completely different price ranges and for a professional photographer who makes a living from them that might be fine, but for the average photographer who does it as a hobby or simply doesn't shoot in the high-end range, these filters are great. They are very flat, which has the advantage that you don't see any vignette in the corners of wide-angle lenses. You can even combine the filters to achieve even longer shutter speeds. Yes, you could even combine them with a variable filter. Generally speaking, you can set the right shutter speed for pretty much all common situations using these three filters alone. You can always compensate a little with aperture and ISO. When combining them, you just have to be aware that the filters add a bit of bulk to the front of the lens, and you may then have to expect vignetting with ultra-wide-angle lenses. I tested the filters with my Tamron 28-75m f2.8 and had no problems at all. The image quality is very good, especially considering the price. Getting three filters for just under €50 (at the time of writing this review) is a very good deal. You also get a case included, in which you can safely transport the three. The filters are simply pushed into the respective bag. You just have to be careful not to touch the glass when removing it, as you'll leave fingerprints on it. But with a little care, that's avoidable. For me, this is a fantastic set, and it deserves 5 stars. Of course, I can also recommend it. It's a good solution for beginners and advanced photographers alike. Professional photographers usually have their favorite brands and models of filters anyway.