Filters discussed on this page may have a thread size (i.e., diameter) larger than 28mm. In fact, they are either of 37mm, 39mm, 43mm, 46mm or even 49mm. Hence, appropriate step-up rings are required, and, as a result, effects created with these larger filters may not fit completely on the image. Moreover, since step-up rings may block the flash sensor, using these filters may prevent you from using internal/external flashes. Proper exposure compensation applied to the camera and/or flash may be required.
Diffusion filters are used to create soften images. The keywords are enchanting, romantic and dreamy. Basically, a diffusion filter diffuses strong light without affecting the sharpness andcontrast of the image. Thus, it is different from the effect of out of focus. Diffusion filters are mainly used in portrait work. In general, small skin defects can be eliminated almost completely, and facial contrast and wrinkles are soften. To create a better result, aperture should be opened up so that the subject can stand out well against the background. Unfortunately, for a 950/990/995 it is difficult to achieve this large-aperture effect we normally enjoy with a 35mm or 120 camera except in the close-up mode.This is partly because the largest aperture of 950/990/995 is not large enough.However, we still can achieve reasonably good results. Your subject should be well lighted; otherwise, diffusion effect will not be so great. Also avoid very harsh mid day light because diffusion could wash out all the details.
| Top Row: Hoya Duto, Tiffen FX, co*kin Sunsoft, co*kin Diffuser Bottom Row: B+W Soft Focus 1, B+W Soft Focus 2, B+W Soft Image | ||
| Click on the icon to see a larger image | ||
The above shows a number of diffusion filters, each of which is either named as a soft-focus or as a diffuser filter. In general, diffusionfilters contain some mechanism built into the filter for dispersing the incoming light. Filters like Hoya's Duto and B+W's Soft-focus 1 and 2 have concentric circles etched into the filter surfaces (i.e., the Duto construction method). The density of these circles determines the softness ofthe resulting image. Others, such as B+W's Soft Image, co*kin's Diffuser and Tiffen's Soft/FX, have different etched patterns. These patterns may contribute their own patterns to the formation of foreground and background.See the last section on this page for some details.
The right image below was taken with a Tiffen's Soft/FX #3 filter. Compared with the left one it shows clearly that the use of a diffusion filter producesa much better skin texture than the one without. Also note the the "glowing" effect of the highlight and bright areas,and the diffused background.
| Without diffusion filter | With diffusion filter |
| Click on the icon to see a larger image | |
The following are more examples of different diffusion filters.The co*kin Sunsoft adds a touch of sunset gold, B+W Soft Focus 1 is of Duto type and creates a soften background with a very weak touch of the co*kin Radial Zoom effect, andB+W Soft Image produces a soften image weaker than that of B+W Soft Focus 1.
| co*kin Sunsoft | B+W Soft Focus 1 | B+W Soft Image |
| Click on the icon to see a larger image | ||
Effects of Diffusion Filters
Not all diffusion filters deliver the same result. Filter manufacturers makea number of diffusion filters of various degree. For example. Tiffen has Soft/FX filter #1 to #5; but, only #3 is available for 37mm thread size.B+W has Soft-focus 1 and 2, and Soft Image. co*kin has Diffuser 1, 2 and 3,and a Sunsoft which produces diffused images with a touch of sunset gold color.The following images show the effects of using different diffusion filtersunder a uniform illumination environment. Compared with the one that did notuse any filter, all other images have slightly lighter tone due to the spreadingof light. Hoya's Duto has the lightest effect. This is followed by Tiffen'sSoft/FX and B+W's Soft Focus 2. In terms of the strength of the diffusioneffect, B+W's Soft Image is slightly stronger thanB+W's Soft Focus 2, and is weaker than B+W's Soft Focus 1. I would say theseare of the soft-focus type that does not degrade the sharpness ofan image. On the other hand, co*kin's Diffuse 2 is a diffusion filter thatspread the light into the darker areas, creating a very soft and diffusedimage. co*kin's Sunsoft is similar to that of Diffuser 2, and adds asunset golden touch.
| No filter | B+W Soft Focus 1 | B+W Soft Focus 2 |
| B+W Soft Image | co*kin Diffuser 2 | co*kin Sunsoft |
| Hoya Duto | Tiffen Soft/FX 3 | |
| Click on the icon to see a larger image | ||
The next few images show the effect of diffusion filters under sunlight.Compared with the image taken without a filter, we immediately notice thatthe images taken with B+W's filters reduce contrast to some degree. Hoya'sDuto also reduces contrast a little which is comparable to that of B+W's SoftImage. It is clear that of the three B+W filters, the strongest is Soft Focus 1 and the weakest is Soft Focus 2 with Soft Image in the middle. Hoya's is similar to that of B+W's Soft Focus 2. co*kin's Diffuser 2 and Tiffen's Soft/FX #3 both show a nice "glowing" effect which does not appear inall images taken with the Duto type filters (i.e., B+W's Soft Focus 1 and 2, and Hoya's Duto). In terms of the diffusion effect, co*kin's Diffuser is the strongest, and Sunsoft produces a beautiful touch of sunset gold.Which one is the best? This depends on the situation and your need.But, if you are careful, you will notice the background in all of theseimages are different! So, you might want to take thisinto consideration when choosing a diffusion filter. Please continue withthe next section to see more details about background.
| No filter | B+W Soft Focus 1 | B+W Soft Focus 2 | B+W Soft Image |
| co*kin Diffuser 2 | co*kin Sunsoft | Hoya Duto | Tiffen Soft/FX 3 |
| Click on the icon to see a larger image | |||
But, Not All Diffusion Filters Are Created Equal
While all diffusion filters soften the subject to various degree, backgroundis another story. In fact, the construction of a filter dictates the impacton the background. The following is an image without using a filter.The portion of the background that will be examined carefully is marked witha yellow rectangle.
The following images are the original, untouched portion of the same scenetaken with various combinations of diffusion filters. The first impression when looking at these images is that Hoya's Duto and B+W's Soft Focus 1 and 2filters reduce the contrast and tonality of the original. When filters arecombined, this becomes even more obvious. See the images taken with both B+W'sSoft Focus 1 and 2, and the one with B+W's Soft Focus 2 and Soft Image. B+W's Soft Image and Tiffen's Soft/FX #3 maintain the contrast and tonality very well, and co*kin's Diffuser also does a good job. So, it appears that Duto type filters do lower the contrast and change tonality a little because the concentric circles spread the light into the shadows.
| No filter | Hoya's Duto |
| B+W's Soft Focus 1 (Duto) | B+W's Soft Focus 2 (Duto) |
| B+W's Soft Image | B+W's Soft Focus 1 and 2 |
| B+W's Soft Focus 2 and Soft Image | co*kin's Diffuser |
| Tiffen's Soft/FX #3 | Two Tiffen's Soft/FX #3 |
| Click on the icon to see a larger image | |
The etched patterns of a diffusion filter also contributes to the formationof the background. For the Duto type filters, the Hoya Duto has a backgroundsimilar to the original; the B+W Soft Focus 2 blurs the background; andB+W Soft Focus 1 produces a regular pattern which is even more visiblein the image using both Soft Focus 1 and 2. I suspect this pattern is actuallythe image of those concentric circles, and the offset of these circles of the Soft Focus 1 makes them very visible.
B+W's Soft Image filter has many circular patterns scattering in the filter.These circular patterns produce a not very pleasant background as can be seenabove and in the full images in the previous section. This pattern issoftened a little when Soft Image and Soft Focus 2 are combined.Tiffen's Soft/FX has many randomly etched short arc patterns. As a result,the background shows a quite regular interweaving line pattern. This situationimproves when two Soft/FX filters are used.Finally, co*kin's Diffuser 2 has a very densely etched pattern. Perhapsbecause the pattern is so dense, this filter does not produce any particularpattern in the background. Hence, it appears that only co*kin's Diffuse 2produces a patternless background.
