After using some of the various focusing screens available for Pentax DSLRs it is time to put in writing how I really feel about some of them and the value they provide as well as some pictures to show how they look installed.
The short list of desired features:
- Bright clear screen
- Easily identifiable focusing aids
- Reference marks
- Relatively inexpensive
Some of the above requirements may force the selection toward one of the Chinese vendors on eBay. There are other options at various price points available to Pentax users.
Focusingscreens.com Ec-B: Specifications: - Made from Canon Ec-B full frame focusing screen
- Horizontal Split Image
- Concentric reference mark
Features: - Rule of thirds grid optional
- Comes in original packaging
- Additional thin spacers supplied
- Original screen installation tools
Price:
Approx $90 purchased direct from Focusingscreens.com
Package:
The Focusingscreen.com package arrived approximately eight days after ordering via US Mail to the east coast. Not only was all the original manufacturers packaging included but that was even repacked into a larger parcel. Short of completely crushing the box there is little chance that any screen received from Focusingscreens.com will arrive damaged. All the original documentation and tools are also included as well as a metal electronics tweezers and additional shims.
Installation instructions are provided online only but that is really not much of a hindrance as there are quite a few photographs of the entire process on their web site. There are also numerous YouTube videos showing precisely how to change a focusing screen on the various Pentax DSLRs.
The screen arrived clean and without any additional wear marks.
In Use:
If you have ever used an older full frame film SLR then you most likely have used a focusing screen that had aids for manual focus such as a micro prism annular aid and a split image area besides the matte. With today's DSLR being of the auto focus variety many manufacturers have only provided matte only focusing screen, although many have scribed marks to assist in locating the auto focus points. The problem with all matte screens is that critical focus of manual focus lenses cannot be achieved on a consistent basis. Pentax does offer additional focusing screen options on many of its DSLRs but other than different engraved marks they are all matte screens. This is where the aftermarket has filled the void.
This particular Canon Ec-B derived focusing screen has the addition of a horizontal split image and a concentric reference circle besides a laser cut echelette. Focusing manual lenses becomes an easy task with this particular screen. Auto focus is not affected by the installation of this particular screen. The matte area is bright and clear, it is a bit brighter than the OEM screen. The image appears to pop into focus. The split image is very accurate and can be used with an eyepiece magnifier for precision focusing. This is a welcome feature for high magnification macro shooters. There is no micro prism in this particular focusing screen.
I have used this screen extensively on one of my K20Ds with both very slow and very fast lens without any incompatibilities. One of the issues with split image areas is that one half tends to darken when slow lens are used. I was able to use this particular screen with a lens that has an f8 maximum aperture with no darkening at all. Fast lens have different problems usually associated with matte only screens, generally their depth of field is so shallow that on a matte only screen, where DOF is slightly exaggerated it is difficult to tell if you are precisely focused. The split image allows precise focus with little effort with even the fastest lenses that I had (50mm f1.4 and 85mm f1.4).
The reason that shims are provided is that these screens being built for other camera models may not be precisely the same thickness as the OEM screen. As long as the matte/fresnel surface is in the same position thickness of the screen is an insignificant factor in accuracy. The shims are provided so that the matte/fresnel surface of the screen can end up in the same place as the OEM. The use of the shims may not be necessary on some cameras.
One note about metering, with this as with all split image Spot metering is affected. It also varies based on lens maximum aperture and the actual shooting aperture. You cannot arbitrarily dial in a certain +- EV and expect it to work, Center weighted and Matrix metering seem unaffected.
The screen I ordered also included the "rule of thirds" lines to aid in composition. Please note that some screens might include architectural guides which divide the screen in quarters rather than thirds.
The bottom line:
I prefer this focusing screen to any I have tried up to this point.
- Pro:
- Good value at its price point
- High level of quality
- Ease of installation
- Con:
- No separate camera specific installation instructions included
- Spot metering is affected
Similar competing products: - Focusingscreens.com Nikon K-3
- JinFinance 45° split image
- Travor 45° split image
Out of focus: In focus:
Last edited by WheresWaldo; 10-21-2009 at 02:59 PM.