The Eg-S focussing screen – do you need it?

It’s a valid question. Here is my quick view of it. The screen I ordered landed on the kitchen table in an oversized parcel the other day. Inside the parcel was a small box, the size of a packet of cigarettes. As I have been using manual focus (MF) lenses for while an Eg-S seems to be the recommended path to take. But is it?

Replacing the old (Eg-A) screen of the Canon 5D2 was easy. In less than a minute the new one was in place. There is a small pincer tool supplied which helped a lot. Other than that there was really nothing special about it.


The Eg-S comes in a practical holder and a small pincer. Use the pincer to hold the new screen in the little square tab. Remember to save the old screen in the box. Make the change quick and keep it clean! No smudgy fingers! 

But, back to the question, is it worth it? Well, yes… and no. It depends really. The Eg-S screen is more matte and the viewfinder’s image supposedly pops slightly out when focus is correct. In focus the image is indeed somewhat clearer. However I find that the “pop” is not as distinct as I had hoped for.

With the old focussing screen almost all my focussing was with the help of the cameras built-in focus metering system, either with the centre focussing point or with the camera set in “live mode”:

  • With the built-in focus activated through the usual “half-press” of the shutter it is an easy task to rotate the focus ring of the lens until the viewfinder’s focus points flashes red. Easy, but slightly time-consuming.
  • In live mode, and 10x enlargement, setting focus is easy but one has to be careful to hold the camera still. At 10x even small shakes and vibrations of the camera body make the display’s image jump about quite a lot. For a tripod it is a no-brainer, but hand-held it is not always useful. The lower 5x image is not enough for precise focussing in my opinion.

My hope with the Eg-S screen was that I should be able to do away with the “half-press” and obtain a quicker focussing over all. In part this has come true, but, quite often I still get a better, and more precise, focussing with the “half-press”.

Another aspect of the matte Eg-S is that it consumes light. The viewfinder image is slightly darker when used together with my f/2 and f/2.8 lenses, and noticeably darker with an f/4 lens. The auto focussing mechanism in the camera does not seem to mind the less light, it focuses automatically even in darker scenes.

As the image in the viewfinder is taken with a full open lens the auto focus is guaranteed as much light as the lens can deliver. Only just as the picture is taken, the aperture is reduced to whatever the camera wants.

On the web I have read that using f/5.6 and slower lenses can affect the camera’s auto focussing ability as there is not enough light for the focus sensors. Apparently the slightly darker Eg-S screen and slow f/4 lens are bright enough in this respect.

But even though the auto focus does not mind the darker viewfinder I find the viewfinder image dark when taking pictures indoors. Outside shots in day-light is still no problem. But indoors and in dim light I’d rather use the brighter and original Eg-A screen.

So, as mentioned above, “it depends”. I am not dismissing the Eg-S screen  but it is clearly not the panacea I had hoped for. It is useful though and I will give it a serious try for the next few months. Changing back to the old screen is really easy so that will not stop me should I want to. At £40 incl pp it is perhaps a cheap way to experiment? Perhaps a focus screen with a split prism would be better?

Update: I started this text with intention to publish it in early spring. Time went by so this update includes the original too. A couple of days ago I switched back to the standard Eg-A screen. I found that I still used the internal focussing markers quite often, despite the matte Eg-S screen. In all these months with it, and the Voigtländer Ultron 40/2 attached, almost never did I rely on the focussing screen alone. YMMV of course.

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