Is it my eyes, is it in focus?

graham reed

Author: graham reed

Published: 01 May 2015

by Graham Reed Issue 100 - April 2015

Is it me or as I get older, and my eyes not as good as they were, are viewfinders getting smaller and less sharp?
When I started as a cameraman the cameras were large (EMI 2001\'s) as were the viewfinders. They were large format cameras with a 30mm 4x3 sensors and the normal aperture was f 3.5, so a shallow depth of field, and it was easy to see focus. They had 6 inch black and white viewfinders with great contrast and good peaking controls, even though being what is now called standard definition, 625 lines, you could really see when the picture was sharp.
Then along came ENG cameras (SD) with small black and white CRT viewfinders but they did have a lens so you could see a nice sharp picture so you could put your eye in the eye cap when in bright light and have no problems when using them outdoors.
One of the earliest handheld cameras was the Ikegami 75D with small pick-up tubes but they were great cameras! Then came HD cameras, remember DigiBeta at around £22k per camera? At first they also had black and white viewfinders, really sharp, but very soon the manufacturers brought out new models and put a colour monitor on the side of the camera which could either display the sound levels, time code etc., or be switched to camera output. But apparently users demanded colour viewfinders whilst at the same time the cameras became smaller and cheaper. But why do we need colour v/f\'s? Is it that the camera person of today can\'t do white balance and needs to see the picture in colour? Apparently according to the manufacturers, yes. So we now have low resolution colour ones. Some cameras do not even have an eye piece so seeing the v/f outside in sun is impossible!
The eye sees sharpness because of contrast and a black and white image will always appear sharper than a colour image. This is because in the retina there are two types of photoreceptors, rods and cones. The rods are more numerous, some 120 million, and are more sensitive than the cones, it is because of these we see the black and white image and because there are many more it is these that give us the sense of sharpness.
The cones which are far fewer give us a sense of colour, but because they are less sensitive it is why we do not see colour at night.

There are camera operators who do not know how important it is to set up the v/f correctly so as to judge exposure properly, I was talking to one recently who just adjusted the brightness depending on how bright the prevailing conditions were! This is why the ITTP, Institute of Training in TV Production, is setting up the \'Approved Skills\' initative so that those entering the industry can be evaluated on their skills and knowledge, like setting up a v/f!
Modern camcorders, for example, have a v/f of 640 x 480 almost half of the resolution that we had 30 years ago, but because this is made out of \'dots\' nothing ever looks sharp. Not only that but the picture area is tiny, checking focus in a wide shot when the subject is small is impossible.

Some more advanced camcorders offer a v/f of 960 x 540. This is for an HD 1920 x 1080 picture so half the picture resolution, but no problem, you can magnify the image to check focus, but you are still seeing a picture of small dots. Is there really time to do this, especially if you are running around hand held! I want to really see the focus just like the old days of DigiBeta, not just a low resolution colour picture made up of lots of little dots! But how will we fare with 4K?
Will the v/f be twice as sharp? What I have seen so far is that they are mostly the same v/f\'s, so we now have images with twice as much resolution but with v/f\'s displaying only a 1/4 of the resolution. The problems of focusing becomes even harder with 4k because we have halved the depth of field so we need 4K viewfinders. I have a suspicion that some camera manufacturers may have just put a 4k sensor in a 2k camera body leaving much of the basic camera the same, same lens and same v/f.
If you look at the specification for 4k cameras they will go in to great poetic description about how great the camera is and how it can \'deliver stunning cinema quality recording\' and how it can record in many different compression systems, but down at the end of the specification list it will say it has a 3.5 inch v/f with 920,000 pixels, sounds alot, right? I get the idea that as the resoultion is so low they they don\'t actually want to give it! So that is only just over 306k pixels per colour and you will be able to see focus in 4K?!
So question, do we the user really want low resolution colour viewfinders, why not just very sharp black and white ones - they may even be cheaper!


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