Viewfinder: optical and electronic, pros and cons | Articles | Photo, video, optics

The viewfind­er is the win­dow through which the pho­tog­ra­ph­er looks at the world. At least when it’s film­ing. There are viewfind­ers that real­ly are just a hole in the body, cov­ered with glass, there are more com­plex designs with mir­rors. There are those who only pre­tend that they are a hole, when in fact they are a screen. Read more about dif­fer­ent viewfind­ers in this text.

Viewfind­er of an old film cam­era with the pen­taprism removed / Pho­to: unsplash.com

Opti­cal viewfind­ers
Mir­ror viewfind­er
Tele­scop­ic viewfind­er
Range find­er
Elec­tron­ic viewfind­er

Mirror viewfinder

The most com­mon opti­cal viewfind­er today. The design of the viewfind­er is almost the same as it was in the days of film DSLRs. The light pass­es through the cam­era lens and hits the mir­ror (1). Most of the light is reflect­ed from the mir­ror, enters the pen­taprism (3) and enters the pho­tog­ra­pher’s eye through the eye­piece (2). Well, a small part of the light beam pass­es through a translu­cent area in the cen­ter of the mir­rors (1), and with the help of a small mov­able mir­ror it hits the aut­o­fo­cus sen­sors (5).

SLR cam­era viewfind­er dia­gram / Pho­to: tehnika-soveti.ru

The matrix (4) and the shut­ter are behind the mir­ror, and the light does not fall on them. When the pho­tog­ra­ph­er press­es the shut­ter, in a reflex cam­era, the mir­ror first folds up, mak­ing way for the light, and then the shut­ter opens and the light hits the matrix.

Since the light goes through the lens, we see the same thing that the matrix will see. If the cam­era is too far out of focus, the pic­ture in the viewfind­er will be blur­ry. If a fil­ter is installed on the lens, you see what effect it gives.

Look­ing into the viewfind­er of the SLR, we will see some­thing like this pic­ture. In the cen­ter, the focus area and the aut­o­fo­cus sen­sors avail­able for selec­tion are vis­i­ble, the active sen­sor is high­light­ed, the rest are usu­al­ly not vis­i­ble. At the bot­tom is a line with shoot­ing para­me­ters. At a min­i­mum, these are shut­ter speed, aper­ture, ISO val­ue and expo­sure com­pen­sa­tion. In more advanced cam­eras, you can see the shoot­ing mode (PASM), meter­ing mode, the type of file saved (RAW or Jpeg) and the num­ber of pho­tos that can be tak­en before the mem­o­ry card is full.

The green cir­cle in the low­er left cor­ner lights up if the cam­era has suc­cess­ful­ly focused / Pho­to: colourbox.com

A grid can be brought into the field of view to facil­i­tate fram­ing, and in some old­er DSLRs, a lev­el show­ing the cam­er­a’s devi­a­tion from the hor­i­zon­tal and ver­ti­cal.

The size of the reflex viewfind­er direct­ly depends on the size of the cam­era (and the matrix in it). In a large full-frame DSLR, the viewfind­er will be large and bright, but in a small cropped cam­era it will be notice­ably small­er.

The dis­ad­van­tages of opti­cal viewfind­ers include:

• for a per­son who is used to see­ing a fin­ished pic­ture on the screen of a smart­phone or com­pact cam­era, a reflex viewfind­er may be unusu­al. Even if you set the cam­era incor­rect­ly and the final pic­ture is under­ex­posed or over­ex­posed, this will not affect the image in the viewfind­er in any way;
• This viewfind­er can­not be used for movie shoot­ing. The mir­ror either directs the light into the eye­piece or blocks it so that the light hits the matrix;
• noise. The clap­ping of the ris­ing and falling mir­ror does not allow you to shoot silent­ly. Shoot­ing speed lim­it. Before tak­ing each shot, a cam­era with a reflex viewfind­er must raise the mir­ror, and then low­er it into place. As a result, DSLRs reach speeds of 12–14 frames per sec­ond, while mir­ror­less cam­eras eas­i­ly accel­er­ate to 20–30 frames per sec­ond.

Telescopic viewfinder

These viewfind­ers are most com­mon­ly found on advanced com­pact cam­eras such as Canon’s G‑series. There are also some old film cam­eras.

A tele­scop­ic viewfind­er is a sim­ple design of sev­er­al lens­es that allows you to rough­ly see the bound­aries of the frame.

The front viewfind­er win­dow is at a dis­tance from the lens, so the pic­ture in the viewfind­er and the lens is slight­ly dif­fer­ent / Pho­to: canon.com

It does­n’t have many advan­tages. First­ly, it allows you to build a frame when it is dif­fi­cult to see some­thing on the cam­era screen due to the bright sun. Sec­ond­ly, it does not require pow­er, and if you turn off the screen and use only the viewfind­er, the bat­tery will last longer.

But there are many cons. The viewfind­er is small, as is the image in it. In most cas­es, no addi­tion­al infor­ma­tion is vis­i­ble in the viewfind­er. And if the lens moves for­ward when zoom­ing, it will block the viewfind­er field of view.

Range finder

If your cam­era has a rangefind­er viewfind­er, then either you shoot with your grand­fa­ther’s film FED, or with a mod­ern and very expen­sive Leica dig­i­tal cam­era.

To date, Leica pro­duces the major­i­ty of dig­i­tal rangefind­ers / Pho­to: leica-camera.com

The pic­ture in such a viewfind­er will not show you what the cam­era sees. By attach­ing a polar­iz­ing fil­ter to your cam­era, you won’t see any change in the viewfind­er. And even if you for­got to remove the lens cap, you will only know about it when you see the fin­ished pic­ture.

In the field of view of the viewfind­er, frames are vis­i­ble — from them you can rough­ly guess what the cam­era sees. When you install a native lens, the frame cor­re­spond­ing to its focal length is auto­mat­i­cal­ly high­light­ed. As you can see from the pho­to, for a lens with a focal length of 75 mm or more, this frame is quite small, and it is dif­fi­cult to work with tele­pho­to lens­es on a cam­era with such a viewfind­er.

Fram­ing frames for lens­es with dif­fer­ent focal lengths in the viewfind­er of the rangefind­er cam­era Leica M9 / Pho­to: leica-camera.com

An elec­tron­ic viewfind­er looks exact­ly like a reflex viewfind­er — a win­dow through which the pho­tog­ra­ph­er sees the frame. In fact, this is a small screen plus eye­piece lens­es. This means that you can dis­play exact­ly the same infor­ma­tion on it as on the main screen of the cam­era. Such viewfind­ers are used in many mir­ror­less and some advanced com­pact cam­eras.

Elec­tron­ic viewfind­er cam­era Sony / Pho­to: nikonland.eu

The main advan­tages of the elec­tron­ic viewfind­er include the fact that the pic­ture in such a viewfind­er is imme­di­ate­ly dis­played tak­ing into account all the cam­era set­tings. And imme­di­ate­ly shows how the fin­ished pho­to will look like. We changed the white bal­ance or expo­sure — and these changes imme­di­ate­ly became vis­i­ble. This means that even an inex­pe­ri­enced pho­tog­ra­ph­er will eas­i­ly get a cor­rect­ly exposed frame with beau­ti­ful col­ors and make few­er mis­takes.

In addi­tion, a grid can be dis­played in the elec­tron­ic viewfind­er to facil­i­tate fram­ing, lev­el, and a his­togram can be dis­played. It will make life eas­i­er for those who use man­u­al focus when shoot­ing video or like to shoot with old man­u­al lens­es — the includ­ed focus peak­ing will high­light sharp areas.

Through such a viewfind­er, you can shoot video, view the footage, and in some cam­eras even work with the menu.

Since the design of the elec­tron­ic viewfind­er does not require a bulky sys­tem of mir­rors and prisms, it can be made inclined or even remov­able.

The Olym­pus VF‑4 viewfind­er can be attached to the cam­era when you need it, and then removed, mak­ing the mir­ror­less more com­pact / Pho­to: dpreview.com

Mir­ror­less cam­eras have an opti­cal viewfind­er emu­la­tion mode. This is use­ful when you are work­ing with pulsed light. For exam­ple, if you are shoot­ing in a pho­to stu­dio, the image in the elec­tron­ic viewfind­er will prob­a­bly be too dark, since the right amount of light will appear only at the moment the stu­dio flash­es are fired. When you turn on the emu­la­tion mode, the expo­sure set­tings no longer affect the pic­ture, and you will see the scene in the viewfind­er close to how it is seen by the naked eye.

The elec­tron­ic viewfind­er also has its down­sides. First, the elec­tron­ic viewfind­er is based on a screen made up of indi­vid­ual pix­els. And when elec­tron­ic viewfind­ers first appeared, there were few of these pix­els, and they were quite large. And look­ing into such a viewfind­er with a res­o­lu­tion of 0.3 megapix­els (640x480 px), the pho­tog­ra­ph­er saw a mosa­ic of pix­els instead of a smooth image. It was real­ly incon­ve­nient to use such a viewfind­er.

But mod­ern cam­eras have a much high­er viewfind­er res­o­lu­tion (for exam­ple, not the newest and quite pop­u­lar Sony A7 III — 2.3 MP, Lumix S1 — 5.7 MP, Nikon Z 7 — 3.7 MP, Fuji­film X‑T4 — 3 .7 megapix­els, while the lat­est Sony A1 has as much as 9.44 megapix­els). In cam­eras of the lat­est gen­er­a­tions, the pic­ture in the viewfind­er is clear and beau­ti­ful, and indi­vid­ual pix­els are not vis­i­ble.

The next draw­back is the viewfind­er lag, the image in it is a frac­tion of a sec­ond behind what is hap­pen­ing. With the lat­est cam­eras, this delay is very small and almost imper­cep­ti­ble, but still not zero.

In top mod­ern mir­ror­less cam­eras, the viewfind­er lag is almost imper­cep­ti­ble and allows you to shoot even very fast sports / Pho­to: nikonusa.com

And the last minus, which is the most dif­fi­cult to get rid of, is con­stant pow­er con­sump­tion. In order for a pic­ture to be dis­played in the viewfind­er, the cam­era matrix, proces­sor and viewfind­er screen must work. All this requires ener­gy (and the high­er the res­o­lu­tion of the viewfind­er, the more). There­fore, to con­serve bat­tery, mir­ror­less cam­eras should be turned off when not in use.

Conclusion

The viewfind­er is part of the design of the cam­era. What kind of viewfind­er you have deter­mines the type of cam­era. Most often, opti­cal viewfind­ers can be found in DSLRs and rangefind­ers, and elec­tron­ic ones in mir­ror­less and super­zooms. There is an excep­tion — Sony had a line of DSLRs with a translu­cent mir­ror. For exam­ple, Sony A99 Mark II.

In fact, ask­ing which viewfind­er you are com­fort­able using can tell you which type of cam­era is best for you. If you want to imme­di­ate­ly see the pic­ture the way the fin­ished pic­ture will be, then your option is mir­ror­less. If you do not trust the screen and want to look at the pic­ture through mir­rors, then your option is a DSLR.