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How to Check a Used Camera You’re Buying in Person


This arti­cle com­bines the scripts from the two videos above into a sin­gle resource that shows you what to check when buy­ing a used DSLR or mir­ror­less cam­era on Face­book Mar­ket­place or Craigslist.

Buy­ing a used DSLR or mir­ror­less cam­era is a great way to expand your kit on a bud­get, and the best val­ue is typ­i­cal­ly found on Face­book Mar­ket­place, Craigslist, and sim­i­lar sites. How­ev­er, a down­side of buy­ing a used cam­era direct­ly from the own­er is that you’re giv­ing up the peace of mind offered by store refunds and man­u­fac­tur­er war­ranties in exchange for a low­er price. 

Since these deals involve cam­eras that are “final sale” and “as-is”  — mean­ing, there’s no recourse if you find fault in them lat­er — it’s essen­tial to con­firm the camera’s con­di­tion. Here’s the ulti­mate check­list of what to look for when buy­ing a used DSLR or mir­ror­less cam­era in per­son.

Research whether this model suffers from common issues.

Cam­eras can have quirks or man­u­fac­tur­ing defects that are com­mon to spe­cif­ic mod­els. Do a web search to see if the mod­el you’re inter­est­ed in suf­fers from com­mon issues and check for them dur­ing the inspec­tion.

Ask the seller to update the firmware and reset the camera to factory defaults. 

The soft­ware pow­er­ing your cam­era is called firmware. Like all soft­ware, firmware can have bugs. Cam­era mak­ers some­times release firmware updates that fix bugs and add or expand soft­ware-based fea­tures. Firmware bugs can eas­i­ly be con­fused for phys­i­cal faults or defects, and so can the pre­vi­ous own­ers’ cus­tomiza­tions. It’d be a shame to pass up an oth­er­wise excel­lent cam­era because a bug fix wasn’t installed or a non-stan­dard but­ton assign­ment that wasn’t reset. You can avoid these pit­falls by ask­ing the sell­er to update the firmware and reset the cam­era to defaults before you meet.

Don’t allow the seller to pressure you into a quick inspection.

If the sell­er claims they’re in a rush and have some­where else to be, there’s a good chance they’re hid­ing some­thing and hop­ing that a cur­so­ry inspec­tion will miss it. Always take as much time as nec­es­sary to con­duct your assess­ment or ter­mi­nate the deal. Don’t suc­cumb to pres­sure; you don’t owe the sell­er any favours.

Check the battery and its compartment for corrosion and damage.

Open the bat­tery com­part­ment and remove the bat­tery. On most mod­ern cam­eras, the bat­tery is spring-eject­ed upon release. A dam­aged or defec­tive lithi­um bat­tery can some­times swell to a point where the spring can­not push it far enough to pull out. This is a sign the bat­tery will need replac­ing.

Once the bat­tery is removed, use your phone’s LED to inspect the elec­tron­ic con­tacts inside the bat­tery com­part­ment for signs of cor­ro­sion or oxi­da­tion. I’d con­sid­er any dam­age a deal­break­er because it can cause shorts, pow­er loss, and so forth. 

Power on the camera. 

Place the bat­tery into the cam­era, ensure that it fits well and secures into place, close the com­part­ment door, and turn the camera’s pow­er on.

Check the memory card slot(s) and confirm they work.

With the aid of your phone’s LED, check the slots for dust and dam­age. This is a crit­i­cal check on cam­eras that use Com­pact Flash (CF) cards since they don’t phys­i­cal­ly pre­vent acci­den­tal side­ways inser­tion, which could lead to bent pins. Always bring your own mem­o­ry cards to check for com­pat­i­bil­i­ty. Make sure they lock into place, and the cam­era can read and write to them—you can snap a few pho­tos to con­firm.

Check the electronic terminals and flash hot shoe.

Mod­ern cam­eras have a vari­ety of elec­tron­ic ter­mi­nals such as HDMI, USB, and audio ports. Because there are so many, it’s not always prac­ti­cal to check every port with­out the appro­pri­ate cables and con­nect­ing device on hand. Instead, per­form a visu­al inspec­tion of each ter­mi­nal for dust, debris, and bent or bro­ken pins. And when you’re buy­ing a cam­era for a pur­pose that involves a spe­cif­ic ter­mi­nal, def­i­nite­ly bring some­thing to ensure it’s in work­ing order. 

Also, make sure to check the camera’s exter­nal flash hot shoe mount for cor­ro­sion. Some mounts may be cov­ered by plas­tic tabs, so feel free to remove them. Bet­ter yet, bring any hot shoe-mount­ed flash and test it with the cam­era. While most flash units are designed to work with a spe­cif­ic cam­era sys­tem, vir­tu­al­ly every con­tem­po­rary cam­era can fire a hot shoe flash when tak­ing a pho­to. 

Check the condition of the doors and rubber flaps.

Pay atten­tion to the con­di­tion of the plas­tic doors and rub­ber flaps that pro­tect the ter­mi­nals. Do they close flush with the cam­era body? Are the anchors attach­ing the rub­ber flaps in good shape? For cam­eras with “weath­er resis­tance,” check the con­di­tion of the rub­ber or foam seals on all doors and flaps.  

Check the camera’s lens mount and electronic contact pins.

A lens is attached to a cam­era using the mount, which pro­vides a secure attach­ment point and ensures the lens and cam­era are cor­rect­ly aligned. All cam­era lens mounts are metal­lic and take deter­mi­na­tion to dam­age.

The elec­tron­ic con­tact pins found just beyond the inte­ri­or edge of the lens mount facil­i­tate com­mu­ni­ca­tion with lens­es. Ensure that the con­tact pins are clean, not bent, and don’t exhib­it signs of cor­ro­sion. Remem­ber to hold the cam­era face-down­ward while per­form­ing these checks to min­i­mize dust enter­ing the cav­i­ty. 

The eas­i­est way to con­firm is by mount­ing your own com­pat­i­ble lens, ensur­ing it secures into place with an audi­ble click. Although a tiny amount of rota­tion­al give is accept­able, the lens should fit tight­ly, and there shouldn’t be any tilt­ing or sag­ging. 

Con­firm that the cam­era rec­og­nizes the lens by engag­ing the aut­o­fo­cus and adjust­ing the aper­ture. Take sev­er­al pho­tos while adjust­ing the aper­ture and focus loca­tion between each shot. Then, exam­ine the pic­tures to con­firm the changes.

[DSLR] Check the mirror box components.

When exam­in­ing a DSLR, it’s cru­cial to check the pri­ma­ry com­po­nents found in the mir­ror box. These include the mir­ror itself and the ground glass focus­ing screen onto which light from the mir­ror reflects to form the image seen in the viewfind­er. The focus­ing screen is locat­ed at the roof of the mir­ror box. They should be free from water marks, dirt, and scratch­es. Hold the cam­era fac­ing down when per­form­ing this check to min­i­mize dust con­t­a­m­i­na­tion.

Inspect the image sensor for damage and dust.

There are two ways to check the image sen­sor. You can per­form a direct visu­al inspec­tion of the sen­sor itself, or you can check the pho­tos it takes. I rec­om­mend doing both.

Per­form­ing a visu­al inspec­tion is sim­plest on a mir­ror­less cam­era. Remove the lens or body cap from the cam­era, and look at the sen­sor inside. The eas­i­est way to check a DSLR’s image sen­sor is by select­ing a long expo­sure time in Shut­ter Pri­or­i­ty mode—something like 30 sec­onds or longer—and “tak­ing a pic­ture” with the lens off. With the cam­era held face-down, exam­ine the sen­sor with the aid of your phone’s LED. You should see a smooth iri­des­cent sur­face that’s free from scratch­es and dam­age. Don’t be alarmed or dis­ap­point­ed if you see dust, as it’s com­plete­ly nor­mal and rel­a­tive­ly easy to clean. 

The sec­ond method of check­ing an image sen­sor is by tak­ing a pho­to. To do this, select ƒ/16 or high­er in Aper­ture Pri­or­i­ty mode, then point the cam­era at a bright and fea­ture­less sub­ject (such as the sky or a white wall) and take a shot. Blur­ry dots and specks are dust or grit, and blur­ry squig­gles are fibres; blur­ry lines, espe­cial­ly longer and straighter ones, are like­ly scratch­es. 

Does the shutter work?

The shut­ter is a pre­ci­sion mech­a­nism that’s cru­cial to the func­tion­al­i­ty of a cam­era. The esti­mat­ed dura­bil­i­ty of a shut­ter is described by cam­era mak­ers as shut­ter life­time and expressed in shut­ter actu­a­tions, which is the num­ber of times a shut­ter has fired. Gen­er­al­ly, cam­eras with few­er shut­ter actu­a­tions car­ry a pre­mi­um over those with more. In this respect, they’re like the odome­ters on cars. There are sev­er­al ways to check the num­ber of cam­era shut­ter actu­a­tions. Still, they vary from brand to brand, so I rec­om­mend doing a web search about the mod­el you’re con­sid­er­ing. Since this only mat­ters if the shut­ter works, it’s essen­tial to do sev­er­al checks.

Check whether chang­ing the shut­ter speed actu­al­ly changes the expo­sure. In Shut­ter Pri­or­i­ty mode, take sev­er­al pho­tos across a range of shut­ter speeds, from one sec­ond to the camera’s fastest, which is typ­i­cal­ly 1/4000s or 1/8000s. Review the images to ensure that they’re even­ly illu­mi­nat­ed from top to bot­tom. The shut­ter is begin­ning to mal­func­tion if the top or bot­tom of the frame starts to grow pro­gres­sive­ly dark­er at faster speeds.  

When tak­ing these pho­tos, pay atten­tion to whether there’s a notice­able delay between depress­ing the shut­ter but­ton and the shut­ter fir­ing. Some delays are caused by the aut­o­fo­cus­ing sys­tem, so set the lens to man­u­al focus first.

If the cam­era is capa­ble of con­tin­u­ous or burst mode, test to make sure it works. Set a rea­son­ably fast shut­ter speed, point the cam­era at a sta­t­ic scene, and take a burst of pho­tos. The pho­tos should all be con­sis­tent­ly exposed. 

Does the autofocus work, and is it correctly aligned?

This advice comes from per­son­al expe­ri­ence. I once dropped my DSLR, and the impact cre­at­ed a slight mis­align­ment between the aut­o­fo­cus sys­tem and the focus points dis­played in the viewfind­er. Essen­tial­ly, when I want­ed to use a sin­gle focus point on a sub­ject, the cam­era would focus the lens on the area halfway to the left adja­cent focus point. It was a huge pain in the butt and cost­ly to repair.

A mir­ror­less camera’s aut­o­fo­cus sys­tem is built into the image sen­sor. If the sen­sor works, the aut­o­fo­cus sys­tem can take read­ings. You want to test that it accu­rate­ly com­mu­ni­cates focus read­ings to the lens.

To test the aut­o­fo­cus sys­tem on either type of cam­era, com­pose a pho­to of a small, well-defined sub­ject that stands out against the back­ground. Using a sin­gle focus­ing point, aut­o­fo­cus on the left edge of the sub­ject and take a pho­to. Take a sec­ond shot focus­ing on the subject’s right edge. You can repeat these steps on the top and bot­tom edges to be extra thor­ough. Just make sure to man­u­al­ly defo­cus the lens between every shot. After you’re done, review the pho­tos on the screen to con­firm whether the cam­era focused on the intend­ed tar­get.

Check that the shooting mode dial works correctly.

Your choice of shoot­ing mode deter­mines which cam­era set­tings and con­trols you can access. Except for sev­er­al retro-inspired and pro-lev­el mod­els, most cam­eras have a rotat­ing dial for select­ing shoot­ing modes. You want to con­firm that the phys­i­cal dial and its elec­tron­ic con­nec­tions are work­ing and cor­rect­ly aligned with the indi­cat­ed mode. In prac­tice, this means select­ing M puts the cam­era into Man­u­al Mode, select­ing A (or Av) puts the cam­era into Aper­ture Pri­or­i­ty Mode, and so on. Ensure the detents are firm, and if the dial has a lock­ing func­tion, that it works.

Does the main screen work?

Check­ing whether the rear screen works is straight­for­ward: switch on the cam­era, push the Menu or Info but­tons, and the screen should acti­vate. To check for dead pix­els, take one com­plete­ly white (over­ex­posed) pho­to and review it for black dots. To check for hot pix­els, take a com­plete­ly black (under­ex­posed) photo—keeping the lens cap on helps—and review it for pix­els that won’t turn off. 

If the mir­ror­less cam­era you’re con­sid­er­ing has an Elec­tron­ic Viewfind­er, check the frames you just cap­tured in it as well, as EVFs can also have defec­tive pix­els. 

If the LCD is a touch­screen, give it some pokes, swipes, and pinch-to-zooms to ensure accu­rate touch sen­si­tiv­i­ty. 

If the cam­era you’re exam­in­ing fea­tures a mul­ti­di­rec­tion­al screen, check the con­di­tion of its joints by mov­ing it around and con­firm­ing that it stays in place.

If the DSLR has Live View or movie mode, make sure they work.

Many new DSLRs have a fea­ture known as Live View, which lets them work like mir­ror­less cam­eras by dis­play­ing a live image on the rear screen. They do this by rais­ing the mir­ror and open­ing the shut­ter so the light from the lens can fall direct­ly onto the image sen­sor for as long as Live View is active. It’s typ­i­cal­ly acti­vat­ed by a ded­i­cat­ed but­ton. 

Acti­vat­ing video mode on a DSLR will also throw it into Live View, show­ing the view on the rear LCD. Regard­less of your cam­era type, you can test video mode by record­ing a video and review­ing the result. 

Do all the physical controls work?

This is about check­ing the phys­i­cal integri­ty of the con­trols them­selves, not the under­ly­ing fea­tures asso­ci­at­ed with them. If rotat­ing a dial, push­ing a but­ton, or mov­ing a switch caus­es the cam­era to respond, it’s rea­son­able to con­clude it works. Just make sure the but­tons have ade­quate resis­tance and the dials main­tain their detents. 

The pit­fall in this assump­tion is reas­signed cus­tom func­tion but­tons. To ensure that you don’t con­fuse the seller’s cus­tomiza­tion for mal­func­tion­ing but­tons, remem­ber to ask them to reset the cam­era to fac­to­ry defaults before you meet.

Does the built-in flash work?

As a rule of thumb, an opened pop-up flash always fires when tak­ing a pic­ture. The only excep­tion is the “No Flash” Auto shoot­ing mode on some entry-lev­el cam­eras. The sim­plest way to fire a pop-up flash is by rais­ing it, set­ting the cam­era into Man­u­al shoot­ing mode, and tak­ing a pic­ture.  

And while I’m on the sub­ject of flash, some advanced and pro­fes­sion­al cam­era mod­els fea­ture IR or wire­less trig­ger­ing of remote flash heads. If this func­tion is vital to you, con­sid­er this your reminder to test it.

Check the tripod mount threading. 

The hum­ble tri­pod mount is found on the bot­tom of vir­tu­al­ly every dig­i­tal cam­era. How­ev­er, it’s often over­looked dur­ing inspec­tions because of its ubiq­ui­ty and rel­a­tive stur­di­ness. You can per­form a quick visu­al inspec­tion of the tri­pod mount to con­firm no cross-thread­ing dam­age. Still, I rec­om­mend bring­ing a tri­pod mount­ing plate or 1/4” ‑20 screw for phys­i­cal con­fir­ma­tion.

What is the condition of the strap connectors?

A sim­i­lar­ly over­looked phys­i­cal fea­ture of most cam­eras is the strap con­nec­tor. I should empha­size that I’m not refer­ring to the strap itself or the loose­ly attached strap rings or tri­an­gles. The strap con­nec­tors are the met­al eye­lets per­ma­nent­ly attached to the sides of the cam­era body. These unre­mark­able parts are indis­pens­able for your cam­er­a’s con­ve­nient and safe use. Make sure they’re not bent, cracked, or detach­ing.  

[DSLR] What is the condition of the viewfinder?

In addi­tion to check­ing it for dust or lint, the viewfind­er assem­bly also con­tains light mea­sur­ing sen­sors that deter­mine auto expo­sure and assist in man­u­al expo­sure. To check whether the light meter is work­ing, select any auto shoot­ing modes and point the cam­era at dif­fer­ent parts of the scene. You should see a change in the shut­ter speed and aper­ture val­ues as your view sweeps across the scene, which indi­cates that the meter is work­ing.

[Mirrorless] What is the condition of the electronic viewfinder?

You’ve prob­a­bly already con­firmed that the inter­nal dis­play works when tak­ing test shots and check­ing for defec­tive pix­els. Now it’s time for a more thor­ough check for inter­nal dust, mois­ture, and scratch­es on the eye-fac­ing lens.

Addi­tion­al­ly, make sure the IR prox­im­i­ty sen­sor acti­vates the EVF when you move your eye towards it, and turns it off when you low­er the cam­era.

Does the viewfinder’s diopter control work?

The diopter adjuster allows you to set the viewfind­er to match your eye­sight. It’s typ­i­cal­ly a wheel or switch locat­ed some­where near the viewfind­er. To check that it works, or whether it’s strong enough to cor­rect for your eye­sight, look through the find­er with your unaid­ed eye and adjust the diopter con­trol until the viewfind­er indi­ca­tors come into sharp relief. 

Alter­na­tive­ly, on a mir­ror­less cam­era, you can adjust the diopter while look­ing nav­i­gat­ing the camera’s menu or review­ing an exist­ing pho­to with­in the EVF.

Is the viewfinder eyecup included and in good condition?

Check whether the rub­ber eye­cup is includ­ed and inspect its con­di­tion. It’s typ­i­cal­ly made from soft rub­ber that can wear with time or start to sep­a­rate from the under­ly­ing plas­tic frame. Your goal is to ensure that the cam­era you’re inspect­ing fits the adver­tised descrip­tion. If the cam­era wasn’t described as “like new,” don’t nit­pick the eye­cup since it’s easy to replace.

Is the camera sold with all accessories? 

Most cam­era man­u­als list all the acces­sories includ­ed in the box. Go over the list to ensure you’re get­ting every­thing adver­tised by the sell­er. And if the bat­tery charg­er is includ­ed, ensure that it works.  


Now you should know what to check for when buy­ing a used DSLR or mir­ror­less cam­era in per­son. If you have requests for top­ics, let me know in the com­ments, and I’ll con­sid­er them for future arti­cles.

Checklist for buying a used camera in person:

  • Research whether this mod­el suf­fers from com­mon issues.
  • Ask the sell­er to update the firmware and reset the cam­era to fac­to­ry defaults.
  • Don’t allow the sell­er to pres­sure you into a quick inspec­tion.
  • Check the bat­tery and its com­part­ment for cor­ro­sion and dam­age.
    • What is the battery’s con­di­tion?
  • Pow­er on the cam­era.
  • Check the mem­o­ry card slot(s) and con­firm they work.
    • What is the con­di­tion of the slot(s)?
    • Can cam­era read and write to your cards?
  • Check the elec­tron­ic ter­mi­nals and flash hot shoe.
    • Bring acces­sories to test vital ports.
  • Check the con­di­tion of the doors and rub­ber flaps.
    • What is the con­di­tion of weath­er seal­ing (if any)?
  • Check the camera’s lens mount and elec­tron­ic con­tact pins.
  • [DSLR] Check the mir­ror box com­po­nents.
    • Mir­ror?
    • Ground glass screen?
  • Inspect the image sen­sor for dam­age and dust.
    • Visu­al inspec­tion.
    • Pic­ture inspec­tion.
  • Does the shut­ter work?
    • What is the shut­ter count?
    • Con­firm fast and slow shut­ter speeds.
    • Con­firm burst mode (if any) pro­duces con­sis­tent expo­sures.
  • Does the aut­o­fo­cus work, and is it cor­rect­ly aligned?
    • Are the viewfind­er focus­ing points aligned cor­rect­ly?
    • Does the cam­era focus the lens?
  • Check that the shoot­ing mode dial works cor­rect­ly.
  • Does the main screen work?
    • Does it acti­vate?
    • Does it have defec­tive pix­els?
    • [Mir­ror­less] Does EVF have defec­tive pix­els?
    • Does touch sen­si­tiv­i­ty work?
    • Does mul­ti­di­rec­tion­al screen move and stay in place?
  • [DSLR] If the cam­era has Live View or movie mode, make sure they work.
  • Do all the phys­i­cal con­trols work?
  • Does the built-in flash work?
    • Does the IR or wire­less trig­ger­ing func­tion work?
  • Check the tri­pod mount thread­ing.
  • What is the con­di­tion of the strap con­nec­tors?
  • [DSLR] What is the con­di­tion of the viewfind­er?
    • Does the expo­sure meter func­tion?
  • [Mir­ror­less] What is the con­di­tion of the elec­tron­ic viewfind­er?
    • Does the prox­im­i­ty sen­sor work?
  • Does the viewfinder’s diopter con­trol work?
  • Is the viewfind­er eye­cup includ­ed and in good con­di­tion?
  • Is the cam­era sold with all acces­sories?

How to Choose Your Next Portrait Lens—Part 1

What is a photographic portrait?

In pho­tog­ra­phy, a por­trait is loose­ly defined as a rep­re­sen­ta­tion of a per­son whose face and expres­sion form an inte­gral part of the image. While the pre­dom­i­nant sub­jects of por­traits are peo­ple, they may also fea­ture ani­mals, such as pets. Per­son­al­ly, I’ve tak­en many por­traits of my pets.

Many begin­ner pho­tog­ra­phers incor­rect­ly assume that por­traits are lim­it­ed to scales that depict a per­son from just above their head to their chest or shoul­ders. Although the visu­al scale of a por­trait is loose­ly defined, we can set sev­er­al basic lim­its. For exam­ple, although the eyes are impor­tant for facial iden­ti­ty and expres­sion, they occu­py a rel­a­tive­ly small part of the face. There­fore, an extreme close­up of one eye is not a por­trait. Con­verse­ly, an extreme long-shot—being a pho­to where some com­bi­na­tion of great dis­tance or angle-of-view ren­ders the sub­ject in small relief against their surroundings—is also not a por­trait because the face and expres­sion are lost in their sur­round­ings. Any scale of rep­re­sen­ta­tion that lies between extreme close­ups and extreme long-shots can be a por­trait and lends cre­ative flex­i­bil­i­ty to your expres­sion. 

What makes a lens suitable for portraits?

What is a por­trait lens? You can cap­ture a por­trait with any pho­to­graph­ic lens. How­ev­er, this doesn’t mean every lens is a por­trait lens. Tra­di­tion­al­ly, por­trait lens­es have sev­er­al prop­er­ties that make them more suit­able for that role than oth­er lens­es. 

Large aperture

One of these prop­er­ties is a rel­a­tive­ly fast (that is, large) max­i­mum aper­ture. This would mean an aper­ture of ƒ/2.8 or greater for a zoom lens and an aper­ture of ƒ/2.0 or greater for a fixed-focal-length lens. (And keep in mind: low­er f‑numbers rep­re­sent larg­er aper­tures.)

The aper­ture serves two pur­pos­es. First, it affects expo­sure by lim­it­ing how much light can pass through the lens. And sec­ond, it affects the depth of field, which describes the degree to which areas that lie out­side the plane of focus appear accept­ably sharp.  

Pho­tog­ra­phers exploit the depth of field to achieve effects such as deep or shal­low focus. We use a large depth of field to attain accept­able sharp­ness in the fore‑, middle‑, and back­ground of the pic­ture. Con­verse­ly, selec­tive focus pho­tog­ra­phy fea­tures a nar­row or small depth of field char­ac­ter­ized by a sharply focused sub­ject and a blur­ry back­ground and fore­ground. 

Lens­es with large max­i­mum apertures—represented by small f‑numbers and called “fast” lenses—give por­trait pho­tog­ra­phers the option to cap­ture pho­tos with a shal­low­er depth of field than slow­er lens­es can obtain. Por­trait pho­tog­ra­phers often use a shal­low depth of field because it cre­ates a strik­ing visu­al sep­a­ra­tion between the sub­ject and their sur­round­ings. It’s ben­e­fi­cial in can­did sit­u­a­tions, which dif­fer from stu­dios or oth­er con­trolled loca­tions because the back­ground is either impos­si­ble or imprac­ti­cal to change to your lik­ing. Your only option for min­i­miz­ing back­ground dis­trac­tions becomes ren­der­ing them out of focus.

Superior image quality and portrait lenses

Anoth­er desir­able prop­er­ty of por­trait lens­es is high image qual­i­ty. This is a fair­ly com­plex sub­ject that war­rants sev­er­al ded­i­cat­ed videos, but I’ll briefly touch upon two impor­tant com­po­nents for por­trai­ture: good sharp­ness and pleas­ing bokeh. 

Portrait lenses and sharpness

Sharp­ness describes the abil­i­ty of a lens to resolve fine detail of a sub­ject that’s in focus. In prac­tice, it’s char­ac­ter­ized by the fine details and edges in the scene being ren­dered as fine details and edges in the pho­to­graph. When every­thing is focused, a sharp lens ren­ders dis­tinct details across the frame. In con­trast, a less­er lens may pro­duce images with a loss of sharp­ness towards the cor­ners, where details may appear smeared, blurred, or split into their con­stituent colours, as if by a prism. Such loss of sharp­ness is caused by the pres­ence of opti­cal aber­ra­tions, to which no lens is immune.

Most mod­ern lens­es can eas­i­ly pro­duce sharp pho­tos that show crisp edges and defined details across the frame when their aper­tures are set to the range of ƒ/5.6–11. How­ev­er, por­trait pho­tog­ra­phers often take pho­tos close to their lens’s largest aper­ture to achieve focus sep­a­ra­tion between the sub­ject and back­ground. This presents a chal­lenge for lens mak­ers because the aperture’s size strong­ly impacts image sharp­ness. Opti­cal aber­ra­tions are most pro­nounced when a lens is set to its largest aper­ture, and aber­ra­tions decrease as the aper­ture is stopped down. 

While no lens is immune to sharp­ness-degrad­ing aber­ra­tions, and every pho­to­graph­ic lens has more aber­ra­tions at larg­er aper­tures than small­er aper­tures, smart engi­neer­ing, supe­ri­or glass, and pre­ci­sion assem­bly of your lens will have a mea­sur­able impact on its over­all sharp­ness, includ­ing at its largest aper­ture set­ting. A high-qual­i­ty lens that pro­duces sharp images, even at large aper­tures, allows you to achieve a shal­low depth of field and pre­cise­ly ren­der the sub­tle details of your subject’s face, espe­cial­ly in the eyes and eye­lash­es.

Portrait lenses and bokeh

Anoth­er impor­tant trait of a good por­trait lens is how well it can ren­der blur­ry parts. Pho­tog­ra­phers use the term “bokeh” to describe the visu­al and aes­thet­ic char­ac­ter­is­tics of the out-of-focus areas in pho­tos. Begin­ner pho­tog­ra­phers are often sur­prised to dis­cov­er that all lens­es aren’t cre­at­ed equal in terms of the objec­tive and sub­jec­tive attrib­ut­es of their defo­cus blur­ring.

Bokeh can exhib­it var­i­ous objec­tive qual­i­ties that are influ­enced by the opti­cal design of a lens. Bokeh can be round, oval, or polygonal—in which case it’s tak­ing on the shape of the lens’s aper­ture diaphragm. Swirly bokeh appears to swirl or rotate about the opti­cal cen­tre of a lens. Cata­diop­tric lenses—commonly called mir­ror lenses—create very dis­tinct donut- or ring-shaped bokeh, which are espe­cial­ly vis­i­ble in out-of-focus high­lights. Lens­es with aspher­i­cal glass ele­ments ren­der bokeh that looks like the con­cen­tric rings of an onion.  

Bokeh can also fea­ture var­i­ous sub­jec­tive qual­i­ties that pho­tog­ra­phers often describe using words such as “smooth” and “creamy” when describ­ing pleas­ing qual­i­ties or “ner­vous” and “busy” to describe unde­sir­able qual­i­ties. A hideous and dis­trac­tive type of defo­cus blur­ring is called “Nisen” or dou­ble-line bokeh.

Apply­ing this infor­ma­tion towards your next por­trait lens pur­chase takes a lit­tle research. Every pho­to retail­er makes it triv­ial to fil­ter their lens inven­to­ry by max­i­mum aper­ture, and even if they didn’t, that num­ber forms part of the name of vir­tu­al­ly every lens you can buy. Search­ing for a par­tic­u­lar lens’s image qual­i­ty takes a lit­tle bit more effort, and you’ll have to refer to the wealth of lens and cam­era review web­sites vying for your eye­balls. My per­son­al favourite site for con­cise lens reviews is OpticalLimits.com. 

Choos­ing an appro­pri­ate focal length for your next por­trait lens is where mat­ters become incred­i­bly sub­jec­tive, and I’ll be cov­er­ing that in the sec­ond part of this two-part series.