10 essential tips for picking the right monitor for a digital picture frame

By January 6, 2019 May 11, 2019 DIY Instructions, Hardware

The selec­tion of a suit­able dis­play for your Rasp­berry Pi dig­i­tal pic­ture frame project is prob­a­bly the most impor­tant com­po­nent deci­sion that you will make.

If you want to cre­ate a real­ly impres­sive dig­i­tal pic­ture frame, here are some use­ful tips for you.

In short, get a slim 24 inch­es mat­te IPS mon­i­tor with a res­o­lu­tion of 1920 x 1200 (aspect ratio of 16:10) and down­ward fac­ing HDMI and pow­er input.

Let's go into a bit more detail.

Display size and resolution: When size really matters

There are plen­ty of 15 or 17 inch­es (and small­er) dig­i­tal pho­to frames on the mar­ket to buy. How­ev­er, their size, image qual­i­ty, con­trast, and res­o­lu­tion is gen­er­al­ly not enjoy­able for very long, and you or your fam­i­ly will lose inter­est quick­ly.

What you want is some­thing that will bring up mem­o­ries, will cre­ate con­ver­sa­tion­al top­ics and lets you dream. You want your dig­i­tal pic­ture frame to be a high­light of your liv­ing room. This is why the size mat­ters a lot.

Look at how aver­age tele­vi­sion screens sizes have gone from a mere 30 to 75 inch­es in the last twen­ty years (not to men­tion Samsung's "The Wall" tele­vi­sion shown at Las Vegas CES 2019 with 219 inch­es). The baby boomers will remem­ber their first com­put­er screens hav­ing a size of 13 or 15 inch­es.

A large screen pro­vides a much bet­ter visu­al expe­ri­ence to a dig­i­tal pic­ture frame and this is why you shouldn't pick a small one.

So how big can you go?

The Rasp­berry Pi has an HDMI port which allows a max­i­mum res­o­lu­tion of 1920x1200. There are some tweaks to increase it but you will encounter plen­ty of prob­lems with the dis­play soft­ware, so I would rec­om­mend not to go there.

So go with a 24 inch­es mon­i­tor with a 1920 x 1200/1080px res­o­lu­tion. It's ide­al.

If you choose a mon­i­tor larg­er than 24 inch­es and keep the res­o­lu­tion at 1920 x 1200/1080px, the dot pitch size (the dis­tance between pix­els on a dis­play) will increase, and the image qual­i­ty will not be as sharp.

If you plan on using your dig­i­tal pic­ture frame in adver­tis­ing or you need a larg­er screen size and don't care so much about the best pos­si­ble image qual­i­ty, then use the largest qual­i­ty screen you can find that works at 1920 x 1200/1080px res­o­lu­tion. As a guide­line, the clos­er peo­ple can get to a dis­play, the bet­ter the res­o­lu­tion should be.

With today's Rasp­berry Pi's tech­ni­cal archi­tec­ture, a 24 inch­es mon­i­tor is ide­al. Of course you can pick a small­er mon­i­tor depend­ing on your spe­cif­ic appli­ca­tion but for a liv­ing room, 24 inch­es is high­ly rec­om­mend­ed.

As soon as the Rasp­berry Pi con­sor­tium launch­es a tech­ni­cal upgrade which allows for a high­er res­o­lu­tion (dream­ing of 4K), I will update this post. Hav­ing a tack sharp 30 inch­es dis­play and big­ger is some­thing I can't wait to build.

Aspect ratio - why does it have to be so confusing?

Since the 1920s the com­mon­ly used aspect ratio for movies was 4:3 as deter­mined by Thomas Edi­son. They called it "the mag­ic rec­tan­gle" and it was used in movie the­aters and lat­er at home in tele­vi­sion sets.

When in the 1950s the Cin­e­maS­cope tech­nol­o­gy made the wide-screen for­mat pop­u­lar, the aspect ratio of movies was changed for­ev­er to wide-screen, and tele­vi­sion sets lat­er fol­lowed this form fac­tor to a cer­tain degree (wide screens at the movie the­aters are still much wider than most "wide-screen" tele­vi­sion sets).

In pho­tog­ra­phy, the Sin­gle Lens Reflex (SLR) stan­dard for film and slides had a for­mat of 36 x 24 mm, which trans­lat­ed into an aspect ratio of 3:2. This hasn't changed with the arrival of dig­i­tal SLR cam­eras.

But the cheap­er com­pact dig­i­tal cam­eras and their sub­se­quent replace­ment by mobile phones have lead to many dif­fer­ent for­mats.

There are micro four-thirds cam­eras (as the name implies 4:3 aspect ratio), cam­eras that let you choose between dif­fer­ent aspect ratios and mobile phones that are 4:3, 1:1 and many more.

This makes it dif­fi­cult to choose a dis­play. Or not. Because in con­trast to movies, most of the pho­tos are gen­er­al­ly tak­en in either 4:3 or 3:2 for­mat.

Unfor­tu­nate­ly, the man­u­fac­tur­ers of com­put­er dis­plays have fol­lowed the wide-screen trend of tele­vi­sion sets.

Above a screen size of 24 inch­es, you will be hard pressed to find a mon­i­tor that doesn't at least have 16:9 or even a wider aspect ratio. Luck­i­ly, there are still a few 16:10 mon­i­tors in the 24 inch­es size range to be found. But not too many and I won­der for how long.

The wider screen dis­play you choose, the more your images will have to be cropped or have a black frame around.

Nei­ther is ide­al.

I would rec­om­mend that you go with a 1920 x 1200 px mon­i­tor which pro­vides a 16:10 aspect ratio.

Viewing angle

This is also an impor­tant issue as it defines how well you can see what is on the screen from a mul­ti­tude of view­ing direc­tions. The image may become dark­er, gar­bled or show strange col­ors if the view­ing angle is low.

Espe­cial­ly in a liv­ing room or in a pro­fes­sion­al set­ting, you want to have a screen that can be viewed just as well from about any direc­tion. The the­o­ret­i­cal max­i­mum view­ing angle is 180 degrees both hor­i­zon­tal­ly and ver­ti­cal­ly.

The indus­try has made a lot of progress in this area, so that most mod­ern IPS dis­plays allow for view­ing angles greater than 160 degrees hor­i­zon­tal and 140 degrees ver­ti­cal which are excel­lent for any liv­ing room appli­ca­tion.

But it always helps to check!

Contrast - make it look beautiful

The con­trast ratio of a dis­play is indi­cat­ed as "Typ­i­cal" and "Max­i­mum." As with so many tech­ni­cal spec­i­fi­ca­tions here, they tend not to be very con­sumer friend­ly.

Look for the "Con­trast Ratio (Typ.)" which for a good screen is at around 1000:1 (the high­er, the bet­ter).

For­get about the oth­er "Con­trast Ratio ("max­i­mum" or "dynam­ic") which is indi­cat­ed with rather use­less val­ues like 80,000,000:1.

Most com­put­er mon­i­tors man­u­fac­tured in recent years will cor­re­spond to these val­ues.

Glossy versus matte - screen glare or very vivid colors

Do you pre­fer more vivid col­ors (glossy) or a non-reflect­ing screen (mat­te)?

This is a sub­ject of much debate.

Apple has changed all of its com­put­ers to glossy screens because they pro­vide great col­ors. Many of their com­peti­tors have fol­lowed their lead.

But espe­cial­ly in sit­u­a­tions with direct sun­light but also indoor with light sources shin­ing on the dis­play, you will see notice­able reflec­tions which can make a glossy dis­play pret­ty much unus­able in direct sun­light.

Mat­te screens car­ry an anti-glare coat­ing and are there­fore bet­ter at pre­vent­ing reflec­tions. How­ev­er, their ren­der­ing of col­ors is con­sid­ered to be some­what less vivid.

Even­tu­al­ly, it all boils down to your per­son­al pref­er­ences.

My per­son­al expe­ri­ence is that mat­te dig­i­tal pic­ture frame are prefer­able for any liv­ing room sit­u­a­tion. The col­ors are great and not as exag­ger­at­ed as glossy dis­plays. A mat­te dig­i­tal pic­ture frame blends in nice­ly into a social set­ting with­out draw­ing too much atten­tion.

I work with glossy com­put­er dis­plays all day, but for a dig­i­tal pic­ture frame, I would still choose a mat­te screen.

For a dark­er set­ting like in a muse­um with lights com­ing down straight from the ceil­ing and the sun­light com­ing through the frost­ed glass, reflec­tions are less of an issue, and glossy screens will look great.

It's a mat­ter of taste and intend­ed appli­ca­tion area.

HDMI Display Connector - the only one you need

The Rasp­berry Pi comes with an HDMI con­nec­tor so that is what you should be look­ing for on the mon­i­tor side.

There are adapters from DVI to HDMI but this takes up pre­cious real estate behind your mon­i­tor and the wall, so it is prefer­able to avoid it.

Don't use a VGA to HDMI adapter as the image will be ana­log instead of dig­i­tal and may induce flick­er.

What's impor­tant is the direc­tion of the HDMI con­nec­tor. Make sure that you choose one which points down­wards instead of out­wards as the lat­ter will increase the depth of your pic­ture frame.

If that is not pos­si­ble, there are right angle HDMI cables. When you pick one of those, make sure that the direc­tion of the right angle cable is what you need, most like­ly one that goes upward from your HDMI out­put.

Depth of monitor - physical dimensions to make your frame fit nicely

The phys­i­cal depth of the dis­play will deter­mine the dis­tance of your frame from the wall.

Over­all mod­ern IPS dis­plays have got­ten quite slim, but there are still sub­stan­tial dif­fer­ences.

Units with an inte­grat­ed pow­er sup­ply are deep­er by design than those with an exter­nal pow­er adapter. And high-end dis­plays tend to be a bit thick­er than basic types.

Unless you want to make a large rec­tan­gle hole in your wall which may not be extreme­ly pop­u­lar with your sig­nif­i­cant oth­er (spousal guid­ance rec­om­mend­ed), you may want to look at the phys­i­cal dimen­sions of the screen.

You will remove the mon­i­tor stand any­way, so you can deduct this when you com­pare screens. The dis­play itself is only about 0.4 in/1 cm thick, but the pow­er sup­ply and the LCD con­troller often take up anoth­er 0.8-1.2 in/2-3 cm.

Usu­al­ly, the rather bulky pow­er sup­ply is locat­ed in the mid­dle of the dis­play, and you can use the space on the sides to mount your Rasp­berry Pi with its pow­er sup­ply and cables, but that still means that you have a dis­play to wall dis­tance of about 2.7in/7 cm.

So assum­ing you have a frame con­struc­tion that has a depth of 1.2in/3 cm, you will end up with a dis­tance between frame and wall of 1.2-1.6 in/3-4 cm which is per­fect­ly fine and help­ful for prop­er ven­ti­la­tion of the elec­tron­ics.

My rec­om­men­da­tion is to look for a screen that has a total net depth (=with­out the mon­i­tor stand) of not more than 1.2-1.6 in/3-4 cm. The final dis­tance to the wall will increase a lit­tle bit any­way with cables.

Power consumption - don't make your electricity bill go up

My first dig­i­tal pic­ture frame built in 2005 had an ener­gy con­sump­tion of about 60 watts, my lat­est one from last year only 20 watts. The dif­fer­ence was the more mod­ern IPS tech­nol­o­gy which is a lot more ener­gy effi­cient than the old­er dis­plays.

Elec­tric­i­ty prices vary great­ly from coun­try to coun­try, but as your dig­i­tal pic­ture frame is like­ly to be lit around 16 hours every day, it does make sense to choose a mon­i­tor that is both excel­lent and friend­ly to your wal­let.

A mod­ern 24 inch­es mon­i­tor should not exceed 20 watts in pow­er con­sump­tion with no com­pro­mise on image qual­i­ty. There are even good mon­i­tors that only con­sume 10 watts.

Stripping it down to the core - how to peel your computer monitor

The ques­tion is, how easy it is to take the mon­i­tor apart so that we can put it into the frame.

Usu­al­ly, the mon­i­tor, pow­er sup­ply and LCD con­troller is one unit and you only need to remove the front bezel.

If the dis­play comes in a met­al hous­ing, it will be com­pli­cat­ed to take it apart. Most of them, how­ev­er, come in plas­tic enclo­sures which are easy to dis­man­tle. Those are the ones that you should choose.

This is a point that requires some con­fi­dence, but you may find just the right instruc­tion video on YouTube for man­u­als. Tools like the ones sold by iFix­it are very help­ful for this, but the com­plex­i­ty is low­er than you would think.

Internal or external power supply - both have their trade offs

Does the mon­i­tor have an inter­nal or an exter­nal pow­er sup­ply?

It used to be that all mon­i­tors had an inter­nal pow­er sup­ply, but with the intro­duc­tion of mod­ern dis­play tech­nolo­gies and the ensu­ing reduc­tion in pow­er con­sump­tion, many mon­i­tors nowa­days have an exter­nal pow­er sup­ply.

Dis­plays with exter­nal pow­er sup­plies tend to be slim­mer, but then you need some space behind the frame to put the pow­er sup­ply block in. If it's exter­nal, check how big the pow­er sup­ply is and if you can fit it behind the frame.

Dis­plays with an inter­nal pow­er sup­ply should have a down­ward fac­ing con­nec­tor which will reduce the space between the frame and the wall (like with the HDMI con­nec­tor). If that isn't the case, get right angle pow­er cables.

What you don't need to care about:

Touch screens

For a large dig­i­tal pic­ture frame, I have found them of no use as the con­trol hap­pens with your mobile phone, desk­top com­put­er or via Alexa/Google Home voice com­mand.

Monitor Stands

As the dis­play is being stripped any­way, the mon­i­tor stand will be put removed. Unless of course you don't want to put the frame up on the wall but put it on a piece of fur­ni­ture instead.

Speakers

As the pic­ture frame is about image and not sound, they won't be need­ed.

Conclusion

I hope these points will prove to be help­ful when you go on the search for your dis­play for your Rasp­berry Pi dig­i­tal pic­ture frame project. It makes great sense to put some thoughts into this.

Of course, you can pick any old dis­play that you have lying around, but if you love your pho­tographs as much as I do, invest $150 in a good dis­play. After all, you haven't bought an expen­sive cam­era to show your dig­i­tal images on an infe­ri­or screen.

To make it even more con­ve­nient for you, I will short­ly upload a list of rec­om­mend­ed com­po­nents that I had a good expe­ri­ence with, and add it to the Buyer's Guide sec­tion.