What makes a photograph truly “great”? It’s a million dollar question (sometimes several million…) and one that isn’t easy to answer, but each month we ask our 500px Guest Editors to give it a shot.

These editors — who each get a month-long turn selecting their favorite images on 500px and bestowing the coveted “Editor’s Choice” stamp — are some of the best photographers on 500px and, indeed, in the world. If anybody has a chance of shedding some light on the secret behind great photography, it’s them.

Today we pose this question and more to three of our esteemed editors: Portland-based travel photographer and Sony Artisan Brian Matiash, macro insect photographer Ondrej Pakan, and Icelandic landscape photographer Iurie Belegurschi.

Brian Matiash

Brian Matiash is a Portland-based travel/landscape photographer, author and member of Sony’s Artisans of Imagery program. Admittedly, he has a [not-so] tiny obsessions with long-exposure photography, neutral density filters, and fisheye lenses.

500PX: What, in your opinion, makes a great photo?

BRIAN MATIASH: Instead of conjuring up some musings on what makes a good photo, I’d rather share this brilliant quote by photographer Philippe Halsman. I love it so much that I’d honestly consider getting it tattooed on my arm:

A photographer worries about composition, timing, lighting, texture, design, unusual angles, print quality, etc. but all this is not enough if the photographer has no depth and perception. A portrait is not a portrait if the very essence of the subject is not captured; a picture of a scene is just a snapshot if its meaning and emotion are not caught. But even then, everything is futile if the onlooker has no sensitivity and imagination.

What’s your favorite photo from your own archives, and what’s the story behind it?

BRIAN: This is one of my favorite photos ever taken and it means a lot to me for several reasons.

BRIAN (continued): It was the first time I had ever visited Silver Falls State Park and my reason for going was because I saw this same photo hanging on the wall of a colleague’s office. The overall composition was the same but the time of year, weather conditions, and post-processing methods were totally different.

Still, something about that photo resonated with me so clearly and I asked my colleague if he’d be willing to take me to this spot. He obliged, and when we arrived, I remember being overwhelmed with a feeling of satisfaction over seeing this place with my own eyes. There was a beautiful fog rolling through and it become backlit by the setting sun. The lack of wind also prevented the branches and moss from flailing around. Everything just fell into place for this one perfect photo.

What was your favorite Editors’ Choice pick and why?

BRIAN: This Editor’s Choice selection goes down as my favorite pick for several reasons:

First, the exposure and processing techniques used in this photo are very near and dear to me. I take this form of long exposure photography very seriously and I am so happy when I see it done well, as was the case here.

On top of that, this photographer managed to capture something that is easily in the top 3 of my own bucket list, and that is seeing lava flowing into the ocean in Hawaii. I am especially fond of the thin tendril of lava flowing in. The way the color contrasts against the rest of the photo is brilliant and elegant.

You can see and hear more from Brian by checking him out on 500px, visiting his website, or by giving him a follow on Twitter and Facebook.

Ondrej Pakan

Ondrej is an incredibly talented macro photographer who spends his time revealing the miniature world of insects to the rest of us. “We can discover a world of small monsters,” he writes. “Each fly, bee and spider is a perfect predator or a warring victim in this empire.”

500PX: What, in your opinion, makes a good photo?

ONDREJ PAKAN: A good photo needs to have a spirit — something that makes it unique. These are the photos that stick with you for days and weeks after you see them. Here are some examples.

Very nice dark light with good composition:

Action photo with super technical quality and sufficient DOF:

Nice — heartfelt and, again, cool light:

What’s your favourite photo from your archives, and what’s the story behind it?

ONDREJ: This is definitely one of my all-time favorites:

ONDREJ (continued): I have my favorite place by the road to work — it is small lake Dubnik, where there are many kinds of insects. I can take macro picture with blue, green, red, brown… dragonfly.

My speciality is dewy bugs, and I like morning after rain or early morning when is cold with dew caps. I like this picture because is was misty weather and I found three damsel fly on a cane and at the back was orange flowers — it made a perfect background.

What was your favourite Editors’ choice pick and why?

ONDREJ: I’ll pick three.

This is really fantastic light… like a tiny, natural lamplet:

I like underwater pictures, and this one offers a dynamic, face-to-face wide look:

As you could probably guess, macro is my favorite. I like natural macro with good light and technical quality:

You can see a lot more of Ondrej’s work on his 500px profile. We’re particularly fond of his specialty: dew-covered insects. The close-ups are nothing short of stunning. Enjoy!

Iurie Belegurschi

Iurie is an Iceland-based landscape photographer who takes full advantage of the spectacular vistas that make up his backyard. He runs Icelandic photo tours and workshops, and has been published world-wide in books, calendars, greeting cards, magazines and some of the most popular newspapers like: The Daily Mail, The Independent, The Sun, The Huffington Post, The Telegraph, and more.

What, in your opinion, makes for a great photograph?

IURIE BELEGURSCHI: There are many ways on how to judge a good photo. Oftentimes we are driven by personal preference, or by what is deemed popular by the general public. For those who have been out in the field shooting various terrain, weather conditions, great sunsets and sunrises, all would agree that every spectacular photo carries that right “balance of elements from all ends of the frame.”

Take this example from Alex Noriega entitled Arcadia.

IURIE (continued): The foreground automatically captures your eye, yet there is room to roam around the depth of the image to the distant field and mountains, the sunburst accentuated with the tree. The exposure is spot on, with the controlled highlights and the true blacks and shadows adding that needed “moody” umph to the frame.

What’s your favourite photo from your archives, and what’s the story behind it?

IURIE: It might surprise many, but one of my top picks from the archives is a shot called “When the Magic Happens” taken from Seljalandsfoss. Yes, the shot is not from Jokulsarlon nor from Kirkjufell, which are the more famous landscape locations in Iceland.

IURIE (continued): As a photographer that travels around Iceland almost year-round, I have moved from being location-driven to moment driven. Waiting by the side of the waterfall, I could see a little cloud break from the horizon that could give an opening for the sunburst that would add to an otherwise typical frame, casting its golden orange sunset color diagonal through the landscape.

When nature surprises you, when the wait churns out the unexpected, those are the landscape moments we should be on the lookout for, in today’s talented landscape environment, your best weapon could very well be your patience and determination.

What was your favourite Editors’ choice pick and why?

IURIE: This shot from Gunnar Gestur, Fimmvorduhals 2010 eruption is tops on my list for Editors’ Choice — for the simple reason that it is not everyday that we are reminded of the force of nature.

Images like this remind us of how small we are in the grand scheme of things, and how we strive as landscape photographers to showcase the beauty and wrath of mother earth.

At the end of the day, we remember not the best location, not the best foreground, but those amazing moments that we have worked so hard to capture. Images that define our life’s work, not the hunt of images dictated by popular demand.

For more from Iurie or if you’d like to have this incredible photographer lead you around Iceland, visit the Iceland Photo Tours website, check out his 500px profile, or give him a follow on Facebook.