Lenses: Sexy versus useful. I'm leaning toward useful.

It's a near constant in photography; we all love the idea of the fast glass with the rare earth elements and the big expanse of glass across the front. It comes from a constant source of self-delusion, we think that lenses with big apertures and the ability to suck in billions more photons per nano second will make our photographs mystically marvelous. I've fallen for the trap over and over again. I got caught again in the snare just a week or two ago and a few weeks before that as well. 

I think the lens sickness is even worse for people who shoot smaller format camera systems. We're subconsciously (or with both eyes wide open) trying to compensate for the more limited ability to put stuff out of background in our photographs by constantly looking for lenses at every focal length that might be a stop or two sharper than the standard/serviceable lenses at the same angle of view, always hoping that the newest lens computations, coupled with premium glass, will give us high sharpness and the ability to do what our full frame cameras seem to do in a more effortless way; drop things out of focus.  

Here's some advice from the field: Don't bother spending the big bucks to go from f2.0 to f1.2. You won't get what you are looking for and you'll spend dearly for the privilege of trying. 

I packed up my fast glass this last week and went off to shoot an advertising/marketing job. I had dreams of shooting heroic faces framed against gelatinous nothingness, important machines separated from their stark backgrounds by the laws of optics and physics but in nearly every case the regular and routine photos that I take for work (and for play) seem to call for more detail, more context, more  parts in focus. 

There were a few shots where I needed to isolate a small, handheld object; in almost every situation I found that "longer" was just as good or better than "faster." If I wanted to isolate an object then stepping back a few feet and zooming in with a longer lens nearly always was more interesting and effective than staying close and trying desperately to accurately maintain focus through the process. 

The new, sharp, Rokinon 50mm f1.2 UMC was out of my camera bag and on my camera for a little while during the shoot but it quickly became obvious to me that in the modern age a lens like the 12-100mm f4.0 Olympus Pro zoom could run circles around the more traditional lens. Even though it's (gulp!) three stops slower.  It was just so much easier to get exact composition along with a perfect balance of sharp and unsharp with the zoom. 

The Online Photographer recently ran a series of posts about picking lenses. One of the articles proposed a "nested" approach to lens buying. The idea is to buy an all purpose zoom like the 12/100mm. Ostensibly you'd buy one which had a focal length range that is centered around your preferred angle of view, and the lens would also have a high enough performance to be sufficient for the bulk of your work. The lens would probably be bulky so the other part of the advice was to also choose a second lens that would be a single focal length lens also having high performance and, perhaps, a fast aperture. One would use the all purpose lens for .... all purposes and use the nested, "prime" lens for those times when you wanted to divest yourself of the burden of hefty machines and get more in touch with your photographic spirit animals. 

I'm on the fence. I think it's great to be able to change your perspective on lens choice day by day but at other times I pine for the discipline to understand and accept that a lot of lens buying is just emotional compensation for not being as good at this art/craft as I should be after years and years of practice. 

Lenses, especially zoom lenses, have gotten really good lately. Cameras have more or less pounded down the need for high speed apertures to prevent noisy files. That means the only real reason to own "fast glass" now is depth of field control. I guess it makes a certain about of sense to have some fast, middle focal length options. Maybe a 50mm equivalent and an 85-90mm equivalent as well. For those times when the background is just trashed; or needs to be trashed. 

But if I were putting together a system and wanted to stay within a limited budget I'd be looking at all purpose zoom lenses first and foremost. If I still shot Nikon my first lens would be the 24-120mm f4.0. If I were still in the Canon camp it would be the granddaddy of wide-ranging normal zooms, the 24-105mm f4.0. If I were still banging away with some full frame Sony bodies I'd be all over the new 24-105mm G f4.0 lens. In the m4:3rds realm it's always a toss up between range and speed. I made my choice with the Olympus 12-100mm f4.0 but I have a feeling I'd be just as happy with the Olympus 12-40mm f2.8 or even the Panasonic/Leica 12-60mm f-something to f-something.

I've found that these are the lenses that most people; pros and amateurs, use 90% of the time. The next up would be longer and faster zooms like the venerable 70-200mm f2.8s and equivalents. In last place are the wide zooms and after that, and only then, do people pull the primes out and frustrate themselves with tightly constrained choices. 

These are transient thoughts. A hangover from my daylong shoot last Saturday. Ask me again tomorrow and I'm sure I'll be extolling the virtues of my collection of prime lenses once again. But stick around and watch me pack that camera bag for the next job. It's zoom rich. It's prime poor. 

I chalk it up to the mythic boundary that supposedly exists between our professional work and our avocation.  

2018 Lens of the year. Yes, I know. It came out a while ago...

Random hat shot. Concentric circles and oddly sensual curves.

Out into the un-Austin parts of Texas to photograph for a radiology practice. Kinda fun.

Once again, the photograph here has nothing to do with the written content of the blog. It was done for fun with a G85 and a 25mm Panasonic lens. 

One of the interesting challenges for photographers who shoot a lot for medical practices is that presented by M.R.I. machines. These diagnostic machines create incredibly powerful magnetic fields that can strip the information off your credit card mag strip in microseconds. They can be dangerous. Any object that is ferrous can become a deadly projectile if it's inside the room with an active MRI scanner. Especially with the new, more powerful 3T generation of scanners. From a strictly photographic perspective the real issue is that you CAN'T take a camera into the scanner room and you certainly can't take lights and stands into the area with you. Anything you do to better photograph the newest MRIs will have to be done from beyond the doorway, or when the machine is off.

Here's the problem with turning off an MRI scanner: turning it back on and getting it back up and running can cost nearly $100,000. Yikes! You don't want to be the guy who takes one of these medical diagnostic machines offline...  And if you did happen to find a current MRI scanner that was down and could be accessed for a photo shoot you wouldn't have the benefit of the wonderful "running" lights and illuminated information panels that add the polish to the pictures.

Our first series of shots on Saturday morning were, of course, the new 3T MRI scanner at a clinic in Kyle, Texas. Since this was not my first rodeo with radiology I knew not to go past the MRI door alarms with things like my cellphone in a pocket, my good watch on my wrist or my wallet full of super high (ha, ha!) credit limit credit cards on my person. I didn't wear those Red Wing boots with the steel toes and I double checked to make sure none of my dental fillings were cast iron.

I took these precautions because I knew the first thing I'd be doing on Saturday morning would be cleaning and straightening all the stuff that piles up around these giant machines so I would not have clutter in my finished photographs. There was an angle from the door way that allowed me to capture the whole machine in a frame and I used the 8-18mm lens on a camera about three feel back from the door way to make a "portrait" of the MRI scanner. It was during this first shot that I realized how much I depend on just a blush of light to make a photograph work. Since I couldn't put lights in the room and was relegated to just using the existing fluorescent "can" lights in the room I tried all the tricks one can find on modern cameras, including the built in HDR which went a long way towards taming the shadows.

The real issue was when the clients wanted to construct portraits of the technicians who operate the scanners, in the room with the scanner. Again, since I couldn't light the portraits in any style I fell back on trying to position the techs so the light from the cans didn't fall on them directly but was, in a  sense, a feathered penumbra of light. At our first stop we photographed our models having regular scans and also biopsy scans. We had a resident expert on protocol with us so we wouldn't make any of the gaffs that sometimes occur. My favorite (self-deprecatating) medical faux pas (a long time ago) was to photograph an operating room scene in which the anesthesiologist had on neither gloves nor a face mask..... He was a real anesthesiologist so I thought he would know his way around the O.R..... (never assume).

We moved on from there to sonograms, mammography and various other modalities of diagnostic breast imaging. We used, mostly, Godox flashes on lightweight stands which could be controlled from the camera position. Two bounced off the acoustic tile ceilings and, typically, one used as a main light coming from a side angle and modified with a 60 inch photographic umbrella.

There wasn't anything technical to slow us down but there is always a molasses effect when using amateur talent and that involves their self-consciousness at being directed and photographed and their inevitable attempts to use humor to compensate. The marketing mission is always to project confidence from the people in the photographs and, usually, a big grin is antithetical to the serious gravity that a medical practice, which is based on ferreting out cancers and other life threatening issues, wants to portray to the public.

All you can really do is let the giggles and group dynamic run its course. That, and take a lot of images in the hopes of wearing down the grinning facades and replacing them with an almost tired resignation. Best case scenario is the medical tech that arrives in newly pressed scrubs, has no visible tattoos and has a confident bearing. One on a tight time schedule is even better as there is less playful banter and less messing around.

I worked on this project, with master assistant, Amy Smith, all day Saturday. We did about 25 set ups and shoot promiscuously in order to get just the right expressions, no blinks and good synergy between our model "patients" and our volunteer techs. By the time we wrapped up I'd shot about 1,400 raw frames and was on my third battery. Batteries go quicker when the camera's live preview is always on, but having a good, live preview means the client can always see and approve images as we go along.

In the early hours I tried to press my new, fast lenses (Sigma 30mm f1.4 and Rokinon 50mm f1.2) into service but in nearly every case it was important to show context --- or at least the expensive machines which were the subtext for our project. This meant we wanted sharp focus on faces and acceptable focus on our machines. The back walls could take care of themselves.

The two lenses that made life easy for me were, of course, the Olympus 12-100mm f4.0, and the Panasonic 8-18mm. Each had an important place in the process. But towards the end of the day I started feeling as though I could have done everything with the 12-100mm and not bothered to bring along the backpack with the rest of the lenses. To be able to go from a wide shot of an exam room with a bed, a scanner and two people to a tight shot of a biopsy needle held by a gloved hand was great. Even better was that at either end of the focal length spectrum the lens delivered sharp results.

We packed up around 5:00pm and headed back to Austin through the gray of a cool and overcast winter day. It was nice to work with Amy again. She was instrumental starting about a decade ago in helping me organize the photography for all five of my photography books and sourcing talent for the illustrations required. She's been working with more video and film directors lately so I hope to incorporate her into future film projects.

I'm not used to being assisted that much these days but it's really great to have a second set of eyes on the set looking for visual trouble and squashing it quickly.

If there is anything I'll change in our next radiology encounter it will be to use our Atomos Ninja Flame monitor to do our previews on. The bigger screen, which is able to be calibrated, would come in handy for aiding clients in seeing what the finals will really look like.

We're back at work here. I was working on a video edit all day yesterday and I sent it to my client for review last night around 11:30. I got notes back at noon today and, as always, I'm trying to figure out how to get it to shrink from 4 minutes to 2 minutes. Some sort of magic trick involved? We'll get out that editing knife and see what can be cut....

The raw files from the GH5 are beautiful and the rendering of flesh tones is nearly perfect. I have a little card in my camera case to remind me of the best ways to fine tune files. Always white balance each scene first and then figure out exposure. Changing white balance after setting exposure can cause the effects of exposure to change. Focus on faces when in the scene, at all other times focus one third of the way into the scene and calculate depth of field to cover.

one other note: I played with a Panasonic G9 recently and love the new viewfinder. Am currently considering (but have not decided) to trade in my G85 and get one of the new cameras. Might just be a waste of time, money and energy but....

Why I keep coming back to the clever and elegant Panasonic G85. Especially now that I've found a great companion lens for it.

Tomorrow morning first assistant, Amy Smith, and I will meet at the studio, pack the car and head to Kyle, Texas for a daylong adventure in commercial photography. We've been awarded the assignment of photographing, in detail, the operation of a large radiology clinic there. We'll be photographing architectural documentations, procedures (with actors and technicians, but not with real patients...) and encounters with machines such as MRIs, CT Scanners, Mammography Imaging Scanners and much more. 

In this instance we are NOT taking everything in the studio with you. I'm limiting the lighting gear to only what we can comfortably fit into a rolling case (see above) but that does include: Three Neewer Vision 4 battery powered monolights, one Godox AD200 flash, and two Godox V850s with their rechareable lithium ion battery packs. At first glance this may seem light but I'm really packing two systems; mostly for redundancy. 

My well worn plan is to use the three bigger, monolight flashes for everything. Two bouncing off white ceilings and walls and the other one adding directional fill from a 60 inch white umbrella. But if the schedule drags out and the batteries start in the big units start to falter I'll have the more pixie sized flashes on which to fall back. I may approach it the other way around and start with the pixie flashes and work my way up. 

The power of the flashes hardly matters. The clients and I had a meeting on Monday to discuss creative strategies and the "look and feel" they want to get in the photographs and actually less powerful (but no less controllable) lights might actually be beneficial. We want to shoot as wide open as possible in order to de-emphasize the backgrounds. This means we'll need to work mostly at f2.0 or f2.8 for effect. Even at ISO 200 it means that most of the lights will be operating in the 1/32nd to 1/64th power area and we'll need to be cognizant of "bleed" light from existing fixtures around the facility. No sense getting a great shot if we also get a lot of green tinge.

So, one roller case filled with lighting goodies and one Amazon Basics backpack for all the camera gear. Seems like a recipe for moving quickly while retaining good control of the lights. 

We'll be working with the two Panasonic GH5s and shooting raw format all day long tomorrow. I thought I'd take a day off today and blow off some steam (and lingering anxiety0 by heading out for a walk this morning with what has to be the most comfortable and amiable camera I've ever, ever used: The Panasonic G85. With a whopping 16 megapixels of super-charged pixels and a shutter that's a sweet as an Adele song, the G85 is a stellar traveling companion. Across town or around the world. It's compact, smooth and, with the right lens, it can be a bit of euphoria in your hands. Yes, that's called "hyperbole." But in fact, the camera is a very, very well designed and implemented companion camera. The EVF is transparently invisible, the shutter sounds nicer than the gentle closing on a Bentley door, and the image stabilization is top tier.

My latest engagement with the camera was also an opportunity to test a lens I've had on hand for a while but have ignored, for no good reason. Maybe it didn't seem sexy enough just sitting, forlorn, in the drawer of the equipment cabinet... It's the 25mm f1.7 Panasonic lens that is often on sale for $149 and worth at least a hundred dollars more.

I thought it would be the perfect companion for the G85 and I was exactly right. I used it wide open, and at apertures up to f4.0, and was happy with the sharpness at every f-stop. It was a lens that instantly helped me channel my "Henri-Cartier-Bresson-Robert-Frank-Lee-Freidlander" classic vision. A vision in which the subject is king and not the visual strutting of unusual focal lengths with all their hysteric frippery. I was so happy shooting with today's combination that I neglected to stop in any of my favorite coffee shops or bakeries, such was my passion to continue on with my addictive photography rig. No visit to Voodoo Donuts. No cappuccino at Medici. No Vegan Lemon Hazelnut Scone at Whole Foods/Amazon. Just walking, shooting, walking, shooting. 

It was 55 degrees and breezy when I started my walk and by the end we were careening toward the high sixties and that sweatshirt that felt barely cozy at the outset was starting to feel overly warm. Ah, winter in Austin. A few days of bluster and weeks of swimmable weather. Below are images I shot this morning.

Woke up this morning in the undecided category.

 I envy those people who have one overriding sense of purpose in life. One all important goal at which to aim. They can wake up in the morning, drink their orange juice, and just get the ball rolling in the same direction they always have. Not so easy for those of us who intentions and interests are divided. (Just for the record, I absolutely hate orange juice. I am not anti-orange but orange juice seems to me to be disgusting, and always too sweet).

I woke up this morning and felt a wash of frustration froth over me. I love taking portraits. I love writing. I love walking around town with a camera in my hands; not in endless pursuit of the ghosts of H.C.B. or Robert Frank but as an observational walking meditation. The problem for those of us with multiple interests (those who've taken off their culturally induced career blinders) is that to excel at either portraiture or writing I think one has to commit and make a singular pursuit a priority. But, of course, I'm from the generation that wants it all and, in truth, has been fairly successful in getting most of it.

The pursuit of cameras, as Michael Johnston is engaged in on his wonderful blog, is a great way to sidetrack one's self into not deciding anything at all. You can research, test, buy, review and re-sell cameras all day long and they become their own occupation --- separate from taking the photographs you think you'd like to take.

Part of my ennui is that I'm satisfied with the cameras I have right now. Even the lesser cameras like the G85. Part of my lack of motivation to push photography harder in the business realm is that I'm not really forced into the hot pursuit of money. The issue with getting a second novel out is the same issue every dilettante writer has; it's hard as hell to get started ---- again and again and again.

Some days, lately, I feel as though I am stuck in quicksand. On those days the most helpful pursuit I can think of is.....a long walk. And a bit of introspection. I'm better at the walking part.

We should all be working 

on our next project.

Otherwise nothing will get done.

If only I felt certain about the nature

of the next project...

The Curious Incident of the Zoom Lens that acts like a bag full of primes.

It seems like I never stop learning about how to push back on the perceived limitations of the photographic process. I've been locked in a battle that resembles a sine wave. I want to do things in a different way than before but I come to doubt my motivations or my resolve or even the premise of my undertaking and then rush back in the old direction to re-embrace a comfortable but unexciting methodology. I swing from risk to comfort like most people. I guess our hope is that each swing into newer territory has us walking forward by five feet and retreating by "only" fifty-eight inches once we lose our nerve...

I'm back in the m4:3 sensor camp for now. It will take a bit to nudge me away this time because the format caught up with where I always wanted it to be. 

I have a confidence in the format now that I never used to and a belief in the best lenses for the system that dwarfs what I felt I got from large format system lenses.  In a sense so much of why systems excel or fail has to do with the synergy between body and lens. 

I was at ZACH Theatre last night photographing a new production called, "The Curious Incident of the Dog in the Night-Time." The play is from a popular novel the protagonist of which is an autistic teenaged boy in England grappling with a shifting and ultimately unsettling family landscape. The play depends on projections and dramatic light changes to push the audience into the mindset of the main character. 

It is harder to photograph plays that are about ideas or about concepts than to photograph more "narrative" plays and plays with multiple scene changes and costume changes. Those productions have visual texture on which to hang technique. This play is more cerebral and spare. But, of course, I gave it my best shot. Or multiple hundreds...

Given my selection of the first five images in this blog you can see the scene I liked best; in visual terms. It's meant to be a small group of people standing next to a subway track, waiting for the next train. Our hero, in the red jacket, is observing so he can learn how to use the "tube." 

Last night was my first attempt to use just one camera and just one lens to photograph the complete dress rehearsal of a play at ZACH Theatre. We had a live audience and I was constrained, once again, to be mid-house; half way up from the stage and pretty much dead center. It should come as no surprise that I was using the GH5 camera body nor that my choice of lens was the Olympus Pro 40-150mm f2.8. With this system if I could see something clearly on the stage the camera was able to lock focus instantly and capture the image without much fuss. 

This series (the first five) of photographs documents a scene set near the rear of the stage. I needed the full reach of the lens for the tighter crop and still a tight focal length to get everyone at the "stop" from head to toe. 

Since the lens is as sharp as the sting of a wasp, even when used wide open, I had no reason to stop it down. At f2.8 I was able to stay in the 1/250th to 1/400th shutter speed range, and I kept  the ISO at 1600 for the entire evening. If one part of the exposure triangle needed to be changed to compensate for changing light levels it was always the shutter speed I chose. 

I watched part of the tech rehearsal on Sunday evening and I quickly surmised that the color temperature of the light on our people changed frequently and, massively. With a warm light cue the dominant light on stage was around 3200K, + or - 200K. In the cooler cues the lights sat at around 5700K with a healthy dose of magenta in the mix. On this play I set up three different white balances in the custom WB settings. As I was shooting I'd watch for different light cues and assess their white balance. With the camera to my eye I could hit the WB button on the top panel of the camera without having to look. The submenu opened to the current balance and the flick of a control wheel took me to the next white balance. One hits the "set" button to make the change. 

Setting up the camera in this way, and having an easy "touch to identify" physical button meant that I could soon make the changes almost subconsciously. This turned out to be a time saver in post; I was in the ball park in nearly every situation and could concentrate on just tweaking exposures and shadows for my conversions to Jpeg and subsequent delivery. 

Following along on my "one lens, one camera" experiment last night I can also report that the entire evening's shoot was accomplished with just one battery.

It's odd to try to watch a play and to photograph it at the same time. There two completely different brain uses involved. One is passive observation while the other is active editing with continuous, mini, calls to action. Look, frame, commit and then push button. Repeat. If I knew a "non-photogenic" few minutes came along in which I could put the camera down and just watch and listen but there was an inertia that slowed me down from switching back over the active mode. It seemed like a case of always wanting to be doing the opposite thing. 

So, I was working at ISO 1600 and, in post, boosting shadows in Lightroom by plus 25 or plus 50. I was also tweaking exposure, adding anywhere from plus a quarter stop all the way up to adding a stop and a half of exposure. These are all things that should lead to noisy files. Especially in shadow areas. But when I look at the images I've included here I find them to be no more noisy than the images I used to get from my Sony A7ii or A7rii. In any event files from either system were easy to "sweeten" with a judicious lean on the noise reduction functions in Lightroom or PhotoShop. 

Where does this leave me? I'm currently thinking that all cameras are good but that all cameras take time to understand and time to practice with. There needs to be a shoot-look-shoot-look break-in period. A time in which you learn where the breaking point is for files from each system and each model. You learn where these negative inflection points are and then you learn to compensate for them. And if you are doing your job right you come to find that, with a few tweaks, the camera you enjoy shooting can pretty much match its competitors for image quality. Now you can safely choose the cameras you want to use by how they feel in your grip and what kinds of features you think are most beneficial to the way you work. 

I must say that my regard for the GH5 cameras grows with every use. The bodies are extremely solid and convey a sense of indestructibility. The files seem to say to me that if I do everything in "best practices" mode I'll be rewarded by beautiful technical file attributes. 

Nail exposure = get no noise. Hold the camera still = get sharp photos. Nail the color balance = get malleable and pleasing color right out of the camera. 

These practices are not limited to a brand or a format but are things we should be consciously practicing every time we do work with our cameras. 

After reviewing the 600+ files I presented to the client today I have to say that my purchase of the Olympus Pro series 40-140mm f2.8 lens is one of the smartest purchases I've made for photography in the last year or two. It makes my work look better than it should. Actually better than a bag of primes...

"The GH5 and the GH5S are so big! Why are they so big? I thought the whole reason for making m4:3 cameras was to make tiny, tiny, tiny cameras. And lenses! Right?"

No. Wrong.

If you look at cameras as wearable jewelry you could be forgive for imagining that the new generation of smaller sensor cameras should be tiny enough to wear around your neck on a chain. Or fastened, all bling-style, to a heavy, gold-plated wrist chain that also features the dangly parts emblazoned with signs of the zodiac and your various allergies to medications. 

If you really want a camera that fits in all your pockets it really does make sense for you to pick up a nice phone and learn to use its feature set to its highest potential. If you are looking for a camera that's small enough to do your own D.I.Y. endoscopy/colonoscopy then I suggest that you may misunderstand many of the reasons that we own the cameras that we do.

I can't think that anyone with a functioning brain looks at a GH5 and thinks, "Yep. That's the camera for me. It's so teeny-tiny. I'm sure it will fit in the watch pocket of my Levi's 501 classic jeans...." The reason for the GH5's existence and popularity have little or nothing to do with its size relative to other cameras and everything to do with its deep list of features and capabilities. 

Let's start with 4K video. Yes, Sony offers 4K video in some of their A7 cameras but there are some caveats. First of all, the entire Sony line conforms to the EU standard of limiting recording time to slightly less than 30 minutes. With a GH5 you can record until you run out of space on two UHS-11 cards or until you run out of battery juice. Put two V-90 SD cards in the two slots on the camera, add a battery grip to the bottom of a GH5, and you'll be able to shoot for hours and hours. Your only limitation will be the size of the files you choose. And, unlike the Sonys, you can shoot All-I files at up to 400 megabits per second directly in the camera. OMG! That's insane. But good insane. This capability alone creates a demarcation between professional and advanced amateur when it comes to video equipment that can really be used in the field. Nikon, Canon, Sony, etc. None of them can match this kind of performance, even at two or three times the price. 

But there's more. The Panasonic is seemingly impervious to the heat generated when making enormous, detail rich files. But not so with the Sonys we've owned in the past. All but the RX10 series have been plagued with thermal shutdown issues. There is a workaround that was introduced to quell consumer revolt with the A7Rii model and that was to allow the temperature to rise and allow the cameras to deliver noisier and noisier files. Panasonic purposely designed the GH series of cameras to handle heat by making them big enough and thick enough to house highly effective and highly efficient heat sinks. I've run my GH5s for several hours in Texas Summer heat and never had an issue. I've run various Sonys in the studio and suffered heat warnings. An amazing achievement by Panasonic when you consider that the camera is pushing through about 4X the data stream that the Sonys are managing....

Apparently Panasonic is using the total volume of the GH5 body in a way that maximizes performance and equipment longevity while ensuring the highest quality of their files in actual daily use. Now that's novel. 

The Panasonic pro bodies are also subject to being paired with professional quality lenses. The lenses, not compromised by size constraints, are being designed for sheer optical quality. In this instance I am thinking not only of the professional caliber lenses from Panasonic but also from Olympus. Some pros demand a "no holds barred" optical performance from their lenses and the get it from the high end products offered by Olympus and Panasonic. Some of the fast (and glorious) lenses such as the Olympus 40-150mm f2.8 Pro from their Pro series are built like tanks. They are hefty. And if you are going to hang them off the front of a camera you need to design that camera's mount, and the surrounding infrastructure, to handle the load. This means that the mount and camera in general have to be generously sized to ensure longterm plano-parallelism and reliability. Logic dictates a certain minimum camera size for that as well. 

Now we have two things that mandate a certain camera size: mechanical tolerances with high reliability and effective heat dissipation/management. 

We can easily toss in a third parameter that strongly suggests a certain minimum camera body size and that is overall handling characteristics. Is there enough space on the exterior of the body on which to place good, tactile buttons and controls without crowding them and making them tactilely confusing? Is there enough space for professional connection points for things like a full sized HDMI cable, headphone jack, microphone jack? Is the camera comfortable to hold while using a heavier lens? Is the camera body big enough to accommodate a battery that doesn't need changing every 45 to 60 minutes of on time? Can there be a rear screen that's big enough to evaluate stills or video without overwhelming the overall space on the camera back? Is there adequate space for two SD cards slots (both of which are UHS-II)? Can your pinky finger find purchase on the grip of the camera or is it dangling painfully under the body of the camera?

I learned during my time owning various Sony Nex cameras that there actually is a minimum camera size commensurate with sure and happy handling and the Sony Nex cameras that I owned missed that metric by a good 25%. Not so with the professional cameras from Panasonic. 

Finally, uninformed pundits often opine that since the camera is X size it should have a bigger sensor. Generally these people are "pie-in-the-sky" techno-Luddites. They just don't get the idea of compromise. Panasonic might have been able to put in a bigger sensor but they would have had to compromise on: rolling shutter, heat dissipation, file size, writing latency, inferior in body image stabilization, worse performance on most file edges due to optical issues, and they would have had to make lenses even bigger and heavier to get close to matching the performance currently being delivered to the right sized format  of the current Panasonic cameras. 

The GH5 is not a heavy or burdensome camera. Even a feeble and out of shape person like me has little problem schlepping a couple of these around. The people who are calling for ever smaller cameras instead of calling for ever evolving and improving performance are pissing up the wrong rope. They are busy transitioning from the rational pursuit of serious photography into a world of bad fashion and worse user experiences.