Pentax 645z Medium Format Digital Camera Review

Pentax 645z Medium Format Digital Camera Review

We just spent a week shooting the new Pentax 645z, the new, somewhat-affordable medium format system. We wanted to take a real world approach to how we would test the camera, so like most reviews on Fstoppers, this will be less technical and more about how it performed on the job. It was put through its paces at full wedding, a weeks worth of portrait sessions and a night shoot.

Why Medium Format?

Medium format digital cameras have been on our mind lately, as the market is at an interesting point. There are rumours that most major camera manufacturers could be entering the medium format market as early as next year. There is also an abundance of used equipment available and the older CCD backs are great if you are able to shoot everything at base ISO. This is one of the many new medium format offerings to use the 51mp CMOS sensor produced by Sony. This new CMOS sensor is a huge deal for the way we shoot, mainly because it allows useable high-ISO and live view. 

Medium format offers a few great advantages over 35mm: larger pixels, larger files, better color, and leaf shutter lenses. This all came at a cost, as until now a MF kit would set you back between $20k and $40k. It would shoot slow, it might have one AF point, and you would be stuck below ISO 400.

645z portrait

pentax 645z 100% detail view

100% view.

Shoots Like an Oversized DSLR

We chose to specifically not use a tripod and we weren't shooting tethered. We wanted to see if we would be able to shoot it exactly like we'd shoot our Canon 5d Mark IIIs. We found the autofocus to be reasonbly fast in ideal to good light situations and very accurate. The battery lasted much longer than we anticipated- it showed 75% still remaining after being used for a full wedding day. This was also the first time we were able to use workable live view on medium format. The grip feels nice and sturdy in your hand, however the button placement doesn't seem to be as refined as Canon/Nikon. I’d love to see a joystick on the back for moving AF points and the zoom box in Live View. 

pentax 645z couple photo

Dynamic Range

There is a massive amount of detail in the shadows and the highlight retention is decent. I do recommend using live view for real-time blown highlight warnings, it is actually useful because it doesn’t use the preview jpeg to generate the warning, but the actual raw sensor data. Here is a shot that we underexposed by over five stops to test this. The colors stayed true and there were very little noise issues. 

pentax 645z underexposed photo

Before Lightroom adjustment.

After lightroom pentax 645z photo

After ( plus 5 stops in Lr and plus 100 Shadows)

Here is a better real world example showing why this can be helpful for our everyday. Shooting a couple in front of a sunset can be tricky- you want to capture the color of the fading sun and have more than a silhouette of your subject. This is easily attainable by utililzing the sensors dynamic shadow detail. 

pentax 645z dynamic range before edit

Exposed for sunset.

And after a gradient and adjustment brush in Lightroom.

pentax 645z dynamic range sunset photo

Here is an example of a photo as it was exposed in camera, with basic lighroom edit. 

pentax 645z dynamic range wedding photo

High ISO

We set out after dark to take a few portraits of the lovely Jade Rose. We used an iPhone flashlight to light the first two shots and street lamps for the third. Up to ISO 12,800 is no problem, the colors stay accurate and you can still push the files in post. ISO 25,600 is doable under the correct conditions, or makes a great black and white. 

high iso pentax 645z portland photo

ISO 12,800 | f/2.8 | 1/125th

high iso pentax 645 105mm 2.4 photo

ISO 25,600 | f/2.4 | 1/125th

high iso pentax 645z photo

ISO 6400 | f/2.8 | 1/125

Lenses

For lenses, we primarily used the Pentax 55mm f/2.8. The 55mm is equivalent field of view to about 43mm, and it performed well offering very little distortion and great sharpness wide open.

An interesting note about this camera, you can adapt the readily available and affordable Pentax 67 lenses. There are even a few 67 system lenses with leaf shutters, should you need them. We also used the 105mm f/2.4 from the Pentax 67 film camera with an adapter, and presently this is the fastest lens available for the system.

pentax 645z wedding photo

Auto Focus

The 27 point system is clustered near the center of the viewfinder, making it somewhat limiting. We did most of our shooting using the center point and recomposing. It was relatively accurate with most of the images we took being tack sharp at 100%. That said, it was fairly slow, difficult to nail focus on anything moving, and autofocusing in a backlit situations felt nearly impossible. The AF is also very slow and difficult when using Live View, but you can turn on focus peaking and manually focus very accurately.

pentax 645z test photo

The Files

The files are big and beautiful with brilliant color detail. They are the reason you would get this camera. Viewing the files at 100% revealed sharp detail. The files are large (8256 pixels x 6192 pixels), around 60mb each, so editing them takes a powerful machine or patience as a file renders a change. They edit very much like the Canon files we are used to in Lightroom and it was surprising how easy it was to match our editing across the two. 

pentax 645z landscape sunset photo

It hard to see how impressive these giant files are in this post alone, so we wanted to make a few avaiable for you to download and play with. Here are a few example files: 

Full Resolution jpeg

DNG Files: High ISO & Couple Portrait.

We retain full copyright of these images, please don't steal them.

A few more example images:

A portrait of Portland Drum & Bass artist Revival.

pentax 645z portrait

pentax 645z wedding photo

pentax 645z couple portrait

pentax 645z long exposure

ISO 100 | f/2.8 | 5 seconds

pentax 645z portrait

What we liked

  • The incredible files- 51 megapixels with great color, shadow detail, and dynamic range
  • Live view - We use this quite often on our DSLRs, the articulating screen makes overhead or ground level composition a breeze
  • The price- A digital medium format kit for under $10,000

What could use improvement

  • New leaf shutter lenses would be great for studio / strobe use.
  • AF speed could be improved, even though we think it is the best in the medium format game currently


The Pentax 645z is incredible for high-detail, beautiful portraits. I can’t wait to shoot a few landscapes, especially at night. It isn’t for everything and it won’t replace your 35mm... and honestly it shouldn’t. I think we’ll end up adding one to our gear bag and use it along side our other cameras. It will definitely get the call for commercial work, stock photography, and landscapes. Portraits are incredibly detailed and I can’t wait to see some of these files printed huge. This is definitely a game-changing camera and it should prompt a new gear battle in the digital medium format arena.

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24 Comments

Kyle Ford's picture

Great write up man. Looks very promising.

They gave a pretty fair review of it. I'm considering taking ours home from work this weekend.

Joshua Baker's picture

We just shot a wedding, a portrait session and an astro session with it and can echo this review. The files and details are gorgeous! Handling is better than i expected, but man some leaf shutter lenses would seal the deal. 1/125th outdoor flash is hard !

Dylan Howell's picture

leaf shutter lenses are hard to find, but out there for the 67 system. We used the fotodiox adapter and it worked well.

Paul Monaghan's picture

You should be able to use the Dpad on the back to change AF points, it has a double function and if you hold the ok button for a few seconds it should switch between menu and focus points.

I've been shooting Pentax for years and never had a problem with the ergonomics and button placement and find it better than most cameras I tried including the 5d's and d3's.

I haven't had the chance to shoot with a 645z or d though sadly as they are a little out of my price range but to be honest I'm pretty happy with my little DP merrills for capturing lots of fine detail and upto 1/2000 flash sync out doors but they don't have the usability, speed or general usefulness and are more limited than a dlsr but create there own unique little files that can rivial/suprass a d800e in the right conditions

Roman France's picture

Great write up kids! I am interested in the development of Pentax's MF system. I'm also hoping Canon, Nikon, or maybe even SONY jump into the space. I've been hands on with the other two digital medium format players offerings, but I can't invest that kind of money on old (CCD) tech. It also bothers me that these new CMOS offerings offer sensors much smaller than not only proper MF, but of the older CCD medium format backs. I'll give it a few more years before I jump in.

I love my 645z. Next week the tethering software will finally arrive as well. In the human tradition of focussing on what's not so great, here's what could be improved imho:
a) Placement of some of the buttons (back-button focus is awkward), front selection wheel uncomfortable.
b) Tethering solutions. FluCard sucks and Image Transmitter 2 is said to be rather slow, but I can't confirm that yet. No other solutions are available!
c) No external color management system is compatible yet - forget your ColorCheckr for the time being.
d) yep 1/125 x-sync... enough said. You can't go higher then that, which is a pitty, because sometimes, you actually want that unlit bar in the photo you get by pushing past the x-sync speed.
e) There are only a handful of lenses, that are both affordable and capable of delivering the performance you'd need in for the 51 mp sensor. These are the 35mm, the 55mm and the 120mm. The 75mm comes very close, as well as the 150mm. All the other older and affordable Pentax 645 lenses as well as 67 lenses are too soft for the sensor - if sharpness isn't an issue for you, all the better. The new lenses (24mm, 90mm macro) are very expensive! Or at least on par with the same lenses from Hasseblad and Schneider-Kreuznach.
f) At ISO 100 the camera is said to almost oversharpen the RAW file a little. It's of course a matter of taste! I like sharpness, so...

That's all I got. Because apart from these issues, it's by far the best camera I ever had and I've previously shot Hasselblad.

Roman France's picture

So you can't currently shoot tethered to Capture One? Is that a camera limitation or simply waiting on Phase One to update support?

C1 does not and most probably will not support Pentax. C1 belongs to PhaseOne. Here is the funny bit, according to Alex Muñoz, a few versions back C1 was able to read 645z files, but they retracted support. http://www.alexmunoz.net/captured-one/

Rob Durston's picture

I use the fastest Mobi card available and I'm quite happy for the most part transferring the #2 slot jpgs to the iPad.
I'm also looking forward to the studio tethering software, lets just hope its robust enough.

Ricky Perrone's picture

I haven't tried the 645z but I have the 645d and love it. As far as leaf shutters go there are two that work on the camera without adapters a 75mm and a 135mm I have both and they are both tack sharp and let you sync up to 1/500th.

Having rented the Z, and owning a Hass, I have to say there are places for both. The article doesn't cover everything, but I want to point out that I was shooting in the rain - yes, in the rain - with a MF camera (I pull my Hass under my jacket at the first spit of moisture). That by itself makes it more viable for wedding shooters, whom may be out in the elements while a couple are hiding under a *fill in the blank*. Toss in the high ISO performance, and while I don't care for noise in general, it's pretty damn good.

The 55/2.8 is dog slow, but the 80-160/4.5, the 150/2.8 and the 200/4 are all much faster AF, but require attention to microadjustments (one thing I didn't do). The articulating screen rocks, for composing low it is amazing.

One thing some folks may not know is that the lenses are TINY! I mean, they're small for MF - smaller than what I would assume. Here are the lenses next to their HC equivelents: L to R HC 210, Pentax 200, HC 150, Pentax 150, HC 80, Pentax 55. The Pentax 80-160 is the size of the Pentax 200, a fraction of the size the HC 50-110.

" We wanted to see if we would be able to shoot it exactly like we'd shoot our Canon 5d Mark IIIs. " In resolution terms, it's more appropriate to try to shoot with NIKON D810 :) Why ? Because NIKON D810 it's the best DSRL on the market and has much more resolution than canon 5d mark . . . NIKON D800/810 makes price of a medium format camera to fall from 30-40k $ to more affordable ~ 10k $. Try to make an article Pentax 645z vs. NIKON D810 to be very close to the truth :)

Sean Shimmel's picture

I want to believe in some kind of magical difference... but without wanting to sound like a sullen naysayer... clients (nor I) would never realize anything significantly superior with the supposedly better color or file sizes. It's all in the mind's eye. Regarding my Nikon D800, I'll quote the old 80's classic by Trinere... "I'll be all you'll ever need/satisfaction guaranteed/if you give me half a chance I'll rock your world." https://www.youtube.com/watch?v=vOLMdjsRHPE

And to be fair, I'm sure it would play out the equally with a Canon Mark IIIs... satisfaction guaranteed.

Rob Durston's picture

I wrote a mini review a month ago when I passed 10k shots on my 645Z. Its now past 20k.
Here are some more thoughts.

I got it a couple of months ago and have been using it almost exclusively for my advertising work. I'm very happy with it so far, for the most part.
Here are my top TEN lists for it

Some thing that do bother me though are,
1. AF zone is too small (center 25% of the frame only)
2. inconsistent AF accuracy
3. wait time to use the aperture and ss wheels after firing off a frame
4. the grip, too small
5. SD slots too close to strap point, relocate the strap mounts please
6. missing cap for PC connection
7. wait time to turn on LV after firing off a few frames
8. cable release option besides crappy FluCard
9. FA collar AF/MF switch, PITA
10. tunnel like viewfinder, your eye needs to be lined up perfectly to see 100% of the frame

things I love, beyond the resolution, decent lenses (for the money), ISO sensitivity
1. rear monitor, huge
2. dual SD slots, my Mobi wifi card works wonderfully at speed with the camera
3. weight, nice balance
4. solid lens mount
5. side tripod mount
6. comprehensive menu
7. Live View magnification, the only true way I have found to get accurate focus
8. Matrix metering is usually spot on
9. Long battery life, one battery lasts almost all day, around 1000-1300 frames even with the wifi card transmitting
10. Three WB preset favourites, great to swing back and forth through while testing a scenario

I don't use the camera everyday. I now have three systems from 3 separate brands that I use on shoots; Pentax 645z, Nikon D800 (lightweight back up to the 645z) and the Canon 5D mk3 for lighter file size work.
Saying that, I'm working on a 25 day project, shooting 50 locations with 50 hero shots and over 450 extra scenarios. I'm half way right now and the Pentax is shining. Most of the time I don't bother using the other cameras for the smaller or lighter work because I'm enjoying the the Pentax especially with the 45-85 and the 35 prime. The Nikon has been consistently jamming when needed the most and the Canon now feels like a Fisher Price toy.
When I'm done this project I willing be thinking about sending the camera in to have all the lenses calibrated with the body, specifically checking the focus.
Overall I give it an 8.5/10

gabe s's picture

Maybe it is just these photos, but the open field landscape photos look lacking in the color/quality that the portraits seem to have.

Nathan Joseph Dodson's picture

I need this camera. Great work here! Thanks for sharing!

Killer review

Douglas Sonders's picture

great review

vii-photography's picture

Hello , apart from working in medium format and have high image resolution and smoothness related to this type of sensor. I wonder if we really found the characteristic image of the medium format. Color, smooth ect. I find examples of Pentax very Digital unlike hasselblad . Do you know other photographer who work with this material ?

You really should reference something on the Hasselblad side - V or H series, Hasselblad back or Phase One. Lots of different possible references, but without specifics, it's hard to compare. Having a CCD Hass, and having rented the Z, the files are different, but both are deliverable to a client.

Remember, the sensor is really just a larger version of the 36mp D800e/A7r sensor.

Martin Van Londen's picture

Ive been wanting to hear more about camera and get a more in-depth look at it. But what really got me about this was the fact that you shot everything in my home town of portland LOL!

After another rental there are a few things that no one seems to notice about this camera - IT DOES P-TTL!!

Yes, Pentax 540 speedlight, P-TTL flash, and HSS up to 1/4000th of a second. Wireless master and off camera slaves! Speedlights with 51mp! Walk around and shoot with it bouncing a light against a wall, and it's all happy.

Weather sealing I wanted yesterday - literally the dust flying around Mt St Helens was scaring me with my Hass, really wanted the seals to keep things cleaner.

Mark Kitaoka's picture

I am a full time commercial photographer. I have now conducted 17 separate commercial sessions with the Z and could not be happier. This camera fits the niche I occupy. Having used 35mm full frame cameras exclusively for my commercial work I have longed for an "affordable" MF camera. The Z fulfills that need. I rented prior to purchasing and only own their legacy lenses which were all purchased used from Japan. I could not be happier and my clients have noticed the difference in image quality. I have written my own review of the camera here:
http://www.markkitaoka.com/latest-news/pentax-645z-review

I have been severely disappointed with Ricoh's Image Transmitter 2 software and have yet to receive any answers to my feedback. You can read about that here:
http://www.markkitaoka.com/latest-news/review-ricoh-image-transmitter-2-...