Signal Mtn

In Search of the Unicorn

A Review of the Pentax 645D - part 1
The Homecoming

by Miles Hecker


The unicorn is a mythical animal of great grace and beauty. During the middle ages, it was an iconic symbol of wildness and purity, which legend has it could only be captured by a virgin.

In last decade the Pentax 645D has been the unicorn of the photographic world. In development since 2003, it was often seen fleetingly as a shadow in the woods, only to vanish when anyone tried to approach and intern it.

In June of 2010, the unicorn finally made it out of the woods. Accompanied by an otome, it landed for sale in the Japanese marketplace. Being ever so skittish as unicorns are known to be, it wasn't until January of 2011 that it was to make its' debut on the shores of the north american continent.

In mid January 2011, after several calls to Erwin Goldstein, the pro-camera specialist at B&H photo, a unicorn was on its way via UPS to my Wyoming doorstep.

Pentax 645D


I've been involved seriously in photographic endeavors for some 44 years. In that time I have to admit that I've always had a sweet spot in my heart for medium format cameras. My very first camera at the age of 16 was a Ciro-flex twin lens reflex, MF film camera. I still have it! I had a Rollei for many years which was a mighty fine camera by any standards. I had a Fuji 690 rangefinder. Lastly, I had my trusty Pentax 645N, which was my favorite camera of all time. A gem of a machine with a wide assortment of high quality reasonable priced lenses to go with it.

A funny thing happened about 10 years ago in photography, we now call it the digital revolution. In 2002 a company called Canon introduced the 1DS, a full frame digital SLR which almost overnight, killed off the MF market. The Hasselblads and Pentax 645's of the world had been marked, caught and passed in stride. This beast could produce digital files that equaled 6x6 or 645 MF in quality without the film or scans. A wedding pro who shot 100 rolls of MF film in a weekend could pay back the $8000 cost of the 1DS in a matter of months.

I sold my 645Nii body and kept my Pentax MF lens collection, lovingly packed away in a foam lined suitcase, waiting for Pentax to someday produce an heir to its MF legacy.

The Arrival

Like a kid at Christmas I unpacked my shiny new toy and put the battery on the charger. I took one or two quick shots to make sure it was working properly and set out to evaluate my own little unicorn.

Two things jump out at you immediately, the build quality and the viewfinder. The chassis is made of high strength die cast aluminum and it shows. The 645D is solid as a tank. My good friend David Brookover said his D3x feels like a cruiser and the 645D feels like a battleship. The 645D body weighs in at 3.3lbs, the D3x is 2.75 lbs in comparison. The rear section of the chassis functions as a heat sink to release the heat radiated by the 44x33mm CCD sensor.

The viewfinder is big, bright and the equal of the the Hasselblad H3D-39ii that I had used for a week in 2008. It is also brighter than the viewfinder on my old 645Nii. That's quite an accomplishment. Pentax has always known how to build a high quality viewfinder. The 645D viewfinder is better than the viewfinders in any 35mm digital SLR that I've used. This includes the Sony A900 and Canon 1DSmk3.


Pentax 645D

645D level

Little Things That Please

In day to day operation a few more features begin to appear as very well thought out items.

The electronic level is the first. Much like the level on the Nikon D3x, it is a joy to use. Every digital SLR costing over $1000 should have this feature. It can't cost very much to implement.

The second is the dual SD memory card slots. Any camera costing over $1500 should have this feature. No fumbling at an inopportune moment for a spare card, it's always in the camera. On the 645D, there are two physical buttons on the left side of the camera to configure the memory slots. Hit a button, turn the rear thumb wheel and cycle through the JPEG, RAW, RAW+, Reserve and off options. No more silly fumbling through seven idiotic menu levels on the rear LCD. You can even put a Wifi card in SD2, turn it on in low resolution jpeg mode and shoot pseudo tethered to an Ipad if you wish.

All 645's have had attachment holes for both horizontal and vertical mounting plates. The 645D is no exception. L-brackets and there associated $180 cost are not needed.

Last but not the least a separate dedicated mirror lockup button. Is any one at Canon paying attention here. Nod, if you are awake please.

The Pixel Peeping Begins

Before I embarked on a true field test to assess the image quality of the 645D vis-a-vis its 35mm competitors, I decided to perform several of my standard evaluation tests that I use to compare the IQ of various cameras. Test one is a standard studio image that I use. It is shot in my basement under very controlled tungsten lighting conditions. It has a lot of fine detail, but the limited dynamic range of the scene does not push the envelope in terms of sensor dynamic range. Test two is a standard outdoor scene shot right off my front porch. It has lots of fine detail and a fairly wide dynamic range. It has white objects and sky in full sunlight as well as black objects sitting in the shade. By shooting both cameras at the same instant on two separate tripods, I can eliminate changing light conditions as a concern.

The results may be seen by clicking on thumbnails in the table below. Doing that will take you to 100% crops from two different sections of the images. When you get to that web page you may further click on a link to download full size jpeg's or in the case of the outdoor image, full size TIF's. All images were converted with daylight white balance and no sharpening in ACR. An USM sharpening filter of 250 0.3 1 was applied in Photoshop CS5. The images were framed to match in vertical size. This corresponds to the way I shoot. If you don't agree with my workflow, feel free to run your own tests. For the studio shot, the camera makers 100mm macro lens was used on each camera. For the outdoor shot the Canon 24-70mm lens was used on the 5Dmk2 and the Pentax 45mm-85mm lens was used on the 645D. The Canon shots were all taken an aperture of f8. The Pentax shots were all taken at an aperture of f11.

It's pretty obvious the 645D has more resolution, we all expected that. It also has at least 1 stop more dynamic range. Look at the black trash barrel in the outdoor shots. The 5Dmk2 shot has much more noise. This is a result of its smaller dynamic range. This agrees with some of the results that the DxO mark tests got when they analyzed the 5Dmk2 and 645D sensors. Beyond this, feel free to draw you own conclusions.


Studio Image

Outdoor Image
Outdoor thumb 1
Outdoor thumb2
Outdoor thumb2

Part 2 will be the field test of the 645D in varying real world conditions.

On to Part 2


All images & text unless otherwise indicated Copyright © WyoFOTO LLC 2000-2013