First look at Pentax 645z

Big kudos to Dodd’s Camera in Chicago for having a Pentax 645z in stock for me. Pentax packaged the camera in a beautiful thin gray box enclosed within another thicker gray box. And in the gray box is another box, but in black. The packaging is impeccable. I am going to make sure the box is kept safe from my cat. Anyway the 645Z which I will call the Z, uses the same batteries from the old D. So it was just a matter of inserting one of the many batteries I already own from the D into the Z and off I went shooting.

645z boxes

First thing you notice is that the Z is lighter than the D. The D feels like a brick compared to the Z although it uses the same magnesium alloy body. Gone is the loud “clang” shutter noise of the D and is replaced by a rolling shutter which is highly muted. It rolls twice when in live-view and once when live-view is turned off just like how any dslr with live-view works. This is so much better than the shutter of the original D which at times would make a high frequency squeal and made you think something was wrong with the camera (many people have said it could be a cold temperature thing) .

It takes about five seconds to fully write a raw file plus jpg on the Z whereas the D took approx. eight seconds. This is on a 30mb/sec sd card. Five seconds sounds like a long time but to be fair, the Z has a 3 shot buffer design so you can keep shooting for three frames per second. The buffer is only 3 frames so after one second it slows to a hault. Also when you want to preview the shots you will be reminded of the slow operation inherited from the original D. Yes you do have to wait, just like the D, to show the pictures to your subject and sometimes for an annoyingly long time (like 10 seconds if shooting back-to-back pics). But overall this is a major improvement to the speed of the camera and makes it more like a dslr and 3 frames per second is unheard of in the medium format world.

Live-view is a nice addition however the titling screen primarily favors horizontal type shots as it only tilts outward on a fixed axis. I primarily shoot people so my personal preference is to shoot vertical. Anyway I don’t really use live-view as I always look through the viewfinder and focus manually. But this is definelty good news for landscape photographers.

The low noise floor, high iso capability of this camera is the main reason I bought the Z. The high iso jump is like going from a Canon 1Ds mark II to a 1DX. The high iso jump also means that you can use Pentax’s line of 4.5 and 5.6 lenses during the day without carrying a tripod. Gone are the days of using my 80-160/4.5 lens at iso1600 on the D.

The picture to your right was lit by an outdoor tungsten lamp nearing darkness at 1/40 sec with a 75mm lens at iso 25600. The muted color mode works really well with this subject. I put an iso3200 next to the picture to show that degradation is minimal.


When using the D, I was always aware of my iso setting and try to stay between 200-800. The default on Z’s ISO auto setting is now from 100-3200. Of course you can change that and go as high as you want but this leads me to think it is Pentax’s threshold for high-quality print images. However images are still good for websize stuff at 6400 and 12800. By 25600, images start to soften up a bit but they are still usable for web. I think this is where my threshold ends because after that it gets really noisy and colors fade very quickly at 50k, 100k, and 200k. I will gladly shoot the Z up to 25600 without hesitation and this is with Noise Reduction turned off.

Pentax Digital Utiliy Sofware 5 is a big improvement especially in the user interface. They made it more intuitive and easier to use. Everything is still there as far as functionality goes. I did not see anything new except support for the new color mode – “Cross Processing”. The browser is much faster and the laboratory makes much more sense. Write times to jpg from raw seem about the same speed as version 4 — acceptable but a little slow. I use only PEF raw’s for processing so every picture you see is done through Pentax’s software.

In my next post I will go over in detail the difference between the D and Z at iso 200.

In the meantime I was happy to get a nice “medium format” shot of this young college girl. The light was perfect and the 75mm wide-open is my favorite setting for this lens.

pentax 645z