Michael's Pentax 645z Review

[michael]

We have just published my in-depth Pentax 645z review.

I have started this thread as a place for discussion about the review and as a place where I can answer any questions.

Michael

[david distefano]

thank you for your excellent article. by chance did you try out vintage hasselblad v system lenses and if so what were your results?

[michael]

No I haven't. I bought an adaptor ring on the thought that I might pick up one or two of the bargains that are out there, but haven't yet.

Michael

[tsjanik]

Michael:

Thanks for the entertaining and informative review.  As someone postponing the purchase of a 645Z (I have the 645D) while I consider the purchase of an A7r, I found your comments very useful.

Interesting that you are back to Pentax; when I first started visiting LuLa you were using a Pentax 67II and struggling with its 600mm f/4 lens.

Regards,

Tom

[Ken R]

We have just published my in-depth Pentax 645z review.

I have started this thread as a place for discussion about the review and as a place where I can answer any questions.

Michael

Thanks for posting! I was going to point out that there were some errors in the sensor size information but you seem to have corrected them quickly.

My impression of the 645D kinda applies to the 645z. It's a great body looking for lenses. But like it has been mentioned if what is available is good enough for your purposes then it is a superb camera otherwise an A7R (and the D810 to a slightly lesser degree) with it's ability to accept a huge range of superb lenses might be a better choice or the jump to a back and tech camera system if funds allow. Would love to see an actual system resolution comparison (camera lens combinations) between the 645z, the A7R and the D810 to see if the Pentax lenses (or which ones if any) take advantage of the extra (potential) sensor resolution of the 50mp sensor over the 36mp Sony sensor.

One aspect I would like more information on regarding the 645z is the service. I have been reading some horror stories regarding it with the 645D and now the 645z. From what has been posted one can expect to be 10 weeks without the camera if one has to send it in for repair. Can we expect this to change in the near future? Have you heard anything regarding this?

[michael]

I will be meeting with Pentax at Photokina in two weeks, and will asking specifically about service.

Michael

[JV]

This is obviously a valid question and 10 weeks is unacceptable IMO but I guess for most people a backup 645D at $5K could be an obvious choice.

Even 2 645Z bodies would still cost you $10K less than one Hasselblad body, not to mention Phase One.

[torger]

There's always disaster service happening to some people, even among companies like Phase One etc (where service is just as good or bad as your dealer).

But of course, if the default is to wait 10 weeks for a problem to be fixed, then there's an issue.

I think a self-contained camera like a Pentax 645z should not require more "dealer attention" than a Canon or Nikon DSLR, so if one likes the Phase One / Hasselblad dealer model I guess you won't find it for the Pentax. The traditional MF dealer model is however one reason gear costs you many times more than the Pentax, so I hope it's not a goal for them to get there.

[adam_k]

Hi Michael,
thanks for the review. It is interesting to see this after your Mirrorless vs dslr video that was recently published. Would you pickup the pentax 645Z when you KNOW you need to make a bigger print or do you find the quality any better then the sony a7R?

[michael]

Hi Michael,
thanks for the review. It is interesting to see this after your Mirrorless vs dslr video that was recently published. Would you pickup the pentax 645Z when you KNOW you need to make a bigger print or do you find the quality any better then the sony a7R?

No question, superior to the A7r, but the price is weight and bulk and cost.

Michael

[petermfiore]

Hi Michael,

I'm wondering, you say you often make exhibition sized prints. What size are you printing from the Pentax files?

Thanks,
Peter

PS   I bet their gorgeous.

[michael]

My gallery prints are usually 24x36" to 40x60". Depends on the image and what the file can manage.

Michael

[GarethC7]

Hi Michael

Great review, touched on everything I needed......almost

A few quick questions.

1. You note that the files from the 645Z are superior to the A7r (my only contender until 2 days ago), I can see DR and high ISO as well as just plain size, would you add anything else?

2. How would you say the A7r files might be considered superior to the 645Z?

3. Do you anticipate this living on a tripod or can it be handheld realistically? In Nick's early review he noted that the Hassy was slow to set up but it seems that the 645Z is a bit more nimble in terms of size, handling and menus?

Many thanks

G

[BernardLanguillier]

Congratulations on the new camera and thanks for the informative review!

Cheers,
Bernard

[fdisilvestro]

Michael,

In the review you mention using auto ISO up to ISO 12800. Since you are a raw shooter as far as I understand, and predicting an almost linear response regarding SNR vs ISO (what some call ISO less) I would suggest to not exceed ISO 1600. Most likely, if you check the raw files with a tool like RawDigger, those ISO's are achieved by multiplying the channels after a/d conversion.

This method might impair the use of JPEG previews but it will preserve highlights better without losing image quality

Two options: just set the shutter speed and aperture and treat ISO as if it were metadata (i do hope this will become normal in the future) or limit to ISO 1600 or even less and use exposure compensation.

Regards

[torger]

I think I've seen other cameras with similar Sony sensors to be ISO-less, ie there is no gain in increasing ISO rather than just pushing the base ISO file in post, so it's probably the same with the 645z.

However hunting exposure with exposure compensation or looking at near black JPEGs is not exactly improving the user experience. My own practical experience that if you have a high ISO image it's generally not that file you're going to tonemap to recover highlights and whatever, so the highlights can just as well be cut. In other words, the loss in user experience is not really worth it using the technique of shooting at low ISO all the time with varying degrees of under-exposure.

[eronald]

Typical "pro" tonemapping situation is interior architecture, where you want to show the view outside the windows, or at least not blow out the windows, but the customer's stuff is inside the room in the low-light zone.

I've been there and it is painstaking careful work, balancing the flash with daylight.  

I think the Pentax (and P and H Sony models) will pay for themselves quickly for these guys, since they save them a lot of strobe power, which is expensive to purchase, maintain, transport and takes time and effort to emplace.  

On the other hand, this is shift-lens work typically. I think Canon TSE adapters for Sony are going to sell very very well

Edmund

I think I've seen other cameras with similar Sony sensors to be ISO-less, ie there is no gain in increasing ISO rather than just pushing the base ISO file in post, so it's probably the same with the 645z.

However hunting exposure with exposure compensation or looking at near black JPEGs is not exactly improving the user experience. My own practical experience that if you have a high ISO image it's generally not that file you're going to tonemap to recover highlights and whatever, so the highlights can just as well be cut. In other words, the loss in user experience is not really worth it using the technique of shooting at low ISO all the time with varying degrees of under-exposure.

[patrickfransdesmet]

Michael,
looks great
i've played with the Z for a few hours
and must admit
for its price
jeez !!!

I remember, (I've worked for SONY 9 years as an engineer) 10 years ago, I talked to a Hasselblad representative in Belgium
I told him, the future would be a Haaselblad digital camera, but MIRRORLESS
I compared with 3CCD Betacam camera's, as SONY used to build

The guy walked with this idea to hasselblad sweden
Few weeks later, he came back and said, they laughed it away...

Should they've build a MFD camera, mirrorless, 10 years ago
They would have in a predominant position today

Now they'll loose it to lower priced, still DSLR like "Z" model ...

Laugh !

 

[dlacoutu]

Hello Michael,

While buying a 645z is way out of my league, I read your review with great interest. Having used various film and digital Pentaxes for the last 9 years, I was curious about how their (generally) excellent handling was transcribed in the MF digital era. Seems like they did it right again!

Well, anyway, I wrote here to comment on your ETTR remark. Having dabbled a little bit with that technique on their K DSLR line, the obvious setback that everyone quickly encounters is indeed the histogram being based on the JPG...

But (don't know if you stumbled on this on your investigation about the matter) there is a mean to get a near-real RAW histogram on the Pentaxes by using the UniWB trick!

Steps are easy:
- go to M mode, be sure to completely overexpose a picture (completely white pic).
- go to the white balance settings, custom WB, and use the shutter to snap a (fully white!) WB reference pic.
- go to the image settings, chose "muted" and customize it with low contrast and a slightly brighter setting (you can even use the advanced contrast setting to fine-tune the highlights and shadow contrasts).

By following these steps, the camera will be tricked by the custom WB and will apply a 1-1-1 ratio on the bayer matrix, instead of pushing up the reds and blues to balance with the doubled green photosites.

I voluntarily left out the exact image settings (contrast, brightness, etc), as it greatly depends on the sensor used. You have to play with them and compare resulting on-camera histograms with the actual RAW histogram (from Rawnalyze for instance)...

Only drawback : any JPG preview you get from the camera will be greenish and washed out, so forget about OOC JPGs...
But an easy way out of this is to assign these settings to a User custom mode only, so this way the camera will behave as usual in every mode except for this "UniWB" User mode...

Hope this helps...

[michael]

For those that believe that the 645z is "ISO-less", I was also curious about this and did some experiments last week.

It is to some extent, but setting the ISO does create a superior file to not doing so. Pentax is doing something in the A-D stage or afterward, because when I use the pseudo tone mapping controls in Lightroom (Highlights and Shadows) the results are not as good as setting the high ISO in camera and then using them. I've tested this at ISO 100, 1600 and 6400.

Reading their literature, talking to their people, and playing with files shows me that Pentax is doing a lot in terms of image manipulation in-camera, even to raw files, and that includes lens correction for all their lenses.

That's fine with me. The results are sterling.

As I wrote (and implied) in the review, I set the camera to TAV mode, manually set the appropriate aperture and shutter speed that the shot and conditions require, and let the camera set the ISO as appropriate, up to and including ISO 12,800. And only at 12,800 do I need to move the NR slider just a touch.

Frankly it's a revolutionary way of working. It makes hand-held landscape and nature shooting possible, and even on a tripod if the wind is blowing I can just bump the shutter speed until  the foliage is controlled, and still shoot at f/16 for DOF. With the P25 to the IQ180 I never would shoot above ISO 400 because of quality loss. Now I shoot to 6400 without thinking about it. That's a 4 stop advantage, and there's more in reserve.

Remarkable.

Michael