The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

Pentax 645Z vs A7RII IQ and bang for the buck

justalexander

New member
Thanks for the comment so far. I've managed to find some raw files to download and have to say I'm astonished by the quality of files from the 645Z!

If the profiles fully correct geometric distortion of the prime lenses based on focus distance and the zoom lenses based on focal length as well then I'm sold. I'm surprised though that no one else seems to have mentioned or discussed this. Again in something as simple as the attached shot, the residual moustache distortion from the Leica S 24mm lens is noticeable and disturbing.

Can anyone with any experience with the following lenses provide any information on how good the lens profiles are? 25, 28-45, 45-85 FA, 55, 75, 90, 120. I know everyone jokes about shooting brick walls to test lenses but as an interiors and architecture photographer I do strangely do find myself shooting brick walls!

Thanks
 

Attachments

CSP

New member
The A7rii is certainly an interesting camera with a high possibility to rip a decent share of the MF market but all the time the sensor is 135 it'll miss a certain look and feel to the image.
i have seen impressive photography done for movies by dop´s like michael ballhaus shot on the rather small 35mm cine format so maybe the format is not too important at all...
 

Stuart Richardson

Active member
Thanks for the comment so far. I've managed to find some raw files to download and have to say I'm astonished by the quality of files from the 645Z!

If the profiles fully correct geometric distortion of the prime lenses based on focus distance and the zoom lenses based on focal length as well then I'm sold. I'm surprised though that no one else seems to have mentioned or discussed this. Again in something as simple as the attached shot, the residual moustache distortion from the Leica S 24mm lens is noticeable and disturbing.

Can anyone with any experience with the following lenses provide any information on how good the lens profiles are? 25, 28-45, 45-85 FA, 55, 75, 90, 120. I know everyone jokes about shooting brick walls to test lenses but as an interiors and architecture photographer I do strangely do find myself shooting brick walls!

Thanks
Hi Alexander,
Have you considered trying the Adobe Lens Correction profile generation tool? It seems as though your requirements are incredibly stringent in this regard, so I don't think it is too likely that you will find many manufacturers who have provided software corrections to the degree you are looking for. http://www.adobe.com/support/downloads/detail.jsp?ftpID=5489
As a landscape photographer, I look at your attached photo and see a very minor distortion in the table at front, and given that this is one of the very widest lenses available in medium format, and a retrofocal SLR lens, I would be pretty impressed by its performance. In my own work, I often turn off the lens correction in the S lenses, as I find that the distortion is so minimal that the loss in sharpness and increase in digital artifacts* is not worth the correction.

I have only seen this one picture from you demonstrating the issue...is it equally problematic in other compositions?
In any case, I would think that since this is your full time job, it would probably benefit you more to work with a camera that fits your needs on a shoot (like the Leica, Pentax or Hasselblad), and then accept that you might have to do some post processing or profiling work yourself to get it to meet your exact needs for output. If you make the lens profiles yourself, you probably have a bit more flexibility to make them correct things exactly how you want. Or perhaps you will have better luck with the Pentax! My guess is that their profiles will be fairly similar to Leica's, since they are also generated by Adobe.

*I have sometimes found that the "remove chromatic aberration" options in lightroom can do more harm than good in certain high contrast lighting situations. The CA is so low in the S lenses that I generally keep the lens profiles off by default and only turn them on when needed.
 

JohnBrew

Active member
That is quite a deal!!
Graham, only if you must have the Leaf back. If you buy the Actus DB+ piece parts, eliminate the kit back and buy a CFV-50c (essentially the same as the Leaf) you would save $4K. Now THAT would be a deal.
John
PS. I hope you have some luck in getting your equipment back. I'd try a classified offering a reward for "return" of your lost gear, no questions asked.
 

justalexander

New member
Seems like a pretty good solution. But I've been looking for LH and RH connectors for some time. A much smaller market here. Sony came to their senses and provided a jigger which hls the cord in place, but the connector themselves are still flimsy requiring disconnection/reconnection tight at the most inopportune time!


@justalxander

i never experienced connection problems with the sony but i use right/left angle connectors like http://www.amazon.com/StarTech-com-Micro-USB-Cable-UUSBHAUB3RA/dp/B001AR4NC8
 

turtle

New member
On the subject of the 120mm macro, I agree... its like most older macro lenses: can be great at distance, but needs more stopping down than a non-macro. My newly acquired 150mm f2.8 eats the macro for breakfast at wide apertures for distant subjects and remains superior at f11.

The 150mm f2.8 FA has a bit of a glow wide open, but still has excellent cross frame resolution, but by f4 its pretty well at the top of its game already. By f5.6-8 there is a very slight improvement in corners and edges, but its already close to perfect at f4. Its an amazing lens and I was quite shocked how good it it, as I was with my new (used) FA 80-160. At the long end it is supposed to be a bit weaker. To all intents and purposes, mine keeps up with the 150mm prime at f8-11.

A stroke of luck saw me pick up (all used) a 80-160 FA from Germany, a 150mm f2.8 from a UK store and a 45-85 FA (yet to arrive) from the UK within a week, all at brilliant prices. These 2 x zooms are the way to go.... and they perform noticeably better than any of the zooms for the FE system to day. I'll be posting reviews on my blog in due course. V impressed!
 

justalexander

New member
Hi Stuart, I appreciate your time in responding.

I got spoilt using the Hasselblad because Phocus has over 200,000 profiles for every lens at every focal length at every aperture at every focus distance. Without the corrections the lenses are as crooked as question marks but with 1 click, geometric distortion is COMPLETELY removed. I spoke directly with the sales manager of the Phase One XF from Denmark and was told that not even Phase One/Capture One has this level of correction.

Unfortunately I don't think Hasselblad ever expected digital backs to become so large because 50MP is pushing the limits of their lenses. To be fair though, no manufacturer expected this level of resolution. Leica had to develop the S range of glass from scratch. Zeiss have only just announced their third Otus lens and Schneider are in the process of redeveloping their range for Phase One.

The problem is most obvious when shooting objects front on, which as an interiors and architecture photographer happens regularly. If I shot landscapes it wouldnt be a problem because the only perfectly straight line I can think of in nature is the horizon, and without another perfectly straight line either parallel or perpendicular to the horizon it's difficult to notice curvature across the entire frame.

It takes lens designers years of research and a tonne of money to create a lens yet I believe a computer can generate a perfect (at least theoretical) lens profile in minutes using the simple lens cross section schematic that manufacturers publish in their lens brochures. It’s probably the least labor/money intensive task to perform in lens design. Every lens designer already has a profile so why not do it properly? The Leica Q relies heavily on lens correction Even Alpa created lens profiles for the legendary range of Rodenstock and Schneider used on its cameras.

I've tried Adobes lens profiler but the general consensus is that its more miss than hit. Possible if you only ever shoot 1 lens at one aperture at 1 focal distance but to generate the 200,000 profiles Hasselblad have for their lenses would require a lifetime for a human but mere minutes for a computer. The problem might simply be that lens profiles used by Adobe aren't able to carry the amount of data for a a full lens correction.

Either way, I'm contacting the local Pentax rep today to see if I can get my hands on a demo. The 645Z certainly looks like it provides a HUGE bang for its buck!
 
Last edited:

jerome_m

Member
Unfortunately I don't think Hasselblad ever expected digital backs to become so large because 50MP is pushing the limits of their lenses.
Hasselblad has had a 200 mpix camera for some years now (multishot) and the people using it do not complain that the lenses are not fit to that resolution.
 

justalexander

New member
Hasselblad has had a 200 mpix camera for some years now (multishot) and the people using it do not complain that the lenses are not fit to that resolution.
I'm glad to hear that Jerome but do you have any personal experience using the 200MP multi shot?

I've shot with a H3DII 22MP for the last 10 years (with 28mm, 35mm, 50mm, 80mm and 50-110mm lenses) and absolutely love the quality of its files. It recently broke and I've been using a Sony A7RII while I look for another medium format system. I've just spent the past week shooting with the H5D50c and recently tested the Phase One XF and Leica S. In my opinion/experience I believe the Hasselblad lenses aren't up to scratch for a 50MP back.

In support of my opinion, Hasselblad haven't updated their lenses (except the 50mm) since their release in 2002 (13 years ago!) at a time when Nikon and Canon had only just released 6MP cameras and Hasselblad hadn't even contemplated a digital solution. Now every 35mm manufacturer is scrambling to update their lens range to cope with the increasing MP count. Leica had to design the S range of lenses from scratch, Zeiss are releasing new ranges of lenses designed specifically for the demands of digital sensors and Schneider are redesigning their lenses for Phase One.

I was working with the 16MP Sinar multi shot back in 2002 but these backs were used on tech camera with large format lenses. (large format symmetrical design lenses are generally considered to be sharper than retrofocal designs required by slur's) The Hasselblad 200MP requires 6 shots to produce its file.

Michael Reichmann did a comparison between the Hasselblad H3D 50 II multishot and Phase One P65+/645AF in 2009 and even then concluded that in single shot mode the P65+ was superior and in multshot mode the H3D only just managed to beat it.

If you have some 200MP multishot files I'd love to see them!
 
Last edited:

torger

Active member
Michael Reichmann did a comparison between the Hasselblad H3D 50 II multishot and Phase One P65+/645AF in 2009 and even then concluded that in single shot mode the P65+ was vastly superior and in multshot mode the H3D only just managed to beat the P65+.
While LuLa has great reviews concerning usability etc, I don't trust them much when it comes to pure technical image quality analysis. They've had some strange claims through the years, such as DSLRs have 6-7 stop DR and MFDBs 12-13 stops. Multishot is much about getting rid of aliasing artifacts and I think you need to appreciate that specifically to like it.

In the D800e review if I remember correctly mr Reichmann claimed that there is no aliasing issues despite no moire filter and if you think that you probably are not in position to appreciate multishot.
 

justalexander

New member
In the D800e review if I remember correctly mr Reichmann claimed that there is no aliasing issues despite no moire filter and if you think that you probably are not in position to appreciate multishot.
I've been working with multi shot technology since its inception (over 13 years) including working closely with the Sinar importers. I've used Sinar and Leaf multi shot backs on rail/tech cameras as well as the Sinarcam which had lens boards for 35mm and medium format lenses. I believe I have sufficient knowledge of multi shot technology.

Not only is multi shot designed to get rid of aliasing artefacts (moire) by capturing red, green and blue values at each pixel (overcoming the design limitations of bayer designs) it gains resolution by shifting the sensor by half a pixel for 2 extra shots to capture information that would ordinarily fall between each pixel. Hasselblad multi shot takes 6 shots which differs from Sinar's backs which took 4 or 16 shots in multi shot mode. Only by combining these 2 techniques to overcome the limitations in the bayer design can it produce higher res files.

Physics dictates that a multi shot back will produce a sharper image than a single shot back using the same lens but the same laws of physics dictate that some digital backs out resolve some lens designs. I've compared the same 50MP sensor from Hasselblad and Phase One where the key differentiator is the lens and I personally believe Hasselblad's 13 yr old Fuji designed lenses cannot match Sony's state of the art 50MP cmos sensor or Schneider's new lens designs. If you look for Capture Integrations comparison of the new Schneider 35mmLS with the old Phase One 35mm lens you'll clearly see why 13 year old lens designs might need updating.

Regardless, I can discuss both the engineering of multi shot technology and also my personal experience using the H3DII 22MP, H5D50c, Sony A7RII, Leica S and Phase One in back to back use over the last month... but this thread is intended for people wanting to discuss Pentax 645Z, the A7RII and bang for buck!
 

jerome_m

Member
I'm glad to hear that Jerome but do you have any personal experience using the 200MP multi shot?
No, I use an H4D-50. But I gather that we would know it if lenses were not usable on the multishot backs.

In support of my opinion, Hasselblad haven't updated their lenses (except the 50mm) since their release in 2002 (13 years ago!)

Many lenses are more recent than 2002:
HCD 28 (2006)
HCD 35-90 (2008)
HC 50-II (2010)
HC 120-II (2010) and
HCD 24 (2012).
 
Can anyone with any experience with the following lenses provide any information on how good the lens profiles are? 25, 28-45, 45-85 FA, 55, 75, 90, 120. I know everyone jokes about shooting brick walls to test lenses but as an interiors and architecture photographer I do strangely do find myself shooting brick walls!

Thanks
Of the ones you've mentioned I only have the 55 & 120mm. The 55mm is decently sharp, but the outer parts of the image circle suffers from lots of plane curvature, which many people immediately react to as being soft. I suppose that effectively it may as well be so.

Here's an image I shot at f/8 and the red circle marks where the building stops being sharp; the transition is fairly obvious up close.



I can't say much about the 120mm because I seem to have a bad copy of it, as it's considerably less sharp than my 150mm at any aperture; it's still fine for the macro stuff I do, so I'm not in a hurry to replace it.
 

justalexander

New member
Of the ones you've mentioned I only have the 55 & 120mm. The 55mm is decently sharp, but the outer parts of the image circle suffers from lots of plane curvature, which many people immediately react to as being soft. I suppose that effectively it may as well be so.

Here's an image I shot at f/8 and the red circle marks where the building stops being sharp; the transition is fairly obvious up close.

I can't say much about the 120mm because I seem to have a bad copy of it, as it's considerably less sharp than my 150mm at any aperture; it's still fine for the macro stuff I do, so I'm not in a hurry to replace it.

Thanks, thats much appreciated. That's exactly the kind of subject matter I'm likely to be shooting so it's very interesting to know.
 
Thanks, thats much appreciated. That's exactly the kind of subject matter I'm likely to be shooting so it's very interesting to know.
And here's a 100% crop of the far left detail just outside of the red circle, followed by the second one just inside of it.
I was shooting freehand, so it's not as overall sharp as it could have been, but you can still tell the difference.



The ground was sharp out to the corners which is why I believe this to be curvature, maybe if I had shot at f/14 or even f/22 I could have alleviated this, but had no tripod with me at the time. You can always square-crop your images :p
 

justalexander

New member
No, I use an H4D-50. But I gather that we would know it if lenses were not usable on the multishot backs.

Many lenses are more recent than 2002:
HCD 28 (2006)
HCD 35-90 (2008)
HC 50-II (2010)
HC 120-II (2010) and
HCD 24 (2012).

Do you wish to contribute something RELEVANT to this thread Jerome or just sledge me for taking the time to provide other readers with my personal EXPERIENCE based on testing numerous camera systems BACK TO BACK over the last month? I am genuinely interested in your personal opinion and experience, in fact that's what everyone is here for, but please save everyone's time by not sledging me based on mine or posting pointless off topic-comments based only on what you GATHER we would know...

I've spent $75,000 on Hasselblad equipment so far and have LOVED every minute shooting with it, resisting the urge to swap brands on numerous occasions despite very poor support for the brand in Australia so I hold no grudge against the camera system. But before I spend ANOTHER $40,000 on the H5D50c I would like to hear about other peoples personal EXPERIENCE whether their might be a camera system with more BANG FOR THE BUCK than the Hasselblad, which in this case as the thread clearly says is the Pentax 645Z and A7RII.

I've recently spent $10,000 on an A7RII and now just wondering whether its worth putting together a 645Z system for $20,000 which is just 1/2 the price of a new back alone. In my personal EXPERIENCE assisting fashion photographers, Pentax was often preferred for its beautiful rendition of skin tones and bokeh and I'm wondering whether this is still the case.

Kolo-Pikker has taken the time to provide an example (including enlargements) of the 55mm (very interesting by the way and thank you) and it appears it might indeed still be perfect for portraiture and fashion photographers but less so for architecture and interiors. So what is an asset for one photographer is a liability for another.

Rhern213 also took the time to show readers how good the 120mm Macro is on the 645Z while ErikKaffehr provided a polite (and relevant) reply in response. Rhern213 (and if I read his post correctly, and to my astonishment) showed how good the 75mm is on the Pentax compared to the 55mm on the A7RII because in my personal EXPERIENCE owning the 55mm and A7RII it's a stellar performer so no mean feat for the Pentax to match let alone better it! (again many thanks for the example).

So now that we've got that unpleasantness out of the way please enlighten me on your experience with either the Pentax 645Z and/or A7RII...
 

justalexander

New member
And here's a 100% crop of the far left detail just outside of the red circle, followed by the second one just inside of it.
I was shooting freehand, so it's not as overall sharp as it could have been, but you can still tell the difference.



The ground was sharp out to the corners which is why I believe this to be curvature, maybe if I had shot at f/14 or even f/22 I could have alleviated this, but had no tripod with me at the time. You can always square-crop your images :p

I assisted a lot of fashion photographers and their preferred brand was Pentax. Despite being temperamental and often having shutter problems requiring as many as 2 back up bodies for a shoot (at least in the case of the Pentax 67) the lenses produced the most beautiful skin tones and bokeh. Is the field curvature of the 55mm a common trait of Pentax lenses and therefore an explanation for Pentax popularity amongst fashion photographers???
 
Top