645Z Going wild!

[D&A]

Dave, thanks so much for your work in testing out the various lenses for the Pentax and also for your comments here.

No, this is not my first trip and hopefully not the last either

Do you think the 45-85 is a better choice than the 55 - I ask from the weight point of view and some reports that the zoom is soft at longer end.

I think as my experience with the 645 grows I will become more confident in its use as my primary camera, but I am a bit far from that right now. So the Canon system will definitely see quite a bit of use on this trip.

Pradeep

Again becuase I am at work and on my cell phone at the moment, my response will be brief. The 55mm is a good to very good lens but I found sample to sample variation and many have side's and corners that lag behind central resolution until well stopped down. Some had edges that never quite caught up to center sharpness. The lens is WR and is certainly light enough and focuses quite fast but personally its not my very favorite.

By contrast a excellent sample of the 45-85 has turned out a most useful lens amd optically very good to excellent especially between 45-65mm even when shot wide open. At these more open apertures, the 85mm focal length is softer in comparison but still decent and once stopped down a bit more comes close to the rest of the zoom range. All this is predicated on both a good sample as well as adjusting given lens for front/back focusing thru the 645z menu. (Fine tuning lens). This is important especially with this lens.

Bigger and considerably heavier than the 55mm and not WR, its a tradeoff but personally if it comes down to optics, I'd reach for the zoom. Many of my ley pages for professional jobs and very large format prints were taken with this lens.

Keep in mind I pixel peek at 100% of the entire frame and also often print crops of what would be very large prints before determining performance of a given lens.

Dave (D&A)

 

[Kolor-Pikker]

Dave
Have you summarized any of the latest 645 lenses somewhere that might help me gain more knowledge. As a matter of fact the older lenses could be interest also. I a new 645Z user this becomes invaluable, TIA

Lou

Here's my take on the lenses I've used.

55mm f/2.8 - pretty good lens overall, but the far corners are soft, even at f11. Everyone should have this lens, it's usable for just about any subject matter.

105mm f2.4 - Pentax 6x7 adapted lens, mainly used for portraits and the way it renders the image, which can be a love it or hate it affair.. I don't really like the way the bokeh looks TBH.

120mm f/4 Macro - sharp, but heavy and slow... you can feel the lens recoil as it autofocuses. It's great when shooting on a tripod, but I feel the 150mm is much better for hand held use.

150mm f/2.8 - awesome portrait lens, it starts off slightly soft but sharpens up tremendously by f/5.6, and f/8~11 it's easily as good as the macro. Focus is super fast, and the lens is fairly small and light.

All of these lenses feature green/magenta LoCA around high contrast areas, which is a worrying pattern I see with the Pentax glass. Maybe the 90, 28-45 and 25 are better corrected for digital sensors, but as it is you'll have to do a lot of CA correcting in Lightroom.

 

[D&A]

Joe

I now realize I saw this excellent lens test results. I was hoping for a follow-up with the newer 645 lenses which are of the sealed variety like the 25, 28-45. 55 and 90 macro.

Also I just wonder if many of the original comments by D&A back in 2012 still apply when using the 645Z or there is now room to fine tune comment based on 645Z usage.

Lou, you may not have aeen my comments a few posts above regarding my testing of all the newer Pentax lenses. In addition I tested almost the whole range of Pentax 645 af lenses both old and new on a loaner 645z. There were far fewer samples of most lenses tested with the 645z than with the original test with 645D but results were essentially the same so I would feel confident on the original part I testing if applied to the 645z. I just wish enough time would open up for me to write another comprehensice report. I moved not all that long ago and still have a household to unpack. I keep finding a treasure trove of photo related items I never knew I had. Even came across my wonderful Bessler enlarger mounted on high school AV cart so I can make any room into a messy darkroom again. What fun!...LOL!

Dave (D&A)

 

[D&A]

Here's my take on the lenses I've used.

55mm f/2.8 - pretty good lens overall, but the far corners are soft, even at f11. Everyone should have this lens, it's usable for just about any subject matter.

105mm f2.4 - Pentax 6x7 adapted lens, mainly used for portraits and the way it renders the image, which can be a love it or hate it affair.. I don't really like the way the bokeh looks TBH.

120mm f/4 Macro - sharp, but heavy and slow... you can feel the lens recoil as it autofocuses. It's great when shooting on a tripod, but I feel the 150mm is much better for hand held use.

150mm f/2.8 - awesome portrait lens, it starts off slightly soft but sharpens up tremendously by f/5.6, and f/8~11 it's easily as good as the macro. Focus is super fast, and the lens is fairly small and light.

All of these lenses feature green/magenta LoCA around high contrast areas, which is a worrying pattern I see with the Pentax glass. Maybe the 90, 28-45 and 25 are better corrected for digital sensors, but as it is you'll have to do a lot of CA correcting in Lightroom.

Spot on regatding your findings with the 55, 120 macro and 150 (what I like to also refer to as a portrait lens). Even though it sharpens up dramatically when stopped down, it drawers a delicate image, almost pastel like which is also lovely for certain landscapes. Dramtaically different than the 120 macro.

By the way, the macro as expected is optomized for closer range subjects and when compared to the best out there, is a bit soft on the sides and corners when shot at infinity, especially when thiese areas of the frame are compared against the center portion.

One last thing. The 25mm, both older and newer versions often suffer from quite high levels of LoCA..although some differences between the two in this regard exists. Depends on subject and lighting of course.

Dave (D&A)

 

[Shashin]

I have the A 120 macro, tack sharp at infinity. I have a 44" x 120" landscape print from my 120mm that was shot at f/8 that is beautiful. It is the sharpest lens I know of for the 645D/Z. Being optimized for close focus does not follow that a lens is not excellent at infinity. It is more true the other way around.

The 120 mm is also really great wide open. I have posted a number of images here with the 120 at f /4. The lens is amazingly crisp at the focal plane and beautifully diffuse away from it. I use the 120 very often handheld and never had a problem.

 

[D&A]

Hi Will,

I know it wasn't intentional but my previous words about the 120 macro (specifically the FA version), were a bit taken out of context. I've always written that the lens is the sharpest lens of all the original legacy Pentax 645 FA lenses. No question about it. I also know for a favt that it is optomized for close focusing range as.most dedicated 1:1 macro lenses are.but that doesn't mean they aren't sharp at infinity (which the 120 is), but if there is a foxusing distance where a bit has to give with that lens, its at infinity in all samples I tested. I

I had poster size prints for a client made with that lens of a shot taken of a subject near infinity and it was sharp edge to edge and I also believe it was taken around f8 or f9.5. Yet as I specifically stated in my post above, I said it given up a bit at the edges and xorners at infinity when compared with the best and it does. I did a two day head to head with it against the Leica S 120 macro which only goes down to 1:2 and found out aftet a letter to Germany, that the Leica S 120 macro is optomized for a distance of approx 15 feet.

When I compared both lenses simultaniously on their respective bodies at three different distances, they resolved virtually the same at close range and also at a distance of approx 25 feet. Yet at infinity, one could readily see the somewhat but definite superiority of the Leica in the central portion of the frame (at infinity) and there was no contest if comparing sharpness away from central portion of the frame. Leica won hands down regardless of f stop.

When looking at the Pentax image alone, the infinity images look sharp edge to edge but only when the Leica is added to the comparison, is the relative weakness of the Pentax at infinity seen. The key word is relative. I stand by that days testing as it was done not only for myself but also in a more comprehesive shooting comparision and ultimately prints that were requested during introduction of a particular Leica S body.

In any case we both can agree that the Pentax 120 macro is certainly one of the finest of thr Pentax 645 lenses.

Dave (D&A)

 

[Shashin]

Hi Will,

I know it wasn't intentional but my previous words about the 120 macro (specifically the FA version), were a bit taken out of context. I've always written that the lens is the sharpest lens of all the original legacy Pentax 645 FA lenses. No question about it. I also know for a favt that it is optomized for close focusing range as.most dedicated 1:1 macro lenses are.but that doesn't mean they aren't sharp at infinity (which the 120 is), but if there is a foxusing distance where a bit has to give with that lens, its at infinity in all samples I tested. I

I had poster size prints for a client made with that lens of a shot taken of a subject near infinity and it was sharp edge to edge and I also believe it was taken around f8 or f9.5. Yet as I specifically stated in my post above, I said it given up a bit at the edges and xorners at infinity when compared with the best and it does. I did a two day head to head with it against the Leica S 120 macro which only goes down to 1:2 and found out aftet a letter to Germany, that the Leica S 120 macro is optomized for a distance of approx 15 feet.

When I compared both lenses simultaniously on their respective bodies at three different distances, they resolved virtually the same at close range and also at a distance of approx 25 feet. Yet at infinity, one could readily see the somewhat but definite superiority of the Leica in the central portion of the frame (at infinity) and there was no contest if comparing sharpness away from central portion of the frame. Leica won hands down regardless of f stop.

When looking at the Pentax image alone, the infinity images look sharp edge to edge but only when the Leica is added to the comparison, is the relative weakness of the Pentax at infinity seen. The key word is relative. I stand by that days testing as it was done not only for myself but also in a more comprehesive shooting comparision and ultimately prints that were requested during introduction of a particular Leica S body.

In any case we both can agree that the Pentax 120 macro is certainly one of the finest Pentax 645 lenses.

Dave (D&A)

Dang, you mean my $300 A 120mm Macro was beaten out by some $6,400 German knock off.

 

[D&A]

Dang, you mean my $300 A 120mm Macro was beaten out by some $6,400 German knock off.

I'm afraid so Will but so was my FA 120 lens . I think we need to grab a good glass of beer and drown our misfortune....LOL.

I actually never really took notice of the relative and slightly lower performance at infinity with the Pentax 120 (especially in the outer zones of the image) until that days comparison.

Dave (D&A)

 

[Kolor-Pikker]

I'll have to agree with Dave, the 120mm vs. 150mm extreme corners at f/8 to f/11, the 150 is just a bit sharper/more even across the frame.
I still have yet to do my sanity check by shooting a real-world subject at infinity using that tilted camera trick, maybe I'll do it today, but weather has been terrible. I need to know whether my 120/150 are in line with what others have, as Pentax lenses are known to have a lot of sample variance.

Edit: I think I must have a really terrible 120mm sample, the corners on the 150mm are better at nearly every aperture than the macro: https://dl.dropboxusercontent.com/u/41183616/test.jpg

 

[D&A]

I'll have to agree with Dave, the 120mm vs. 150mm extreme corners at f/8 to f/11, the 150 is just a bit sharper/more even across the frame.
I still have yet to do my sanity check by shooting a real-world subject at infinity using that tilted camera trick, maybe I'll do it today, but weather has been terrible. I need to know whether my 120/150 are in line with what others have, as Pentax lenses are known to have a lot of sample variance.

Edit: I think I must have a really terrible 120mm sample, the corners on the 150mm are better at nearly every aperture than the macro: https://dl.dropboxusercontent.com/u/41183616/test.jpg

Thanks for your observations! Again as I previously mentioned, its all relative. The Pentax 120mm was designed 1st and formost as a 1:1 true macro lens and thus its strongest performance is in closest subject distance range for it was optimized for. Infinity is furthest from this range of course.

In 35mm cameras, I have a Sigma 150mm macro which also goes down to 1:1 and is as exceptional optically as the Pentax. It too does exceedingly well at all distances but it can be readily seen that at infinity and away from the center of the frame, sides/edges and corners are definitely lower in resolution. Its still has good detail there like the Pentax 120, but simply this distance doesn't play to its strength.

In contrast, The Leica S 120 lens is a close focusing lens (macro only goes down to 1:2), which is significantly different than a 1:1 macro, and thus its easier for it to be optically to be stronger at longer distances (which it is), especially if lens was not optimized for min distance in it 1:2 close focusing range.

Although I cannot speak for your given sample of 120 macro, it may be just fine...even in what you are observing at infinity....unless you find another sample that seems to do better at infinity subject distances.

Oh I too did the tilt/angle test at infinity the days I was testing the Pentax vs Leica S macros...the actual flat field building at distance was a beautiful early 20th century structure with lots of ornate detail...somethings rarely seen in todays modern urban landscape.

Dave (D&A)

 

[algrove]

Thank you very much Joe, greatly appreciated.. Lou, you'll notice none of the new lenses like your 25mm, 28-45 zoom, 90mm macro amd a few older lenses like the manual focus 600 f5.6 are included in the posted results. I've tested multiple samples of these lenses too but since the intial posted report (Part I) simply haven't had time to write up Part II. Something always comes up to get in the way. I have though provided general feedback on each when asked.

Dave (D&A)

Dave
Good stuff and most appreciated. In a few words can you please summarize your 645Z fingings with the 28-45 and 90 macro? I see your 45-85 analysis. Just got one used and will try to calibrate for a trip in 2 weeks. From what I read, you seem to calibrate each and every lens on the 645Z. I must be more thorough. Thanks for all your help.
Lou

 

[D&A]

Dave
Good stuff and most appreciated. In a few words can you please summarize your 645Z fingings with the 28-45 and 90 macro? I see your 45-85 analysis. Just got one used and will try to calibrate for a trip in 2 weeks. From what I read, you seem to calibrate each and every lens on the 645Z. I must be more thorough. Thanks for all your help.
Lou

Lou, thank you for your kind words, its very much appreciated. Its all about sharing and I've derived so much info from yourself and many others in a great many areas.

As usual I am at work and currently on my cell phone so for the time being what I'll do is cut and paste a bit of info regarding the 28-45 zoom you asked about from am email I sent to a forum member recently. I'll quickly make a few changes to shat I wrote him. Its quite general and lacks the specifics of my in depth testing of this lens but until I write up a comprehensive report, it will give you a head start on what to expect. Please keep in mind details like specific f stop performance each at three specific distances as such was not discussed nor in depth observations about field curavture or distortion to any great degree. OK, here is what I basically wrote in that email:

"One of the last major in-depth lens testing with 645 lenses I did was a direct head to head comparison of the Pentax 25mm vs. the 28-45 zoom you mentioned....with the zoom set at 28mm of course and then tested the zoom alone throughout its range.

At 25mm, the zoom is a sharper lens at the more open apertures, especially in the outer zones away from the center. The center resolution between the two are domewhat close...elsewhere less so (zoom sharper as mentioned). There is more field curvature and distortion in the zoom as expected in an overcorrected lens (which gives it its advanatge in sharpness), but for landscape work, its mostly kept in check in the so called reasonable range and is easily correctable in post processing.*

The single focal length 25mm lens is often notorious for CA. Pentax was aware of this and redesigned the 25mm mid run and one of the things they did is to extend the hood over the front element (this now for a cropped sensor only) but it only had a mild effect in reducing it. The zoom exhibits quite a bit less in situations that trigger CA.

The 25mm is a moderately hefty lens but the zoom is downright big and heavy and that in itself can be a big disadvanatage for some unless you are mostly using it tripod mounted or don't mind the extra weight and size for transport along with other gear.

The zoom's range of course is ideal and matches well with the 45-85 zoom."

Dave (D&A)

 

[algrove]

Dave
I find this encouraging about the 28-45. Pehaps the extra 3mm the 25 gives me on long distance trips is not worth the extra weight or should I say opens up room for a 45-85.

Have you had any luck with the new 90 macro? For me it seems to fill a nice gap especially if the 45-85 zoom is to be less used above 65-70mm. My question centers at this point on landscape use, but generally all uses.

 

[D&A]

Hi Lou,

The short answer is if one puts aside size and weight differences between the 25mm and 28-45mm zoom, in most all cases I'd much prefer the zoom vs. the 25mm. Their are exceptions though (seems there always is) and if one needed the lens that had lower distortion charateristics on the fly (say for a client to view on the spot), then the 25mm might be preferable. Same with say interior shots where the widest possible of angle of view was necessary...that 3mm might be important. For most other situations, the versitilty of the zoom is hard to ignor (again aside for the additional weight and size).

Regarding the 90mm, there is no question that optically it is a superb lens, especially after having examined my test results, yet for me personally its a lens thats I often had trouble justifying. Its big, and relatively bulky for a single focal length 90mm medium format lens and is neither a true macro (goes down to 1:2 if I recall), and I wasn't enamored with it as a portrait lens. Too sharp for the latter. Although it would result in two lenses, I prefer having the 120mm macro and 150mm for portrait work. The latter is so light I often think they left out some of the elements .

Of course all my comments haven't taken into account the vibration reduction capabilities and advanatges of the new lenses...which contributes greatly to their bulk and weight. Its a tradeoff in some ways.

Dave (D&A).

 

[algrove]

Your "too sharp" comment regarding the 90 macro reminds me of the old Hasselblad V 100/3.5 lens that many fashion/portrait photograhers complained was too sharp for their needs and that was like 30+ years ago.

 

[D&A]

Your "too sharp" comment regarding the 90 macro reminds me of the old Hasselblad V 100/3.5 lens that many fashion/portrait photograhers complained was too sharp for their needs and that was like 30+ years ago.

.

Yep...obviously great in lots of shooting situations but not what I personally would choose as a classic portrait lens (excepr if I was attempting to achieve a partiular look).

Dave (D&A)

 

[Kolor-Pikker]

Regarding the 90mm, there is no question that optically it is a superb lens, especially after having examined my test results, yet for me personally its a lens thats I often had trouble justifying. Its big, and relatively bulky for a single focal length 90mm medium format lens and is neither a true macro (goes down to 1:2 if I recall), and I wasn't enamored with it as a portrait lens. Too sharp for the latter. Although it would result in two lenses, I prefer having the 120mm macro and 150mm for portrait work. The latter is so light I often think they left out some of the elements .

There are a couple of factors at play here, the first one is that Pentax is still betting on the fact that one day a full 645 sensor will become available, and continues to make lenses that can cover that format, minus the revised 25mm which may produce vignetting.

The other factor is what I call the "Otus effect", where a lens can be anything from a $400 small plastic lens to a huge $4000 prime that's the size and weight of a 24-70mm zoom, but have the same basic parameters all to get that last 5% of performance. With the increasing demands of digital sensors, lenses are constantly getting bigger and heavier to give enough tolerance room for lens designers to create quality optics.

With each new lens Pentax comes out with, I see them getting better at targeting the needs of high-res imaging, with the 55 & 25mm being where they dropped the ball on not anticipating the needs of these sensors. Even though 51mp is technically not much more than 40mp, the same lenses I've used on the D do feel softer on the Z, so I expect them to continue to over-design their lenses... this will come at larger weight and size of course.

As for sharpness you can always turn it down during Raw conversion, you can soften something up, but you can't add back detail that's not there.

 

[algrove]

I just must have received a very good 55/2.8 as I have nothing, but praise for it at my end.

 

[Kolor-Pikker]

I just must have received a very good 55/2.8 as I have nothing, but praise for it at my end.

It is a good lens, but not "ERMAHGURD this is what I left 35mm for" good, at least at wide open aperture. Maybe I'm just being unreasonable, but the 645Z needs "killer" lenses like small format cameras have, including the Otus, Sigma 50mm Art, and the Sony 55/1.8 - something that can resolve the sensor edge-to-edge, lack any sort of CA wide open and act as the centerpiece of the system.

With the 55 SDM I find myself often stopping down to f/4+ to get good detail even when I don't need the extra depth of field, it's not as big a problem as on other systems due to the extreme usable ISO range, but I'd still rather take a sharp image at f2.8 and ISO1600 than f/4.5 and ISO4000.

Also apologies to Pradeep for hijacking his thread.

 

[D&A]

There are a couple of factors at play here, the first one is that Pentax is still betting on the fact that one day a full 645 sensor will become available, and continues to make lenses that can cover that format, minus the revised 25mm which may produce vignetting.

The other factor is what I call the "Otus effect", where a lens can be anything from a $400 small plastic lens to a huge $4000 prime that's the size and weight of a 24-70mm zoom, but have the same basic parameters all to get that last 5% of performance. With the increasing demands of digital sensors, lenses are constantly getting bigger and heavier to give enough tolerance room for lens designers to create quality optics.

With each new lens Pentax comes out with, I see them getting better at targeting the needs of high-res imaging, with the 55 & 25mm being where they dropped the ball on not anticipating the needs of these sensors. Even though 51mp is technically not much more than 40mp, the same lenses I've used on the D do feel softer on the Z, so I expect them to continue to over-design their lenses... this will come at larger weight and size of course.

As for sharpness you can always turn it down during Raw conversion, you can soften something up, but you can't add back detail that's not there.

Completely agree with your assessments that the 25 and 55mm lenses fell short in addressing the potential of both the 645D and 645z, especially that the 25mm was initially a $5,000 lens. The 55mm was an entry way lens much like the original FA 75mm was a entry way lens for the film 645 body. In that case some design compromises had to be made in order to reach a certain price point.

The reason images (especially those from the higher resolving new lenses) seem softer on the 645z is because of its use of a CMOS sensor vs. the 645D's CCD. If the same lens is used on both cameras to take the identical image and then sharpened appropriately for each camera, the differences in sharpness and ability to resolve detail is virtually the same.

Some samples of the 55mm are a bit sharper on edges and sides than others but if one examines their files carefully at higher magnification and are critical in their assessments, its generally noted that there is gradual falloff of side, edge and corner sharpness on most samples. Those areas are good but not great.

There are a number of reasons newely introduced lenses are designed for full frame 645. One is as you pointed out, the potential for a full frame 645 digital camera in the future. Secondly after Pentax scrapped its entire line of full frame 35mm lenses when they entered the digital fray with APS sensor DSLR's, they didn't take into account that one day they might re-enter that arena. They didn't want to make that mistake twice. Lastly there is still a good size contingent in Japan that still shoots with Pentax 645 film cameras.

Dave (D&A)