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Pentax 645Z vs A7RII IQ and bang for the buck

Pradeep

Member
Have you had a chance to use the 28-45mm lens? Its fantastic and gives hope that Pentax will do a similarly good job with the replacement 45-85 and 80-160 lenses, which may be coming fairly soon. The 28-45 is the best wide angle landscape lens I have ever used, because it offers top end prime quality with zoom convenience and SR. I used mine hand held a lot in Iceland, especially for quick roadside shots where a tripod would have been and issue (not to mention the wind and cold). FWIW its clearly better at 28mm than any of the 25mm D FA samples I've worked on in LR, towards the edges.

I haven't been that impressed by the edges of the 55mm D FA lens samples I have seen, whereas the 75mm FA seriously impressed me at landscape apertures. Its sharp as a tack everywhere, although it takes a few stops to get warmed up. Mine peaks at f9 across the field. Super happy with this inexpensive 200g wonder.

I'm itching for Pentax to get moving with new lenses and will most likely jump on the new 80-160mm.

It sound like Zeiss is working on an 18mm Batis, which will be interesting...
Tom, I've been working on the test images and I agree completely, a good lens is what makes the difference. I am seriously thinking about the 28-45 now that I am going to India for a Rajasthan tour next month. Still, the older lenses are quite extraordinary in their own way.

Pradeep
 

Pradeep

Member
Very curious to see your results Pradeep, I just took delivery of a 645z and I'm going to be trying similar tests to see what I'm gonna with the A7R2. I'm waiting now for the 75, 120 macro, and 150. I'm trying to decide what to do at the wide end.

turtle: I was very close to buying the 55 considering the great reviews people have online. However I don't understand why, I have not seen a single full-size image sample of this lens that has even decent corner performance, from what I've seen it's straight up bad for landscape. Maybe the reviews are from portrait shooters that are looking at the rendering and center performance.

How do you feel about the difference between the 35 A, and 28-45? Do you feel it's that much better regarding the cost difference? I don't mind shelling out for the 28-45 if it's a must have, but it's a huge chunk of change. My whole reason of switching to the 645z was to save money from the Phase system, the 28-45 would take a big bite out of that.
The 28-45 indeed is a lot of money, but expect that with most new lenses coming out for the 645 from here on. It is a big, hungry sensor and needs the best glass in front.

Anyway, here are some test shots. This was an absolutely unscientific comparison, I will admit right here and now. I was just curious to see if the Sony can come close. When I tested the Canon 5DSR against the Pentax, there was no comparison at all, the Pentax was simply better. Given that both are 50MP sensors the differences were obviously due to the size/technology of the sensors and the lenses I used.

I will repeat the methodology. I wanted to look at a simple backyard image, will probably do a test at infinity one of these days with buildings and such. Anyway, I put up the Edmund Optics Resolving chart up on my garage wall against a window. Testing different focal lengths is hard with this set up so all i did was equalize the FOV. Now I know that is not the best way to do it perhaps and the higher MP of the Pentax increases the size of the chart at 100%, but it is not too much of a difference, IMHO.

I tested the Batis 25 and 85 on the Sony along with the ZA 35 2.8, 55 1.8 and also used two Canon lenses with the Metabones adapter (Mk IV with the latest firmware).

For the Pentax I used the FA 45-85 f4.5, the DFA 55 2.8, the FA 120 f4 macro and the FA 150 2.8 I seem to have misplaced my FA 75 but will test that another day. I took multiple shots at 1-stop interval starting from wide open to f11. Tripod, mirror up, self-timer etc.

These are all JPG versions. I can upload the RAW files if I can figure out how. In my testing previously, I had discovered that my sharpest non-wide lens on the Sony is the 85 Batis and on the Pentax my overall sharpest is the 150 2.8 (my copy of the famed 120 macro is less than stellar). So here are images from the Batis 85 and the FA 150 both at f8 since we are talking landscape apertures.

I will leave the comments for you all. Attaching a few more images in the next post..........

001_Test_20151109_7R2_4529©PradeepBansal2015-Edit.jpg002_Test_20151109_7R2_4529©PradeepBansal2015-Edit-2.jpg003_Test_20151109_7R2_4529©PradeepBansal2015-Edit-3.jpg004_Test_20151109_P6Z_6388©PradeepBansal2015-Edit.jpg005_Test_20151109_P6Z_6388©PradeepBansal2015-Edit-3.jpg006_Test_20151109_P6Z_6388©PradeepBansal2015-Edit-4.jpg
 
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Pradeep

Member
I followed up the above images with another test.

I feel that in order to compare two cameras one needs to look at several things - apart from the size, heft, cost, ergonomics, weather sealing etc - which are all non-IQ factors. Simply comparing the image quality coming out of one camera with another requires equalization of lenses which is very difficult to do between MF and 35mm. Interestingly, it is easy now to compare the Sony with the Canon/Nikon since you can put on the same lenses on both cameras.

Other factors like DR, noise levels, are all important in the final equation. So I thought I would do a noise and DR test too.

These shots were taken with the two cameras underexposed by at least 4 stops, I then pulled up the exposure in LR to the maximum I could, which was five stops.

Both cameras have an amazing ability to pull up shadow detail. I will let you decide which one does a better job.

007_Test_20151109_7R2_4534©PradeepBansal2015-Edit.jpg008_Test_20151109_7R2_4534©PradeepBansal2015-Edit-2.jpg009_Test_20151109_7R2_4534©PradeepBansal2015-Edit-3.jpg010_Test_20151109_P6Z_6421©PradeepBansal2015-Edit.jpg011_Test_20151109_P6Z_6421©PradeepBansal2015-Edit-2.jpg012_Test_20151109_P6Z_6421©PradeepBansal2015-Edit-3.jpg
 

tsjanik

Well-known member
Very curious to see your results Pradeep, I just took delivery of a 645z and I'm going to be trying similar tests to see what I'm gonna with the A7R2. I'm waiting now for the 75, 120 macro, and 150. I'm trying to decide what to do at the wide end.

turtle: I was very close to buying the 55 considering the great reviews people have online. However I don't understand why, I have not seen a single full-size image sample of this lens that has even decent corner performance, from what I've seen it's straight up bad for landscape. Maybe the reviews are from portrait shooters that are looking at the rendering and center performance.

How do you feel about the difference between the 35 A, and 28-45? Do you feel it's that much better regarding the cost difference? I don't mind shelling out for the 28-45 if it's a must have, but it's a huge chunk of change. My whole reason of switching to the 645z was to save money from the Phase system, the 28-45 would take a big bite out of that.
I'm not Pradeep or turtle, but I have the 35mm A and the 28-45mm. I did a brief comparison of the A vs. zoom at 35mm. The zoom is a little better in the corners and a bit less CA and the A has some very slight barrel distortion, but you really need to pixel peek to see the difference. The 35mm is a lens you can walk around with and is about 1/10 the cost, size and weight of the zoom (a slight exaggeration, but not that far off). I'm keeping both lenses, the A if I need to carry something and don't need the extra width of the zoom; the zoom because it's really excellent at all its focal lengths. I had a FA 35mm as well and sold it, I found the A version to be a better copy.

Tom
 

Paul2660

Well-known member
Pradeep:

Thanks for the images.

To my eyes, the Sony is showing a good bit of deal loss in the darker areas and increase in noise, looking at the darker bricks, the sprinkler shaft, and the control box. The Pentax looks a lot cleaner in these darker spots.

I assume you shot at base iso for both?

I noticed a problem with shadow noise recovery with the A7rII I briefly owned, which surprised me considering the tech behind the sensor in the Sony. Was it extreme? No, but it was worse than my D810 at iso 64. I shot the Sony at 100 and 200 iso.

Paul C
 

Ed Hurst

Well-known member
Tom - my experience of the 35mm A and the 28-45 zoom led to the same conclusions. The zoom is better when examined closely but the 35mm A is close and handy for situations where the bulk of the zoom is not desirable. Also the f3.5 maximum aperture of the prime is occasionally useful, even in this world of clean high ISO and IS.
 

tsjanik

Well-known member
Tom - my experience of the 35mm A and the 28-45 zoom led to the same conclusions. The zoom is better when examined closely but the 35mm A is close and handy for situations where the bulk of the zoom is not desirable. Also the f3.5 maximum aperture of the prime is occasionally useful, even in this world of clean high ISO and IS.
Ed, interesting that you have found the same; sometimes I think my experience applies only to the copies I have since some reports are quite contrary to my observations. The old 35, 75 and 120mm are hard to surpass and many of the older lenses are quite good. You and I both use the 67 300mm M*; it may surprise you that based on my limited tests, the 150-300mm zoom is almost its equal (F/8, where I shoot).

Tom
 

Ken_R

New member
Tom - my experience of the 35mm A and the 28-45 zoom led to the same conclusions. The zoom is better when examined closely but the 35mm A is close and handy for situations where the bulk of the zoom is not desirable. Also the f3.5 maximum aperture of the prime is occasionally useful, even in this world of clean high ISO and IS.
I still have the 35A and it is a miracle lens I mean, it is quite small and light and still covers the full frame 645 format. Baffled how even today no one can make a high quality wide angle lens for medium format that is Not HUGE.

The 28-45mm is massive but it is much wider and has IS so ill allow it. :cool:
 

hcubell

Well-known member
Tom, I've been working on the test images and I agree completely, a good lens is what makes the difference. I am seriously thinking about the 28-45 now that I am going to India for a Rajasthan tour next month. Still, the older lenses are quite extraordinary in their own way.

Pradeep
Your choice and off topic, but I think you would be much better off taking/renting a Sony A7SII and a Sony A7RII with the two Batis lenses and the FE 24-70 zoom to Rajastan. I spent three weeks walking around the back streets and alleys of Rajastan from early morning till well into the evening with the original A7S and the FE 24-70 zoom. The new A7SII is even better with the IBIS. You will be often be shooting in low light where this camera body will excel at amazingly high ISOs. The FE 24-70 is certainly not my first choice for landscapes, but I personally don't think that photographing in Rajastan is about sharp corners on brick walls. The lens is quite sharp in the center. I also had the FE 35, 55 and 70-200, but the 24-70 rarely came off the camera. I also had an A7R for good light.
 

Pradeep

Member
Pradeep:

Thanks for the images.

To my eyes, the Sony is showing a good bit of deal loss in the darker areas and increase in noise, looking at the darker bricks, the sprinkler shaft, and the control box. The Pentax looks a lot cleaner in these darker spots.

I assume you shot at base iso for both?

I noticed a problem with shadow noise recovery with the A7rII I briefly owned, which surprised me considering the tech behind the sensor in the Sony. Was it extreme? No, but it was worse than my D810 at iso 64. I shot the Sony at 100 and 200 iso.

Paul C
Paul, all shots were taken at ISO 100 which I think is the base for both cameras. I believe both sensors exhibit the 'ISO invariance' phenomenon too, I don't know how many here believe that in real life.

Anyway, you are correct, the Sony does show loss of detail and higher levels of noise, perhaps something to be expected given the smaller sensor.
 

Pradeep

Member
Your choice and off topic, but I think you would be much better off taking/renting a Sony A7SII and a Sony A7RII with the two Batis lenses and the FE 24-70 zoom to Rajastan. I spent three weeks walking around the back streets and alleys of Rajastan from early morning till well into the evening with the original A7S and the FE 24-70 zoom. The new A7SII is even better with the IBIS. You will be often be shooting in low light where this camera body will excel at amazingly high ISOs. The FE 24-70 is certainly not my first choice for landscapes, but I personally don't think that photographing in Rajastan is about sharp corners on brick walls. The lens is quite sharp in the center. I also had the FE 35, 55 and 70-200, but the 24-70 rarely came off the camera. I also had an A7R for good light.
Thanks Howard. That is very helpful. I've been sitting on the fence on this issue, whether to take both the Pentax and the Sony or just the smaller camera with me. We will be traveling a lot and there will be times when a lighter outfit would be better. For example, we are also doing the Taj (including moonlight visit) and I don't want to frighten the security staff with huge cameras and lenses ;)

I actually do have a 24-70 but I think my copy is a bit soft, never liked it much. Given the need for wide and mid-range FL, a zoom would be perfect, but I may just take two A7 series bodies and put different lenses on both to give me the coverage.

Do you think the A7SII is significantly better at low-light stuff? At the Taj for example, moonlight shots would require an ISO of at least 3200 given no tripods are allowed. I might just rent one in that case.
 
The 28-45 indeed is a lot of money, but expect that with most new lenses coming out for the 645 from here on. It is a big, hungry sensor and needs the best glass in front.

Anyway, here are some test shots. This was an absolutely unscientific comparison, I will admit right here and now. I was just curious to see if the Sony can come close. When I tested the Canon 5DSR against the Pentax, there was no comparison at all, the Pentax was simply better. Given that both are 50MP sensors the differences were obviously due to the size/technology of the sensors and the lenses I used.

I will repeat the methodology. I wanted to look at a simple backyard image, will probably do a test at infinity one of these days with buildings and such. Anyway, I put up the Edmund Optics Resolving chart up on my garage wall against a window. Testing different focal lengths is hard with this set up so all i did was equalize the FOV. Now I know that is not the best way to do it perhaps and the higher MP of the Pentax increases the size of the chart at 100%, but it is not too much of a difference, IMHO.

I tested the Batis 25 and 85 on the Sony along with the ZA 35 2.8, 55 1.8 and also used two Canon lenses with the Metabones adapter (Mk IV with the latest firmware).

For the Pentax I used the FA 45-85 f4.5, the DFA 55 2.8, the FA 120 f4 macro and the FA 150 2.8 I seem to have misplaced my FA 75 but will test that another day. I took multiple shots at 1-stop interval starting from wide open to f11. Tripod, mirror up, self-timer etc.

These are all JPG versions. I can upload the RAW files if I can figure out how. In my testing previously, I had discovered that my sharpest non-wide lens on the Sony is the 85 Batis and on the Pentax my overall sharpest is the 150 2.8 (my copy of the famed 120 macro is less than stellar). So here are images from the Batis 85 and the FA 150 both at f8 since we are talking landscape apertures.

I will leave the comments for you all. Attaching a few more images in the next post..........
What I find particularly noticeable is how much better surface texture is preserved by the larger sensor, especially in the brickwork where the Sony just says "here's some bricks" while in the Pentax shot you can see the roughness of everything.
 

torger

Active member
Concerning color response I've profiled both cameras (using imaging resource images, haven't actually held the cameras in person) and the respond so similar that I think they have the exact same color filters on the sensors.

If you're a Capture One fan you can use A7rII there but not the Pentax 645z (unless hacking C1) which may be a factor.

If anyone's interested in my A7r-II and 645z DNG profiles you can download them here:

http://torger.dyndns.org/dcamprof-v0104-pentax-645z-neutral.dcp
http://torger.dyndns.org/dcamprof-v0104-pentax-645z-neutral-plus.dcp
http://torger.dyndns.org/dcamprof-v0104-sony-a7r2-neutral.dcp
http://torger.dyndns.org/dcamprof-v0104-sony-a7r2-neutral-plus.dcp

The "neutral+" variants contains some (very) mild subjective adjustments. It's possible to make C1 profiles too, but I haven't done that for the A7r-II.
 

hcubell

Well-known member
Concerning color response I've profiled both cameras (using imaging resource images, haven't actually held the cameras in person) and the respond so similar that I think they have the exact same color filters on the sensors.

If you're a Capture One fan you can use A7rII there but not the Pentax 645z (unless hacking C1) which may be a factor.

It's possible to make C1 profiles too, but I haven't done that for the A7r-II.
If you ever have the spare time, it would be really interesting to compare them with C1's own A7RII profiles.
 

hcubell

Well-known member
Thanks Howard. That is very helpful. I've been sitting on the fence on this issue, whether to take both the Pentax and the Sony or just the smaller camera with me. We will be traveling a lot and there will be times when a lighter outfit would be better. For example, we are also doing the Taj (including moonlight visit) and I don't want to frighten the security staff with huge cameras and lenses ;)

I actually do have a 24-70 but I think my copy is a bit soft, never liked it much. Given the need for wide and mid-range FL, a zoom would be perfect, but I may just take two A7 series bodies and put different lenses on both to give me the coverage.

Do you think the A7SII is significantly better at low-light stuff? At the Taj for example, moonlight shots would require an ISO of at least 3200 given no tripods are allowed. I might just rent one in that case.
Have a look here at the opinion of one person who has tested them side by side. http://www.mirrorlessons.com/2015/11/06/sony-a7r-ii-vs-a7s-ii.
Given the IBIS on the new A7RII, I might skip the A7SII and just go with the A7RII that you already have. However, you should have a second body as a backup, so you could rent either the A7SII or another A7RII. You might also consider renting a "good" copy of the FE 24-70 from lensrentals.com before the trip and see what you think. My website has a portfolio from a trip to India last year that were shot primarily with the A7S and the FE 24-70 zoom.
 

Paul2660

Well-known member
I am waiting for my XF but do have the Schneider 40-80mm lens on my DF. I think it's a better choice over the new 35mm and it's extremely sharp. I got it for the same price as the new 35mm. Sure it would be great to have both but the cost is prohibitive for me anyway.

Check out this full rez stitch from Telluride. Shot with IQ180 at 40mm on the 40-80mm.

https://www.dropbox.com/s/9f2mi5krrgbkbgl/pano-37.tif?dl=0
HI Doug:

Thanks for the link. I agree the 40-80 is an exceptional optic. I just can't justify the price point, @ 8.4K, as I recall. I also find that I still need a bit wider range. The 40mm HR-W is by far one of the best lenses I have used, but most times I needed to shift it to get the full image I need.

I am waiting on a 35LS, hoping to see the same degree of sharpness, to the corners, I have seen in the test samples.

My plan is the 35, 55LS and 80LS, and eventually pickup a 150mm 2.8 as it's one of the best optics Mamiya ever made.

Paul C
 

kdphotography

Well-known member
Hi Paul,

110LS and/or 120mm would be a nice fit to fill the gap between the 80LS and 150mm.

Might as well get the 240LS too since you're shopping.

:ROTFL:
 

Pradeep

Member
Have a look here at the opinion of one person who has tested them side by side. http://www.mirrorlessons.com/2015/11/06/sony-a7r-ii-vs-a7s-ii.
Given the IBIS on the new A7RII, I might skip the A7SII and just go with the A7RII that you already have. However, you should have a second body as a backup, so you could rent either the A7SII or another A7RII. You might also consider renting a "good" copy of the FE 24-70 from lensrentals.com before the trip and see what you think. My website has a portfolio from a trip to India last year that were shot primarily with the A7S and the FE 24-70 zoom.
Thanks Howard, that's made the decision for me. I will probably get another A7RII body now. Wonder why the A7SII is the same price with a lower MP resolution. Just the enhanced video capabilities should not push the price up that much. I guess they don't want it to eat up into the RII sales.

Looked at your Rajasthan gallery. Very good stuff. I am not into portraits, especially those of indigenous peoples, I have a problem with that. But that's just my problem I guess. In any case, I grew up with such sights around me so it is nothing 'exotic' as far as I am concerned. The vistas and little streets of the villages still fascinate me, so that would be my focus, of course apart from the iconic monuments and historical artifacts.
 

torger

Active member
If you ever have the spare time, it would be really interesting to compare them with C1's own A7RII profiles.
I don't use C1 much these days so I haven't cared to upgrade the software, and my version (7.2.2) doesn't support A7R-II images so I can't make any profiles for it unfortunately :-/
 

DougDolde

Well-known member
HI Doug:

Thanks for the link. I agree the 40-80 is an exceptional optic. I just can't justify the price point, @ 8.4K, as I recall. I also find that I still need a bit wider range. The 40mm HR-W is by far one of the best lenses I have used, but most times I needed to shift it to get the full image I need.

Paul C
Paul, Digital Transitions has a "used" one for $6,455. Thats where I got mine. They are "as new" and according to Lance were sold to a NYC studio that subsequently decided not to use them.

It's a beast for sure but I'm getting used to it. Big benefit is not needing to change lenses so often.
 
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