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12-10-2018, 12:22 AM - 4 Likes   #1
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Grand Lens Test 13A: APPROVED. The real DA645 28-45 ED AW SR is in the house

Series Contents

Those of you who read the prior test of the DA645 28-45 will know the story. I purchased a pre-owned lens from Adorama at a good price, and the lens turned out to be a problem performer. It was fine at some angles, but when level on the tripod, aimed at my test scene, it did not match the performance of either the 35mm prime or the 45mm end of the 45-85 zoom, and it missed by a mile. My suspicion is that something that is supposed to not be loose was, and fell out of alignment under certain conditions and into alignment at other times. Adorama took it back without a hiccup, and I sent that money to Australia to a forum member who offered me his lens instead. The beast was proving physically unmanageable for him, and I can understand that. It is indeed a beast, as all who have reviewed it will confirm. But compared to my Sinar P, it's light as a feather. And compared to a Zeiss Jena 180mm f/2.8 Sonnar (or, Heaven forbit, the 300), it's not particularly beastly. Put that Sonnar on a Kiev 60, and carry that around for a bit. Or a Pentax 67 with a 300mm lens and TTL finder. You'll never complain about the 645z again.

But I do consider carrying it around as part of my workout regimen. I warm up using my dumbbells, usually in the range of 35-50 pounds each, as a warm up for the big lift of carrying this puppy. Okay, it's not that bad, but it will still be favored by those who work out in the gym.

Today I made new test photos with the replacement lens, and conditions were a bit more like my original test in terms of lighting. It was a gray day just as it was in the late spring when I tested the other lenses in this series. But unlike that prior occasion, it never made it above freezing here so the camera got a bit of a cold-weather workout. The winter conditions also mean that the bushes and trees at Chez Denney are more leafless than in prior photos.

Here's a general view at 28mm:



As before, these are straight out of the camera, processed in DxO Photolab with the driest possible settings.

28mm

Here's a 100% crop from the middle of the image, at f/4.5. Remember that these 1:1 crops, when displayed on a typical monitor at 100 pixel/inch, are part of an image seven feet wide.



One of the tests of a zoom is whether it's better to carry a range of primes. The only good prime that competes at this end of the zoom range is the DA or DFA 25mm lens, which is of course no longer in production. The only lens I have in my collection that hopes to compete at this focal length is an Arsat 30mm Fisheye. So, what the heck, let's show the center crop from that lens (which is itself also a beast). Here is the image made at f/11, so we are comparing the best aperture of that lens with the wide-open aperture of the 28-45.



The Arsat doesn't stand a chance. But if you need a fisheye, and only a fisheye will do, then the Arsat is one.

But the real test of a wide-angle lens is in the corners. Is there field curvature? Does the sharpness hold up in the corners? Let's look. Here's the lower right corner:



This isn't curvature--it's just loss of sharpness in the extreme corner at f/4.5. But this IS just the very corner--compare this with the full image above. We're talk the four or five inches from the corner on that seven-foot print. This loss of sharpness in the corner nearly completely cleans up at f/5.6, and we'll look at f/8 further down and see that the effect is completely resolved once we've stopped down a bit.

What about curvature: Here's the upper left corner:



The branches you see are about in the focus plane, and they are sharp. The loss of sharpness that would correspond to the lower right corner is suffused into the bit of house that is quite out of focus. I don't see evidence of curvature here.

And here's the lower left corner, which was generally sharp with the FA35 (which is known for curvature). The field looks acceptably flat at 28mm.

While we are at 28mm, let's look at several apertures and see if we can determine the ideal aperture. Here's the center again at f/5.6:



f/8:


f/11:


f/16:


And f/22:


There is no practical difference between f/4.5, 5.6, 8, and 11 in the center of the image and in the focus plane. F/16 starts to degrade slightly, though I may be imagining it, but not enough to keep me from using it even for a large print. F/22, though, would allow only a more subdued print size. But insufficient depth of field trumps diffraction.

Before moving away from 28mm, here's the lower right corner at f/8:


At f/8, it's sharp right to the corner.

35mm

I'll spend less time at longer focal lengths now that we know the basic behavior of the lens. Questions for 35mm: Does it out-perform the FA35mm prime lens? Are the corners better than at 28?

Here's the center at f/4.5:


F/5.6:


And at f/8:


Here is the FA 35/3.5 at f/11:


This makes me want to check that f/8 exposure, which is very slightly softer than the f/4.5 image. F/5.6 is the clear winner of all of these, but the 35 may be diffracting a touch at f/11. The 35mm prime is very good in the center, but it's not better than the zoom. It is a LOT cheaper, though.

Here is the upper left corner at f/8:


Again, no sign of field curvature. The branches and dead leaves are close to the focal plane. The wood at left is only five feet from the lens, and the background pines are three times as far as the focus plane. There is a touch of movement blur here--shutter speed was 1/13 second. The camera was, of course, mounted on a tripod, but that river birch tree will move in not much breeze.

45mm

Center of the image at 1:1, F/4.5:


Here's the 45-85 zoom at 45 and f/4.5:


The 45-85 is stunningly good, especially at the short end. The 28-45 is a bit better.

Here's the same comparison at f/8:




Again, the 45-85 is outstanding, and the 28-45 is a bit better.

Finally, a word about focus accuracy. This lens front-focused very slightly, and I set the focus adjustmentment for this one to -3.

In conclusion, a good example of the 28-45 is an amazing performer. Please see my previous test of the failed lens for details about shake reduction, which I did not test again here. I find that shake reduction is good for about a stop, but I did not use it in the above images that were made on a tripod using mirror pre-release.

But these lenses are not bullet-proof. If you buy one pre-owned, test it.

Rick "just about thawed out" Denney


Last edited by rdenney; 12-10-2018 at 12:33 AM.
12-10-2018, 12:20 PM   #2
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Thanks for this extensive test. I think I read somewhere that the sample variations were ultimately what caused Pentax or it's successors to discontinue this lens, something I find to be a problem and has kept me from expanding my 645 shooting rig. Ultimately, with Fuji and Hasselblad now issuing lenses in the ultra-wide category that Pentax first served, it is hard to justify big bucks for acquiring new digital bodies and lenses when you are a wide-angle, landscape shooter like me - sadly.
12-10-2018, 03:01 PM   #3
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QuoteOriginally posted by mtgmansf Quote
Thanks for this extensive test. I think I read somewhere that the sample variations were ultimately what caused Pentax or it's successors to discontinue this lens, something I find to be a problem and has kept me from expanding my 645 shooting rig. Ultimately, with Fuji and Hasselblad now issuing lenses in the ultra-wide category that Pentax first served, it is hard to justify big bucks for acquiring new digital bodies and lenses when you are a wide-angle, landscape shooter like me - sadly.


The 28-45 is not discontinued that I know of. Itís the 25 that is no longer being made, reportedly because they lost their contractor who could make the front element within their cost structure.

Rick ď28 is about as wide as I go before getting into seriously limited applicabilityĒ Denney
12-10-2018, 06:32 PM   #4
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QuoteOriginally posted by rdenney Quote
The 28-45 is not discontinued that I know of. Itís the 25 that is no longer being made, reportedly because they lost their contractor who could make the front element within their cost structure.

Rick ď28 is about as wide as I go before getting into seriously limited applicabilityĒ Denney
I stand corrected. I must have been thinking about the 25mm. Unfortunately, 28mm is only about 24mm on the 645z, which is not wide enough for many of us...

12-10-2018, 07:41 PM   #5
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QuoteOriginally posted by mtgmansf Quote
I stand corrected. I must have been thinking about the 25mm. Unfortunately, 28mm is only about 24mm on the 645z, which is not wide enough for many of us...

Itís wider than you think. Based on the diagonal, itís more like 22 equivalent: 43/55 times 28. If the target aspect ratio is 4x3, itís more like 20: 24/33 times 28. Itís only 23 if you want a 3x2 aspect: 36/44 times 28.

I print to 16x20 or at 4x3, so for me itís pretty wide, and wider than anything Iíve used in medium format except 6x12. 28 is the same for the 645z as the 45 is for 6x7.

A wider lens really is occasionally useful, but I find Iím using ultrawides less often than I once predicted. I had an 18-28 zoom on my Canon F-1 back in the day, and I look at those 18mm images now and wonder what I was thinking. It worked a treat maybe one out of a hundred times, but most of the time, perspective was too hard to control. It was nice in those rare occasions, but there are lots of other photos to make.

Rick ďnot arguing that an ultra wide prime wouldnít be impressive in the product lineĒ Denney
12-11-2018, 01:40 AM   #6
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QuoteOriginally posted by rdenney Quote
Itís wider than you think. Based on the diagonal, itís more like 22 equivalent: 43/55 times 28. If the target aspect ratio is 4x3, itís more like 20: 24/33 times 28. Itís only 23 if you want a 3x2 aspect: 36/44 times 28.

I print to 16x20 or at 4x3, so for me itís pretty wide, and wider than anything Iíve used in medium format except 6x12. 28 is the same for the 645z as the 45 is for 6x7.

A wider lens really is occasionally useful, but I find Iím using ultrawides less often than I once predicted. I had an 18-28 zoom on my Canon F-1 back in the day, and I look at those 18mm images now and wonder what I was thinking. It worked a treat maybe one out of a hundred times, but most of the time, perspective was too hard to control. It was nice in those rare occasions, but there are lots of other photos to make.

Rick ďnot arguing that an ultra wide prime wouldnít be impressive in the product lineĒ Denney
Interesting set of test results - thks - I've looked at the 35mm and 45mm, but went for the zoom plus the widest they offer ….I have both the 28-45mm and 25mm...both deliver excellent results in my experience....the 25mm gives useful additional latitude despite the relatively small reduction in f-length over the 28-45mm....the 25mm is used often for interiors, and a vertical floor to ceiling pano of our cathedral interior was possible on only 2 stitched frames.......I assume the Arsat fisheye to go for is the later MC version?
Hassy have a 21mm for the X1D mirrorless (approx. equiv. 16mm on FF 35mm?), but nothing wider yet from Pentax for the 645 tribe among us....for my 'walking around' shooting needing extra-wide coverage I use the Fuji X-T20 with the 10-24mm, which also gives surprisingly decent results, despite being 'only' 24MP and APSC....
12-11-2018, 06:48 AM   #7
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Grand Lens Test 13A: APPROVED. The real DA645 28-45 ED AW SR is in the house

QuoteOriginally posted by BostonUKshooter Quote
Interesting set of test results - thks - I've looked at the 35mm and 45mm, but went for the zoom plus the widest they offer Ö.I have both the 28-45mm and 25mm...both deliver excellent results in my experience....the 25mm gives useful additional latitude despite the relatively small reduction in f-length over the 28-45mm....the 25mm is used often for interiors, and a vertical floor to ceiling pano of our cathedral interior was possible on only 2 stitched frames.......I assume the Arsat fisheye to go for is the later MC version?
Hassy have a 21mm for the X1D mirrorless (approx. equiv. 16mm on FF 35mm?), but nothing wider yet from Pentax for the 645 tribe among us....for my 'walking around' shooting needing extra-wide coverage I use the Fuji X-T20 with the 10-24mm, which also gives surprisingly decent results, despite being 'only' 24MP and APSC....
I do have some ultrawides--a Sigma 12-24, for example, for my full-frame Canons--but it's been a long time since I've had it on the camera. The 24-105 sits on the camera routinely, even for landscape work. I guess it expresses my own shift in thinking that when the Canon 17-40 f/4 L came out, I lusted for it, but still have managed to not buy it despite that used examples are rather affordable now.

And I have and very occasionally use a 65mm Super Angulon for 4x5. The 65 is good for interiors and exaggerated closeups, and perspective control is a bit more possible with 4x5 though that lens's image circle isn't that big, but using it causes the same problem I have with any extreme wide for general landscapes--it renders distant land too small in the image to see. The 47mm Super Angulon XL is available and I've had several opportunities to buy one at a good price, but have never followed through, simply because I doubt I'd get any use out of it. A 65 on 4x5 is like a 24 or 25 on the 645z, and if the right deal came along on a 25 at a time when I was feeling flush, I might jump on it.

I've said in the past that Pentax needs to be able to say they have an extreme wide in the line. It does not have to be fast, even. f/5.6 would be acceptable.

My Arsat is multicoated, but you'll notice veiling flare on that lens when pointed into the light. But I can usually fix that, as in the image below.



Rick "the 30mm Arsat isn't really any wider than the 28 end of this zoom, especially if you want to correct the fisheye distortion" Denney
12-11-2018, 08:57 AM   #8
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QuoteOriginally posted by rdenney Quote
I do have some ultrawides--a Sigma 12-24, for example, for my full-frame Canons--but it's been a long time since I've had it on the camera. The 24-105 sits on the camera routinely, even for landscape work. I guess it expresses my own shift in thinking that when the Canon 17-40 f/4 L came out, I lusted for it, but still have managed to not buy it despite that used examples are rather affordable now.

And I have and very occasionally use a 65mm Super Angulon for 4x5. The 65 is good for interiors and exaggerated closeups, and perspective control is a bit more possible with 4x5 though that lens's image circle isn't that big, but using it causes the same problem I have with any extreme wide for general landscapes--it renders distant land too small in the image to see. The 47mm Super Angulon XL is available and I've had several opportunities to buy one at a good price, but have never followed through, simply because I doubt I'd get any use out of it. A 65 on 4x5 is like a 24 or 25 on the 645z, and if the right deal came along on a 25 at a time when I was feeling flush, I might jump on it.

I've said in the past that Pentax needs to be able to say they have an extreme wide in the line. It does not have to be fast, even. f/5.6 would be acceptable.

My Arsat is multicoated, but you'll notice veiling flare on that lens when pointed into the light. But I can usually fix that, as in the image below.



Rick "the 30mm Arsat isn't really any wider than the 28 end of this zoom, especially if you want to correct the fisheye distortion" Denney
All noted - thks Rick!

12-11-2018, 02:29 PM   #9
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QuoteOriginally posted by mtgmansf Quote
I stand corrected. I must have been thinking about the 25mm. Unfortunately, 28mm is only about 24mm on the 645z, which is not wide enough for many of us...
I had a love-hate relationship with the 28-45mm and in the end I decided it was too heavy and not wide enough. I now have a Phase One P65+ and use a converted Samyang 24mm Shift lens (now non-shifting). On the full-frame P65+ the 24mm Samyang gives the equivalent of a 15mm lens! Nice and small and light, too.

The small 35mm is also equivalent to a 22mm. Perfect travel lens.
12-13-2018, 02:37 AM   #10
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QuoteOriginally posted by Sarnian Quote
I had a love-hate relationship with the 28-45mm and in the end I decided it was too heavy and not wide enough. I now have a Phase One P65+ and use a converted Samyang 24mm Shift lens (now non-shifting). On the full-frame P65+ the 24mm Samyang gives the equivalent of a 15mm lens! Nice and small and light, too.

The small 35mm is also equivalent to a 22mm. Perfect travel lens.
Image quality @ 65MP from that 24mm lens?
12-13-2018, 12:21 PM - 1 Like   #11
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Surprisingly good! Here's a dropbox link to a jpeg (the TIFF is twice as good): Dropbox - Samyang 24 non-TS equivalent to c15mm CF006109.jpg

By the way, the effective pixel count of the P65+ is 60.5MP's.
12-13-2018, 01:37 PM   #12
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QuoteOriginally posted by Sarnian Quote
I had a love-hate relationship with the 28-45mm and in the end I decided it was too heavy and not wide enough. I now have a Phase One P65+ and use a converted Samyang 24mm Shift lens (now non-shifting). On the full-frame P65+ the 24mm Samyang gives the equivalent of a 15mm lens! Nice and small and light, too.

The small 35mm is also equivalent to a 22mm. Perfect travel lens.
Who/how was the conversion done, since the flange distance is very much shorter for the Samyang- either in Canon or Nikon mount- shift to Mamiya lens mount?

Many thanks,

Peter
12-13-2018, 03:44 PM   #13
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QuoteOriginally posted by mtgmansf Quote
Who/how was the conversion done, since the flange distance is very much shorter for the Samyang- either in Canon or Nikon mount- shift to Mamiya lens mount?

Many thanks,

Peter
Hi Peter,

Take a look here: Now! Ultra wide angle Samyang 24mm/3,5 adapted for Mamiya 645 Phase One 28 35 45 | eBay He's sold at least 3 others since mine.

I guess the removal of the T/S mechanism gives him the room to play with that he needs. The converted lens is quite hard to focus as there's not much room to play with. The P65+ doesn't have Live View so that makes it harder. The lens is definitely a keeper and will be even easier to use when I eventually get my hands on an IQ-range Phase One back with Live View.

I'll put a sharper example on Dropbox either tomorrow or over the weekend.

The lens is so small and light it's a no brainer.

Mark
12-13-2018, 05:26 PM   #14
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QuoteOriginally posted by Sarnian Quote
Hi Peter,

Take a look here: Now! Ultra wide angle Samyang 24mm/3,5 adapted for Mamiya 645 Phase One 28 35 45 | eBay He's sold at least 3 others since mine.

I guess the removal of the T/S mechanism gives him the room to play with that he needs. The converted lens is quite hard to focus as there's not much room to play with. The P65+ doesn't have Live View so that makes it harder. The lens is definitely a keeper and will be even easier to use when I eventually get my hands on an IQ-range Phase One back with Live View.

I'll put a sharper example on Dropbox either tomorrow or over the weekend.

The lens is so small and light it's a no brainer.

Mark
Dear Mark,

Thank you very much for this detailed response. Unfortunately, the seller does not ship to the U.S.A., but I will write him to see if I can change his mind or find someone in the States to do the mod.

Peter

Last edited by mtgmansf; 12-13-2018 at 05:47 PM.
12-14-2018, 12:51 AM   #15
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QuoteOriginally posted by mtgmansf Quote
Dear Mark,

Thank you very much for this detailed response. Unfortunately, the seller does not ship to the U.S.A., but I will write him to see if I can change his mind or find someone in the States to do the mod.

Peter
Hi Peter,

I'm sure that he would post to the U.S.A. Send him a message. In fact, someone over at the getdpi forum bought one after seeing my posts about it and I'm pretty sure that he lives in the U.S.

Here's another jpeg: Dropbox - Samyang 24mm f16 ISO 50 CF006289.jpg Both images were handheld.

Mark
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