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01-07-2011, 12:46 AM   #1
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645D Performance with Existing Wide Angle Lenses

I've been shooting with a 645NII and the 33-55mm lens for years. I can easily print great looking 24x33" prints and even 43x56" prints on my Epson 9800.

I've seriously considering the possiblity of the new 645D. But I wonder how my 33-55mm and 55-110mm lenses will perform given what Pentax Product Planning executive Yasuyuki Maekawa said in his interview with Luminous Landscape. He stated that he's not totally happy with the image quality on the wide end.

Yes, they are offering a new 25mm f/4 lens (equivalent of 20mm in 35mm format), but that still leaves a big gap in focal length that I was hoping the 33-55mm lens could fill for my landscape work. I was really hoping they would have developed a zoom at the wide range. Too bad.

So, does anyone have any practical insights into how the 33-55mm and 55-110 performs with the 645D in terms of landscape work, which means small apertures and hyperfocal distance? On the 645NII, I frequently shoot between f/22 and f/32 because my nearest subject distance is frequently in the range of 18 to 24 inches (or 46 to 61cm for you metric folks). That's because I take lots of prairie landscapes where I push the lens very close to the foreground flowers. The apertures of f/32 and f/22 on the 645NII are the same as f/25 and f/18 on the 645D, respectively (calculated based on crop factor).

And, finally, I'm wondering if there's any news about what the smallest aperture is on the upcoming 25mm lens.

Thanks!
Mike

01-07-2011, 08:28 AM   #2
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I recently did a series of 'sharpness' tests of 5 645 lenses on a 645D, in studio, at a 50:1 image ratio (see the thread "645D lens test results"). I did not test the lenses you mention, nor did I test anything wider than 55mm. However, with every lens/focal length combo I did test, there was significant degradation from diffraction by the time you got within 1 stop of minimum aperture. It was very consistent. That would be f/16-22 on the f/2.8 lenses, and f/22-32 on the f/4 and f/4.5 lenses.

(I'm calling these 'sharpness' tests and not 'resolution' tests, because even though I used resolution targets, I didn't quantify anything. Judgements were made on minimally processed images viewed on a computer screen at 100%.)

That's not to say good pictures can't be made at these small apertures, but it seems to me that sharpening protocol and print size considerations would be critical.


Tim Wilson
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01-07-2011, 09:17 AM   #3
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See my posts days ago (page 3 on 33-55 and page 2 on the 35mm):

https://www.pentaxforums.com/forums/pentax-medium-format-645-6x7-645d/126674-...ns-645d-3.html

and an "aperture series" full resolution JPEGs from a 33-55 at 33mm from Japan:

?????6?????????????PENTAX645D????????????????????
http://translate.google.com/translate?hl=en&sl=ja&tl=en&u=http%3A%2F%2Fwww.n...pentax645d.php

Since like me you probably do not mind little bit loss of sharpness in exchange for DOF at f/16 and f/22, you may find the results there with these aperture settings very usable, especially after careful lens correction (CA and distortion) in Photoshop and sharpening, while ideally these should have been done in RAW Developer or LightRoom.
01-07-2011, 11:41 AM   #4
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QuoteOriginally posted by leping Quote
See my posts days ago (page 3 on 33-55 and page 2 on the 35mm):

https://www.pentaxforums.com/forums/pentax-medium-format-645-6x7-645d/126674-...ns-645d-3.html

and an "aperture series" full resolution JPEGs from a 33-55 at 33mm from Japan:

?????6?????????????PENTAX645D????????????????????
Google Translate

Since like me you probably do not mind little bit loss of sharpness in exchange for DOF at f/16 and f/22, you may find the results there with these aperture settings very usable, especially after careful lens correction (CA and distortion) in Photoshop and sharpening, while ideally these should have been done in RAW Developer or LightRoom.
Yes, I actually read that before posting this thread and, frankly, I was quite happy with it even at f/32. But, I was just trying to delve a little deeper into the topic.

And, yes, hyperfocal distance shooting is different than shooting at a test chart, too. And, you're kind of focusing at a "calculated" polnt in space. So, I was just looking for practical experience with other people shooting landscapes and seing how it works in the real world.

BTW, is Photoshop CS5's ACR as good as Lightroom's? Is it the same or are there some differences? Also, with my Nikon D300, if I would bring the NEF files into the Nikon Capture NX software, it would do a fantastic job removing CA, virutally perfect. It seemed to do it non-linearly. And, I wasn't even using a Nikon lens. I was using a Tamron 12-24mm! However, when I'd try removing CA with PSCS5 ACR, you have to do it manually, which fixes some spots, but then screws up others. So, as for the Pentax 645D, can PS ACR automatically remove the CA for Pentax 645D RAW files (DNG's, for instance)?

Thanks,
Mike


Last edited by chicagonature; 01-07-2011 at 12:01 PM.
01-08-2011, 10:32 AM   #5
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Mike I will be doing some test shots today with my 45mm fa lens at f11-16,
I personally think f16 I the max on the 645d in my limited tests I have done.
F22 looks to soft. But maybe on a slower lens it maybe ok.
I know on my old H3D39 full frame 39mp hassy f22 was ok but the sensor size was bigger meaning bigger pixels.
To me just having more pixels without also having sharpness is a waste od money and I do hope pentax gets there act together in terms of lens for the 645d.
I woul be happy with a new design 35mm, 45mm, and 75' which I know have been getting good results but my copy 75mm fa is not so great so I am frustrated.
I am not a big fan of buying used lenses on eBay, even if they offer a 7 day return policy, to me the problem is all these lenses being sold right now probably do work excellent on the older 645n film cameras but one you put them on a 645d its a whole new ball game so buying a used lens off eBay or anywhere in that matter id you get the lens which is even in mint condition the seller will come back and say "the lens works perfect on my 645n" see my point.. It's a total crap shoot.
There a 33-55 on eBay now, wow I would love to have this lens but to me you are taking a big risk, because odds are it may not perform well and then your stuck.

Well thats my take on it.
To bad, IMHO the 645d smokes either the mamiya / phase or the hassy h4d 40 but the lens issue... Huge stumbling block.

Steven
01-08-2011, 11:57 AM   #6
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QuoteOriginally posted by kuau Quote
Mike I will be doing some test shots today with my 45mm fa lens at f11-16,
I personally think f16 I the max on the 645d in my limited tests I have done.
F22 looks to soft. But maybe on a slower lens it maybe ok.
I know on my old H3D39 full frame 39mp hassy f22 was ok but the sensor size was bigger meaning bigger pixels.
To me just having more pixels without also having sharpness is a waste od money and I do hope pentax gets there act together in terms of lens for the 645d.
I woul be happy with a new design 35mm, 45mm, and 75' which I know have been getting good results but my copy 75mm fa is not so great so I am frustrated.
I am not a big fan of buying used lenses on eBay, even if they offer a 7 day return policy, to me the problem is all these lenses being sold right now probably do work excellent on the older 645n film cameras but one you put them on a 645d its a whole new ball game so buying a used lens off eBay or anywhere in that matter id you get the lens which is even in mint condition the seller will come back and say "the lens works perfect on my 645n" see my point.. It's a total crap shoot.
There a 33-55 on eBay now, wow I would love to have this lens but to me you are taking a big risk, because odds are it may not perform well and then your stuck.

Well thats my take on it.
To bad, IMHO the 645d smokes either the mamiya / phase or the hassy h4d 40 but the lens issue... Huge stumbling block.

Steven
Firstly, diffraction becoming obvious beyond F:16 is a fact of physics and visible on the 645 film camera as well.
Secondly, the fact that you got a lemon of a 75mm on e-bay is hardly Pentax fault. This lens, which is not grounbreakingly superb but merely good, has higher resolution than any digital sensor.
01-08-2011, 12:05 PM   #7
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QuoteOriginally posted by chicagonature Quote
I've been shooting with a 645NII and the 33-55mm lens for years. I can easily print great looking 24x33" prints and even 43x56" prints on my Epson 9800. Mike
The 33-55 is the weakest lens in the 645 line-up. It is rather unique and extreme lens for MF but still affordable for what it is. It is also my most used lens; I rarely shoot at wider apertures than F:13. At F:22 and F:32 all lenses are equal anyway.
01-08-2011, 02:01 PM   #8
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I know about diffraction and that supposedly there are certain limits related to what is acceptably sharp. But, I make very nice looking large prints using the 33mm lens shot at f/32 on my 645NII film camera. So, I'm just trying to figure out how the 645D compare in a landscape photography, hyperfocal distance type situation at f/18 and f/25 (equivalent to f/22 and f/32 based on the crop factor).

As LEPING (above) states, "Since like me you probably do not mind little bit loss of sharpness in exchange for DOF at f/16 and f/22, you may find the results there with these aperture settings very usable, especially after careful lens correction (CA and distortion) in Photoshop and sharpening, while ideally these should have been done in RAW Developer or LightRoom."

I remember people in some forum saying stuff like, "Well, my 6x7 images transparencies only look sharp when blown up to a 16x24" print. Huh? And, I spoke with a Schneider engineer who said that Schneider digital lenses start failing at f/8 due to diffraction. Man, I thought I was a perfectionist! So, I'm just hoping for a realistic comparison (before sharpening is applied).

Thanks!

01-08-2011, 02:04 PM   #9
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QuoteOriginally posted by chicagonature Quote
I know about diffraction and that supposedly there are certain limits related to what is acceptably sharp. But, I make very nice looking large prints using the 33mm lens shot at f/32 on my 645NII film camera. So, I'm just trying to figure out how the 645D compare in a landscape photography, hyperfocal distance type situation at f/18 and f/25 (equivalent to f/22 and f/32 based on the crop factor).
I agree with you and I suspect that much of the dissatisfaction comes from excessive pixelpeeping (everything is not as sharp as everything else) instead of real life prints....
01-08-2011, 02:05 PM   #10
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QuoteOriginally posted by Pål Jensen Quote
Firstly, diffraction becoming obvious beyond F:16 is a fact of physics and visible on the 645 film camera as well.
Secondly, the fact that you got a lemon of a 75mm on e-bay is hardly Pentax fault. This lens, which is not grounbreakingly superb but merely good, has higher resolution than any digital sensor.
I never said it was pentad fault, I was just stating that it's a total crap shoot wen buying used lenses from anyone and buyer beware.

I really like the 75mm FOV on the 645D, If anyone can tell me where i can buy a new one, with a pentad warranty I would gladly pay for it.

Steven
01-08-2011, 02:48 PM   #11
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Update:
Just got back form shooting for about 40 minutes.
Looked at all my dng's and I was wrong about my 75mm FA, It performing fine. AF, etc. Sharp as nails.
Thank god....
Unfortunately I can not say the same thing about the 45mm FA, Should have listened to Diglloyd, The center 2/3 of the image very nice, but off to the corners yuk, fuzzy and bad purple fringing. I can correct the fringing, but I can't sharpen up the other 1/3 of the frame. Bummer. I so wanted the 45mm FA to perform well.
FYI, shooting technique, solid, 2 sec mirror up delay, tripod, shoot a whole series from f8 - f22, the corners never improved. If anyone wants to look at them I can email you my ftp site. I don't want to post it publicly.
steven
01-08-2011, 03:01 PM   #12
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QuoteOriginally posted by kuau Quote
Unfortunately I can not say the same thing about the 45mm FA, Should have listened to Diglloyd, The center 2/3 of the image very nice, but off to the corners yuk, fuzzy and bad purple fringing. I can correct the fringing, but I can't sharpen up the other 1/3 of the frame. Bummer. I so wanted the 45mm FA to perform well. [/email]
The FA645 45/2.8 is not one of Pentax best lenses. I think it is the worst Pentax 645 prime judgeng from the sample I once owned; the FA645 45-85/4.5 is much better and even the 33-55 display less flare!
01-09-2011, 06:49 PM   #13
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QuoteOriginally posted by Pål Jensen Quote
The FA645 45/2.8 is not one of Pentax best lenses. I think it is the worst Pentax 645 prime judgeng from the sample I once owned; the FA645 45-85/4.5 is much better and even the 33-55 display less flare!
Pål:

I agree, sold my 45 FA years ago.
For something completely off topic: Bjorn Daehlie is an athelete I really enjoyed watching. Is he still prominent in Norway?
01-10-2011, 05:38 PM   #14
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Was he a Langlaufer?
01-10-2011, 07:22 PM   #15
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So, back to the business of photography. I'm still hoping to find out more about people's experiences wth wide angle lens on the new 645D body and how the results compares to the film pictures.

Thanks!
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