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Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the 645D

tsjanik

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Tsjanik, in my experience the SMC 67 55 is an extraordinary lens. It is not possible to see any difference with any other lens because it out resolves (at least my copy) the 645d center to corner full open.
Sergio
Serigo, yes the 67 55mm has an outstanding reputation, and I am not saying that is undeserved but rather that the 645 55mm is underrated and that at least for my copies of these lenses, the 645 lens has less purple fringing and maybe a little more contrast.

Tom
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Dave: Thank you so much for the tremendous amount of work obviously put in to this. I have printed this out, and it will become my "Bible" for 645D lenses!
Again....thanks
Dave in NJ
Dave, thank you ever so much for your kind words...they're greatly appreciated! Your contributions in providing both your experiences with the 645D and especially your posted images, have always been an inspiration. Thanks again!

Dave (D&A)
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Serigo, yes the 67 55mm has an outstanding reputation, and I am not saying that is undeserved but rather that the 645 55mm is underrated and that at least for my copies of these lenses, the 645 lens has less purple fringing and maybe a little more contrast.

Tom
Hi Sergio and Tom,

Both of your personal experiences and images with Pentax 67 lenses on the 645D illustrate the similarities of issues encountered, are much akin to those I posted with regards to Pentax 645 lenses. Namely these were film era lenses and the presumption is that adjument and acceptable tolerance in lens performance prior toleaving the factory, had considerable acceptable variation for their intended use with cameras at the time of manufacture.

Some lenses like the Pentax 120 f4 645 macro were extremely consistent, while others not so much. When a "good" lens sample is found for many of these Pentax lenses, we all have been impressed with their performance on the 645D.

Dave (D&A)
 

gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

You are quite welcome, Dave. You always seem to go out of your way to say something positive to other people's posts. I am 75 years old, in my day that was referred to as being a gentleman, which you are.
Best regards from cool, foggy, Rainey NJ
Dave in NJ
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

You are quite welcome, Dave. You always seem to go out of your way to say something positive to other people's posts. I am 75 years old, in my day that was referred to as being a gentleman, which you are.
Best regards from cool, foggy, Rainey NJ
Dave in NJ
I feel we have a great bunch of people here, always willing to both praise and provide constructive criticism. Both are important for making evaluations and learning. Thanks!

Dave (D&A)
 

rparmar

New member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Dave, thanks for such an incredible resource. My 645 experience is limited but some day that might change. When it does, this will be especially useful!
 

tsjanik

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

I feel we have a great bunch of people here, always willing to both praise and provide constructive criticism. Both are important for making evaluations and learning. Thanks!

Dave (D&A)
Right you are Dave, this is a great forum. In contrast, I noticed your post on another forum where the replies are not just unappreciative but boderline hostile.

Tom
 
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gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Right you are Dave, this is a great forum. In conrast, I noticed your post on another forum where the replies are not just unappreciative but boderline hostile.

Tom
Yes Tom, I saw them also. I think some people lose their manners as soon as they go on-line. There was another contributor over there that did a ton of early work and evaluations when the 645D first came out (he imported one from Japan). He posted his findings, and to say the least, the responces were unappreciated, and rude. "No good deed goes unpunished"
Dave G
 

Ed Hurst

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Great review and massive amounts of hard work - thank you!

I also have a 645D, and the following lenses:
67 lenses (all latest versions): 55f4, 75f2.8AL, 90f2.8, 90f2.8LS, 105f2.4, 135f4macro, 150f2.8. 165f2.8, 200f4, 300f4EDIF.
645 lenses: 35A (manual focus), 55f2.8DFA (latest digi version), 150FA and the 45-85FA

I also have a Blad 6x6 adaptor (but no such lenses)!

Please let me know if these can of any help to you in further tests (as long as you fly to Australia or tell me how I can do tests for you!).
 

gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Dave (D&A): I also have a near mint 300mm A* lens and "New Old Stock" 1.4X extender. It really is new: box, papers, warranty card, etc. If you would like to borrow both for testing, it would be my pleasure.
Dave in NJ
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

**(Reviosions made to the post below)

Hi Everyone,

I'll attempt to address some of the recent posts above in a single posting, in order to make things a bit more concise:

1. Hi Robin...your kind words are appreciated. I too find when I come across some useful information regarding lenses or equipment...that I might not be shooting with what is being reviewed at the time, but never less, the information down the road often becomes a guide, so that I can make informative choices. Contributions by everyone, like here in GETdpi, truly facilitate this concept.

2. Tom, if I am thinking of the same postings as you were regarding some of the thoughts others posted on a different forum, I'm not sure how hostile they were vs. simply having a different yet strong opinion about certain things. I'm refering to the questioning of aperture I selected for the sweet spot of some of the lenses. The term "sweet spot" as I explained is very subjective....some would say it's the earliest f-stop where max sharpness is generally obtained over most of the frame (ie: max sharpness in the central part of the frame is reached), even though the edges and sides might not be up to the level of the central art of the image. Others, like landscape shooters might say it's the earliest f-stop where optically the lens reaches max sharpness from edge to edge right into the corners. The sweet spot of a given lenses aperture for one type of shooting (or shooters) may differ from those who's objectives in image reproduction is different.

The point is as you well know, differing opinions is both welcome and healthy. Its how we all learn and build up a base of information....but only as long as its done both constructively, with respect for others and of course without malice.

3. Ed, you have some very interesting lenses I'd love to test. I was hoping to get around to the 67 lenses on the 645D, but have to obtain sufficient quantities in order to have a meaningful # of samples. Wow, I'd love to visit Australia and at the moment, don't have my glasses on...did you type you'll be sending me a R/T ticket to your local this week so we can shoot...LOL! I'll keep an eye on my mailbox and start packing (don't I wish)! I appreciate your offer and suggestion and maybe one day I'll get lucky enough to accept. In the meantime your observations with your lenses would be most interesting.

4. Dave (in N.J.)...you have the one lens I've been dying to evaluate and compare to the Fa 300 f4. Namely that's the A* 300 f4. It seems some of the manual focus 645 lenses, whether they are the same optical formula as their Af counterparts or not, may have optical advantages over the same focal lengths in 645 Af lenses. Interestingly, this same thing occurred many years ago when Pentax started making Af 35mm lenses. Many of the older manual focus lenses were optically superior. As you know the MF 35mm f3.5 may have some advantages over the Fa 35mm f3.5...namely less spherical curvature (field curvature). This gives rise to a flatter optical field and therefore, distant landscapes seem to be somewhat sharper across the entire image when compared to the Fa version of the same lens.

Instead of sending the lens, I am hoping that I might be spending a short time (vacation) sometimes this summer in the general vicinity of Cape May. If that happens, who knows, maybe we'll be able to meet up and can do a bit of shooting with both the A*300 f4 and the FA 300 f4 (with and without the 1.4x, which I also have). It would be an interesting comparison.

What I am really after is to get caught in nice steady rainstorm where I can head over to that spot with the bird on the wooden pier which was near a dock....the exact location where you took your astonishing impressive 645D image of such a subject (which you posted not long ago on Getdpi)...and try to emulate the same shot. Of course nothing I photograph will come close to your original! We'll see what happens as simmer approaches.

Thanks all!

Dave (D&A)
 
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D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Just a quick comment. After posting my comments above, I've added/deleated some comments, it case it was read shortly after initially posting. Thanks.

Dave (D&A)
 

gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Dave (D&A): by all means!!!! We love Cape May, in fact we are going there end of this month for our "Cape May fix". Cape May is exit 0 on the Parkway, and we are exit 63, so we are close. I would also love to show you all our favorite photo spots on LBI. My web site has our home phone number.
Best regards
Dave
Web site:
MODERN PICTORIALS.
Ps also have the following manual focus lenses:
35 mm
75mm
120 macro
150mm
200mm
45-85mm
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Wow Dave (in N.J.), that sounds wonderful and very much appreciated. Although I sometimes travel up to the Northeast (on I 95 of course), I only once got to see Cape May for an evening around holiday time years ago. Everything I hear about it and the surrounding areas always soud like a wonderful place to visit and "catch ones breath" for a nice stay. I assume LBI is for Long Beach Island (or something close to that?) That must be a very nice aea too in the summertime I would imagine. As summer approaches, I'll know more regarding travel plans, but all sounds really nice.

What's interesting is you have the manual focus equivelents of many of the Af lenses I have and tested...some being the same optical arrangements, and others somewhat different. Hmmm, and lets, see besides similar lenses you the same camera (645D)...so I wonder then why your images are so often dramatic and spectacular while mine still often need that little something else. :)

Dave (D&A)
 

gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Yes, Dave, LBI is Long Beach Island. The photo you referred to is Polly's Dock, about 4blocks from where we live. It is a real throw back. While bay and beach front mansions go up, Polly's is still unchanged. On my web site I devote an entire page to it (see Polly's Dock page), because I am afraid it will go away to make room for mansions, condos, etc. I have made it a point to photograph it in all kinds of weather.
I also have AF lenses which in some cases duplicate the MF lenses. I have been meaning to shoot them side by side with their equivalent AF lenses, and compare. Alas, even though retired, there just is not enough time in the day for all my interests. Also, do not want to cut into our "Happy Hour " time every evening!
Dave
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

LOL Dave, there "is" never enough hours in the day to really get what we want done....and now I'm finding it doesn't ever change no matter how old one gets! (speaking for myself of course).

Yes, it was your photo I believe at Polly's dock during a rain strom that was one of my favorites of yours (although there were many that I found impressive). I'd love to see that area too (besides Cape May).

When its not so late here, I'll have to go back to your website and read about Polly's dock and the surrounding area. Things change quickly in this world and there is a scene of a lone old storage barn for hay (is that what it's called?) on a rolling hillside...dotted with cattle of course (for this "orginally from NYC" guy to gaze at) while I mavel at the scene and the yearly changes it goes through. The Blue Ridge mountains sets the backdrop. It's a regular stop of mine on the side of the road, to capture it in all it's tranquil splender through all sorts of weather and the change of seasons. Besides an often used informal test image which I then can compare the same images captured, taken with different cameras. I feel at some point that certain changes are in the wind and before I know it, this lovely scene will give way to progress. Thats why so many fo us retrun to our favorite subject, over and over. It's like visting and taking a portrait of an old friend. I bet Polly's Dock has a 1000 different looks depending on the weather, time of day and of course the season and it's always comfortuing to know it's there.

Dave (D&A)
 

gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Dave: Another Icon is "the Causeway Shack" It holds a special place in the hearts of those that used to come to LBI for vacation. It meant "We are almost there". It slowy has fallen down, and it is just about gone. Fortunately I started photographing it way back when, and continue to do so. If you visit my web site there is a special page dedicated to shack images of mine over the years, the page is called Causeway Shack Images. Several were shot a long time ago with my original Pentax 645 and Kodak color negative film. I made 16"x20" color darkroom prints from the negs. I scanned the negs and now have big digital prints.
Sample Images here:
 
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gurtch

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

All four of the above shot with Pentax 645, don't remember which lenses. Back then I had 35mm, 55mm, 75mm and 150mm.
Dave in NJ
 

D&A

Well-known member
Re: Comprehensive Testing: Results & Observations with Pentax 645 Lenses used on the

Hi Dave (in NJ),

Its a bit uncanny...The shack you have been documenting for years in many ways reminds me of the hay barn I described in my post above. I name my files of it "Shed on a Hill". Try to imagine your shack on a hillside with small-moderate mountains in the distance. Almost like that visual image of the house on the hillside from the Sound of Music where the song "The Hills are Alive" starts playing :) . I've photographed my shed for years, though the changing seasons and ever changing landscape. I think most of us who photograph, get attached to some "subject" that represents the passing of "time" and we often stop to document it. I presume for you one of those items is your Shack...for me it's my Shed on the Hill.

Love the last of the four shots with the sunset and birds....stunning Dave!

Like my posting of the lens tests above, where I was delayed, so too am I delayed with posting some 645D images. I hope to address that soon with a few.

There never is enough hours in the day so the first political candidate that promises to extends each day to 28 hours...gets my vote!

Dave (D&A)
 
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L

leping

Guest
The FA 35mm lens "blur zone"

Hi Dave, Yes I am another one independently found the regional "blur zone" problem and very very puzzled since. My feeling is the location of such selective blurring is rondom so I doubt it is related to the resin layer shape imperfections.

What's your recent take on this issue, or have you heard from other people on the problem? Very interesting, and might be related to the way data are read out? If so why only the 35mm FA? Does the A version has the same issue? Could it has relations to what digLloyd just reported on Nikon D800/D800E, the regional "starcasing"?

Anyway a topic needs some deep poking. Thanks again.

Leping

Leping Zha Landscape and Infrared Photography

Pentax FA 645 Lenses

1. FA 35mm f3.5 (28mm) . This very popular lens is an excellent performer under most but not all shooting conditions. It’s performance varies greatly depending on subject distance, f-stop employed and whether the subject is greatly affected by the extensive spherical curvature this lens exhibits primarily at long camera to subject distances. I tested out more samples of this lens (greater than 10), than any other FA lens. The spherical curvature appears small at relatively short distances but quickly grows as the focusing distance increases. At typical landscape distances, many samples display enough spherical curvature so that edges/corners are softer than the central portion of the frame. If one though looks though at the edges/corners (such as the lower right and left ones) that are in the foreground of an infinity focused landscape, these corners are often sharp compared to the upper right and left corners at infinity. This is a result of this spherical curvature. Camera/lens angle and distance to the subject can also greatly influence this. Some barrel distortion is evident with this lens, but nothing that’s not easily correctable in post processing.

** One sometime strange observation I’ve observed with this lens is what I’ll refer to as a “blur zone”. I’ve noticed it in almost all samples (although not in all images with a well defined consistency) an area of the image where all detail in the subject is slightly blurred. Everything above/below and around that zone is sharp and it’s certainly not due to movement of subject (unless a small area of an entire brick wall moved!). I’ve seen this at a wide variety of focus distances. It’s more prevalent at the wider apertures and decreases to an extent when stopped down. It comes and goes and I yet don’t have a handle on a well defined set of parameters to ensure 100% of its appearance. Recently some other FA 35mm f3.5 lens shooters also independently noted this strange anomaly as well as one individual with their MF 35mm A 645 lens. If I had to describe it, it looks like a small group of tree leaves in an entire image of trees together with their leaves, had moved in the wind during exposure....while the rest of the entire mass of trees with their leaves contained in the rest of the image are perfectly sharp. Could it be due to the slightly uneven pouring of the resin used to make the aspherical containing lens element? Purely conjecture at this point and its rarely observed.
 
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