DA 28-45mm First Impressions..

MrPhil · 09-11-2014, 12:37 PM

Originally posted by Zygonyx

Gee, an other user that doesn't see or need difference btw 45 and 55mm.
I am taken aback

Not that I don't see or need the difference - I will keep and use my 55mm - but when I am out doing landscape work 95% will be done in the range 28-45 and the other 5% will be at the longer end on the 150mm. The 75mm is the just in case I need something in the middle.

If I found I needed 55mm on the very odd occasions, then I would use 45mm end and crop.

But the 55mm is still very valid - and is another stunner on the 645Z - so very much will be used

jwoodland · 09-11-2014, 01:09 PM

How about filter use at 28mm - anyone have a feel for how thick a filter you can use without any vignetting?

MrPhil · 09-11-2014, 01:24 PM

Not tried it yet - my filter adapter ring for 82mm arrives tomorrow, but I am not expecting any problems.

I will put a Lee Filters wide angle adapter ring on the lens and use my standard Lee filters. I used the same set-up on my Zeiss 21mm with 82mm filters and there was no vignetting - so I assume (but still need to be proved) this set-up will work fine at 28mm end.

Will know after this weekend's shooting :-)

2351HD · 09-11-2014, 04:14 PM

I have set up my lee system on the 28-45.

You can fit a 3 filter combo no problem at 28mm

You can fit a single filter with the lee polarizer on front and it gets the smallest amout of shading in the corners.

But the lee 105 polarizer is quite thick, with maybe another brand it would be just fine.

jwoodland · 09-11-2014, 04:18 PM

Guess I was thinking about screw-in filters - I don't like those giant filter setups, and was trying to figure out how much thickness could be used with a screw in filter without vignetting - if anyone has used one and could report that would be great - thanks!

harklee · 09-11-2014, 06:05 PM - **1 Like**

Guys, here is an update.

So the corner degradation at the wide end (28mm) turns out to be caused by some degree of field curvature, meaning that you can only focus either on the perimeter or on the center of the frame. This is only noticeable at the wide end and is still far better than that of the D-FA 25mm or the FA 35mm. The field curvature can be easily seen by focusing (try manual focus with focus peak on) on different parts of the frame during live view and monitoring the distance meter on the side of the lens. It will change as the focus moves from the center to a corner. However, the live view keeps the aperture wide open, so you are really looking at the field curvature when wide open rather than when stopped down. Regardless, I think the lens is well designed since no wide angle lens is free from some degree of field curvature. I will update the original text accordingly.

The black tapes on the camera are just to prevent it from scratching. I am a landscape guy, and my gear sees some serious use. I just taped some parts of the camera that tend to scratch (based on the years of experience with the 645d).

I tested the lens with a B+W uv filter and a Lee-type adapter ring stacked and they work just fine. Although these are thin wide-angle types so I can't say about regular filters and regular adapter rings.

I will be on a week-long field trip starting tomorrow, so I will post some real-world samples when I am back. Thanks!

jwoodland · 09-11-2014, 06:08 PM

Thanks for the filter report - that helps!

harklee · 09-11-2014, 06:13 PM

Originally posted by Digitalis

Have you found the reversed focus/zoom rings bothersome?

Digitalis, it takes a little bit of getting used to, and yes, I can see some portrait guys getting annoyed. For me, the camera hardly gets off a tripod, and I do lots of focus stacking where having the focus ring closer comes handy.

---------- Post added 09-11-14 at 06:32 PM ----------

Originally posted by Pål Jensen

There has bveen Pentax 645 zoom lenses before. They weight a third or half the weight of the 28-45. The 33-55,which is its predecessor for the full frame 645 format, weigths only 500grams.
I have the 33-55 and the 75mm for my 645NII. They weight 500g and 215g respectively.....

Dear Pål , I am quite a pixel peeper myself, and I tested three different copies of 33-55mm when I first picked up the 645D. I even sent them to the service center in Tokyo to get them individually calibrated. Even after all that, the lenses performed miserably on the corners. And I do not see the point of buying a 50MP camera if the lenses cannot live up to the sensor. I am a rather serious outdoor photographer, and the last thing I want to do is adding more to my already overweight pack. But after testing the new lens, I am almost certain that, to fully utilize the resolving power of the format, the system comes at a price. So as much as I would like to have an ultra-light high-res system (preferably a mirrorless medium format with a shorter flange-back distance and less-retrofocus wide angle lenses), I am afraid that it is not going to happen anytime soon.

robertchow999 · 09-12-2014, 09:57 AM

Originally posted by harklee

The black tapes on the camera are just to prevent it from scratching. I am a landscape guy, and my gear sees some serious use. I just taped some parts of the camera that tend to scratch (based on the years of experience with the 645d).

Some photographers are fond of showing the scratches and wear marks on their gear. I picked up a scrape on the bottom of the edge of 645D grip. I probably got in Utah a few months ago but I don't know how it happened as I normally baby it as if it cost $10,000.

Thomas · 09-15-2014, 08:25 PM

I must admit that the shot posted of the 28-45mm next to the 25mm has me concerned about the diameter of that lens; I'm not sure I can grasp that lens from the side. I really don't understand why the new DA Pentax 645 lenses, with their reduced image circle, have become so much larger than the old FA lenses.

MrPhil · 09-15-2014, 09:45 PM

Actually in use the size isn't a problem. I don't have large hands and using the lens on the camera is fine; it even handholds nicely. What is a problem is the size of the lens in the camera bag, but that is sorted by moving things around and changing the dividers. The feel of the lens is wonderful and it feels really solid and I love the the results, so putting up with the size is a small price to pay.

But no idea why it is as big as it is.

**iCrop** · 09-16-2014, 06:55 AM

Originally posted by Thomas

I really don't understand why the new DA Pentax 645 lenses, with their reduced image circle, have become so much larger than the old FA lenses.

I suspect the built in Shake Reduction.

hsteeves · 09-16-2014, 08:11 PM

Happy. Found that my 77mm Hoya thin cpl will work with a step-down ring. I have to see how many will fit before the lens vignettes.

**Pål Jensen** · 09-20-2014, 06:37 AM

Originally posted by Thomas

I must admit that the shot posted of the 28-45mm next to the 25mm has me concerned about the diameter of that lens; I'm not sure I can grasp that lens from the side. I really don't understand why the new DA Pentax 645 lenses, with their reduced image circle, have become so much larger than the old FA lenses.

I suspect it is the price to pay for digital optimized lenses. New optimized lenses for FF (35mm) is also big; just look at the new 50mm lens from Sigma.
Pancake lenses for APS makes lots of sense in this context....

MrPhil · 09-20-2014, 07:15 AM

As I have found, once you are over the shock of the size and weight, you soon appreciate how well the lens handles and the size/weight become just one of those things. I am now at the stage of no problem carrying it (good backpack), "wow it's is big and heavy" (getting it out of the bag) and finally "this lens is brilliant; love it" (when shooting).

Some things just come in large packages :-)

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09-11-2014, 12:37 PM	#31
MrPhil Forum Member Join Date: Dec 2013 Posts: 62	Originally posted by Zygonyx Gee, an other user that doesn't see or need difference btw 45 and 55mm. I am taken aback Not that I don't see or need the difference - I will keep and use my 55mm - but when I am out doing landscape work 95% will be done in the range 28-45 and the other 5% will be at the longer end on the 150mm. The 75mm is the just in case I need something in the middle. If I found I needed 55mm on the very odd occasions, then I would use 45mm end and crop. But the 55mm is still very valid - and is another stunner on the 645Z - so very much will be used

09-11-2014, 01:09 PM	#32
jwoodland Forum Member Join Date: Dec 2011 Location: Arkansas Posts: 96	How about filter use at 28mm - anyone have a feel for how thick a filter you can use without any vignetting?

09-11-2014, 01:24 PM	#33
MrPhil Forum Member Join Date: Dec 2013 Posts: 62	Not tried it yet - my filter adapter ring for 82mm arrives tomorrow, but I am not expecting any problems. I will put a Lee Filters wide angle adapter ring on the lens and use my standard Lee filters. I used the same set-up on my Zeiss 21mm with 82mm filters and there was no vignetting - so I assume (but still need to be proved) this set-up will work fine at 28mm end. Will know after this weekend's shooting :-)

09-11-2014, 04:14 PM	#34
2351HD Veteran Member Join Date: Apr 2013 Location: Brisbane, Australia Photos: Albums Posts: 750	I have set up my lee system on the 28-45. You can fit a 3 filter combo no problem at 28mm You can fit a single filter with the lee polarizer on front and it gets the smallest amout of shading in the corners. But the lee 105 polarizer is quite thick, with maybe another brand it would be just fine.

09-11-2014, 04:18 PM	#35
jwoodland Forum Member Join Date: Dec 2011 Location: Arkansas Posts: 96	Guess I was thinking about screw-in filters - I don't like those giant filter setups, and was trying to figure out how much thickness could be used with a screw in filter without vignetting - if anyone has used one and could report that would be great - thanks!

09-11-2014, 06:05 PM - 1 Like	#36
harklee Forum Member Join Date: Oct 2010 Location: Sunnyvale, California Posts: 57 Original Poster	Guys, here is an update. So the corner degradation at the wide end (28mm) turns out to be caused by some degree of field curvature, meaning that you can only focus either on the perimeter or on the center of the frame. This is only noticeable at the wide end and is still far better than that of the D-FA 25mm or the FA 35mm. The field curvature can be easily seen by focusing (try manual focus with focus peak on) on different parts of the frame during live view and monitoring the distance meter on the side of the lens. It will change as the focus moves from the center to a corner. However, the live view keeps the aperture wide open, so you are really looking at the field curvature when wide open rather than when stopped down. Regardless, I think the lens is well designed since no wide angle lens is free from some degree of field curvature. I will update the original text accordingly. The black tapes on the camera are just to prevent it from scratching. I am a landscape guy, and my gear sees some serious use. I just taped some parts of the camera that tend to scratch (based on the years of experience with the 645d). I tested the lens with a B+W uv filter and a Lee-type adapter ring stacked and they work just fine. Although these are thin wide-angle types so I can't say about regular filters and regular adapter rings. I will be on a week-long field trip starting tomorrow, so I will post some real-world samples when I am back. Thanks!

09-11-2014, 06:08 PM	#37
jwoodland Forum Member Join Date: Dec 2011 Location: Arkansas Posts: 96	Thanks for the filter report - that helps!

09-11-2014, 06:13 PM	#38
harklee Forum Member Join Date: Oct 2010 Location: Sunnyvale, California Posts: 57 Original Poster	Originally posted by Digitalis Have you found the reversed focus/zoom rings bothersome? Digitalis, it takes a little bit of getting used to, and yes, I can see some portrait guys getting annoyed. For me, the camera hardly gets off a tripod, and I do lots of focus stacking where having the focus ring closer comes handy. ---------- Post added 09-11-14 at 06:32 PM ---------- Originally posted by Pål Jensen There has bveen Pentax 645 zoom lenses before. They weight a third or half the weight of the 28-45. The 33-55,which is its predecessor for the full frame 645 format, weigths only 500grams. I have the 33-55 and the 75mm for my 645NII. They weight 500g and 215g respectively..... Dear Pål , I am quite a pixel peeper myself, and I tested three different copies of 33-55mm when I first picked up the 645D. I even sent them to the service center in Tokyo to get them individually calibrated. Even after all that, the lenses performed miserably on the corners. And I do not see the point of buying a 50MP camera if the lenses cannot live up to the sensor. I am a rather serious outdoor photographer, and the last thing I want to do is adding more to my already overweight pack. But after testing the new lens, I am almost certain that, to fully utilize the resolving power of the format, the system comes at a price. So as much as I would like to have an ultra-light high-res system (preferably a mirrorless medium format with a shorter flange-back distance and less-retrofocus wide angle lenses), I am afraid that it is not going to happen anytime soon.

09-12-2014, 09:57 AM	#39
robertchow999 Senior Member Join Date: Mar 2012 Posts: 117	Originally posted by harklee The black tapes on the camera are just to prevent it from scratching. I am a landscape guy, and my gear sees some serious use. I just taped some parts of the camera that tend to scratch (based on the years of experience with the 645d). Some photographers are fond of showing the scratches and wear marks on their gear. I picked up a scrape on the bottom of the edge of 645D grip. I probably got in Utah a few months ago but I don't know how it happened as I normally baby it as if it cost $10,000.

09-15-2014, 08:25 PM	#40
Thomas Veteran Member Join Date: Feb 2008 Photos: Gallery \| Albums Posts: 434	I must admit that the shot posted of the 28-45mm next to the 25mm has me concerned about the diameter of that lens; I'm not sure I can grasp that lens from the side. I really don't understand why the new DA Pentax 645 lenses, with their reduced image circle, have become so much larger than the old FA lenses.

09-15-2014, 09:45 PM	#41
MrPhil Forum Member Join Date: Dec 2013 Posts: 62	Actually in use the size isn't a problem. I don't have large hands and using the lens on the camera is fine; it even handholds nicely. What is a problem is the size of the lens in the camera bag, but that is sorted by moving things around and changing the dividers. The feel of the lens is wonderful and it feels really solid and I love the the results, so putting up with the size is a small price to pay. But no idea why it is as big as it is.

09-16-2014, 06:55 AM	#42
iCrop Site Supporter Join Date: Mar 2007 Location: Tucson Photos: Gallery Posts: 292	Originally posted by Thomas I really don't understand why the new DA Pentax 645 lenses, with their reduced image circle, have become so much larger than the old FA lenses. I suspect the built in Shake Reduction.

09-16-2014, 08:11 PM	#43
hsteeves Senior Member Join Date: Feb 2010 Location: Saskatchewan Posts: 256	Happy. Found that my 77mm Hoya thin cpl will work with a step-down ring. I have to see how many will fit before the lens vignettes.

09-20-2014, 06:37 AM	#44
Pål Jensen Site Supporter Join Date: Dec 2007 Location: Norway Photos: Albums Posts: 4,371	Originally posted by Thomas I must admit that the shot posted of the 28-45mm next to the 25mm has me concerned about the diameter of that lens; I'm not sure I can grasp that lens from the side. I really don't understand why the new DA Pentax 645 lenses, with their reduced image circle, have become so much larger than the old FA lenses. I suspect it is the price to pay for digital optimized lenses. New optimized lenses for FF (35mm) is also big; just look at the new 50mm lens from Sigma. Pancake lenses for APS makes lots of sense in this context....

09-20-2014, 07:15 AM	#45
MrPhil Forum Member Join Date: Dec 2013 Posts: 62	As I have found, once you are over the shock of the size and weight, you soon appreciate how well the lens handles and the size/weight become just one of those things. I am now at the stage of no problem carrying it (good backpack), "wow it's is big and heavy" (getting it out of the bag) and finally "this lens is brilliant; love it" (when shooting). Some things just come in large packages :-)