Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-16-2010, 08:55 PM   #1
New Member




Join Date: Oct 2010
Location: Crowley Lake, CA
Posts: 22
Nick Devlin 645D follow-up review on Luminous Landscape

2010 Mini Medium Format Shoot-out

For those of you who remember the argument that testing wasn't too important and 10K should buy perfect quality check out the phase and pentax problems. I agree the problem is misalignment of the sensor.

Nick did a great review using a...wall for his critical test subject.

11-16-2010, 10:40 PM   #2
Loyal Site Supporter
blackcloudbrew's Avatar

Join Date: Mar 2009
Location: Cotati, California USA
Photos: Gallery | Albums
Posts: 3,816
This is a great review, very interesting.
11-16-2010, 10:59 PM   #3
Loyal Site Supporter
Canada_Rockies's Avatar

Join Date: Nov 2007
Location: Sparwood, BC, Canada
Photos: Gallery | Albums
Posts: 9,533
Very interesting link. Thank you!
11-17-2010, 03:04 AM   #4
Loyal Site Supporter
drougge's Avatar

Join Date: Jan 2010
Location: Malmö
Photos: Gallery
Posts: 787
QuoteOriginally posted by claudefiddler Quote
For those of you who remember the argument that testing wasn't too important and 10K should buy perfect quality check out the phase and pentax problems. I agree the problem is misalignment of the sensor.
I don't think he's saying the sensor is misaligned. I think he's saying the camera was not pointed straight at the wall.

11-17-2010, 06:08 AM - 1 Like   #5
Senior Member




Join Date: Oct 2010
Location: Toronto, Canada
Posts: 132
QuoteOriginally posted by drougge Quote
I don't think he's saying the sensor is misaligned. I think he's saying the camera was not pointed straight at the wall.
Thanks for the kind words, glad you enjoyed the write-up.

While I originally blamed sensor-angle, we have added an addendum to the article in which we posit that internal misalignment of the sensor or lens plane is a more likely culprit.

The more I think about this, the more likely I feel that this is the explanation, perhaps operating in conjunction with a failure to achieve perpendicularity to the wall (not a real concern in the real world).

On further reflection, I think it is likeliest that the lens is to blame, at least on my camera, since the fixed 75mm did just fine.

I'm going to reshoot this later this week, with a different camera along as well, just to mess around with this issue.

What this illustrates, however, is just how tight tolerances have to be in the digital world for 'ultimate' image quality to be realized.

Hopefully, however, our article also made it clear that the difference between "ultimate IQ" and what you actually get in a print is so minor to as to make little practical difference in most real-world applications.

Cheers!

- N.
11-17-2010, 07:21 PM   #6
New Member




Join Date: Oct 2010
Location: Crowley Lake, CA
Posts: 22
Original Poster
Nick

If the 75 was sharp in the corners....then the duck wasn't misalignment. Manual focus should have been a piece of cake. Trying to align the camera parallel to the wall is not an option a lot of the time in the real landscape world. As you know. I would have tried a focus bracket on a subject like this.

This is great info and a great pot stir.

Thanks

Claude
11-17-2010, 07:38 PM   #7
Pentaxian
twitch's Avatar

Join Date: Nov 2009
Posts: 4,571
Here's a very interesting article that is relevent: https://www.lensrentals.com/news/2010.03.06/this-lens-is-soft-and-other-facts

QuoteQuote:
with a top quality wide-angle lens on a high resolution sensor, we can perceive a 20 micron difference [in alignment between the lens mount and the sensor], but the manufacturer probably can’t make the part more accurately than +/- 50 microns at a reasonable cost
11-21-2010, 08:03 PM   #8
Senior Member




Join Date: Oct 2010
Location: Toronto, Canada
Posts: 132
Yes, that article is a must-read for anyone contemplating medium format. Kind of sobering...

Thanks again for the link.

- N.

11-25-2010, 03:47 AM   #9
Inactive Account




Join Date: Nov 2010
Posts: 8
Nick,
great review!
I am a Hy6 user and wondering if I might replace my Hy6 with the Pentax. I am a hobby shooter. The IQ of the Hy6 is great, but the AF not.
However a short fast (f3.5 or faster; I like the 110/2.0 Zeiss for my Hy6) telelens would be important to me. Is there any f2.8 or f3.5 AF Pentax lens in the 100-150mm range which you think should work fine on the Pentax? Have you tried?
Do you have any indication which lenses Pentax will bring over the next months/year?
It wouldnt help me to have a great camera body with good AF and then have to MF all the time. For that I could just keep my Sinar.
11-25-2010, 05:35 AM   #10
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,792
QuoteOriginally posted by paratom Quote
Is there any f2.8 or f3.5 AF Pentax lens in the 100-150mm range which you think should work fine on the Pentax? Have you tried?
Pentax does make a SMCP-645 FA150mm f/2.8 that is an excellent lens
11-26-2010, 01:43 AM   #11
Inactive Account




Join Date: Nov 2010
Posts: 8
OK-thank you. This might be the lens for ne.
I just dont know if the new 55m lens would be that usefull and if I should order it as a kit or the camera alone.
But then it would be nice to have one weatherproof lens for bad weather landscape shooting.
Overall I would see a potential kit like 35, 75, 150 + later a Macro and a TS lens.
Dont know yet how the 55 fits in there.
11-26-2010, 02:01 AM   #12
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,792
QuoteOriginally posted by paratom Quote
Overall I would see a potential kit like 35, 75, 150 + later a Macro and a TS lens.
Dont know yet how the 55 fits in there.
Don't forget pentax will be coming out with a 645 D-FA 25mm f/4 lens in the future which will give and effective focal length of 19.5mm in 35mm terms. From the mockup I have seen this lens will feature an internal filter holder not unlike pentax's super telephoto lens series.
11-26-2010, 07:25 AM   #13
Senior Member




Join Date: Oct 2010
Location: Toronto, Canada
Posts: 132
QuoteOriginally posted by paratom Quote
[lang=de]Nick,
great review!
I am a Hy6 user and wondering if I might replace my Hy6 with the Pentax./lang]
To be honest, I would wait. switching MF systems is a very expensive proposition. If your IQ is satisfactory, then I don't see a compelling reason to switch.

The 645D's AF is good, but it's not 35mm-calbre in speed on the older lenses. Perhaps more importantly, I am still working through whether there are some focus precision issues.

The 645D might be the answer, but no need for you to be an early adopter.

- N.
11-26-2010, 10:59 AM   #14
Inactive Account




Join Date: Nov 2010
Posts: 8
QuoteOriginally posted by ndevlin Quote
To be honest, I would wait. switching MF systems is a very expensive proposition. If your IQ is satisfactory, then I don't see a compelling reason to switch.

The 645D's AF is good, but it's not 35mm-calbre in speed on the older lenses. Perhaps more importantly, I am still working through whether there are some focus precision issues.

The 645D might be the answer, but no need for you to be an early adopter.

- N.
Thanks. IQ is perfect with my Hy6 and Sinar back. Its more about size/ AF which is not so accurate and handling.

But you a re probably right that I shall wait - specially it concerns me if some people might have AF issues. I have learned that accurate focus is really critical to take advantage of the bigger sensor.

Thanks for keeping us updated about your experience with the 645D.
Tom
11-26-2010, 04:08 PM   #15
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,792
QuoteOriginally posted by ndevlin Quote
If your IQ is satisfactory, then I don't see a compelling reason to switch.
there is more to a camera than just it's IQ. While at the medium format level IQ is of paramount importance there are things such as interface,ergonomics/control layout, and functionality that are also important. getting the job done is important but if the tool you are using requires idiosyncratic workarounds or otherwise gets in the way, then I see no harm in assessing whether the particular tool can be replaced by one that may better suited to the photographer's requirements. The pentax 645D is undeniably a compelling addition to the realm of medium format DSLR cameras.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, medium format, nick, review
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can't afford the 645D, what is the alternative for landscape. pcarfan Non-Pentax Cameras: Canon, Nikon, etc. 74 01-06-2011 03:25 AM
645D Review bikecoboss Pentax News and Rumors 7 11-16-2010 05:49 PM
The Luminous Landscape 645D review jerrymouse Pentax Medium Format 4 11-14-2010 07:16 AM
Luminous Landscape - 645D Review interested_observer Pentax Medium Format 15 09-08-2010 11:13 PM
http://www.luminous-landscape.com/ needs Pentax K-7 to prove it ogl Pentax News and Rumors 133 10-24-2009 07:50 AM



All times are GMT -7. The time now is 04:28 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top