Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-06-2016, 04:34 PM   #46
Pentaxian
dcBear78's Avatar

Join Date: Jan 2013
Location: Gladstone, QLD
Photos: Gallery
Posts: 819
One thing I noticed when going from Pentax to my D810 was much much less chromatic aberrations and the complete absence of purple fringing I was so used to with my FA Ltds. None across any of my lenses (Tamron 15-30, 24-70, 70-200 and Sigma Art 50 & 35).

I'm guessing this is the benefit of modern designed lenses.

03-06-2016, 05:13 PM   #47
Pentaxian
traderdrew's Avatar

Join Date: Jun 2010
Location: Florida
Photos: Gallery | Albums
Posts: 570
QuoteOriginally posted by slip Quote
a lens that used to be sharp on my K5iis has a slight blur on the K3 due to being able to zoom into the details closer with the higher resolution. I would think that the K1 will be brutal for focusing errors. thoughts?

Randy
I would always align my camera with my lens with any lens at or over 200mm. I can get sharper images with my K-3 over my K-5 any day with the Sigma 500mm f/4.5. I had to adjust auto focus fine tune to a +4 on the K-3. On the K-5 I didn't have to adjust it because my tests showed it was aligned well.

I suspect (not necessarily you) that some people aquire a new lens but their alignment could be way off and they blame it on the lens. Both lenses and bodies have manufacturing tolerances and are not perfectly made to minute measurements much less perfectly made for each other.

Last edited by traderdrew; 03-06-2016 at 05:31 PM.
03-06-2016, 05:34 PM   #48
Site Supporter
slip's Avatar

Join Date: Oct 2006
Location: 2 hours north of toronto ontario canada
Photos: Gallery | Albums
Posts: 3,515
Original Poster
Why are there multiple posting of the same replies?
When taking about "rebadged" Tamron lenes, people forget it is quite common for manufacturing to make products for others... the design is likely a formula that Pentax required. The only thing different between certain Tamron lenses and Pentax lens is were they are manufactured. Tamron quality would be to the standards of Pentax

Randy
03-06-2016, 05:51 PM   #49
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 23,715
QuoteQuote:
You made that up. You lied, which makes your personal attacks and claims that I am misleading even more ridiculous.
Life is too short dude. we're done.

O won't waste time on some dude who completely destroys the gist of the thread over some little lapse of memory. The point I made, this has nothing to do with. A small correction would have been sufficient. Calling me a liar, what a baby. You forgot to say "pants on fire. " You can replay, you've made it to my ignore list, should have happened long ago.


Last edited by normhead; 03-06-2016 at 06:03 PM.
03-06-2016, 05:53 PM   #50
Pentaxian
traderdrew's Avatar

Join Date: Jun 2010
Location: Florida
Photos: Gallery | Albums
Posts: 570
QuoteOriginally posted by slip Quote
Why are there multiple posting of the same replies?
When taking about "rebadged" Tamron lenes, people forget it is quite common for manufacturing to make products for others... the design is likely a formula that Pentax required. The only thing different between certain Tamron lenses and Pentax lens is were they are manufactured. Tamron quality would be to the standards of Pentax

Randy
I looked for my post I made earlier today and I didn't see it posted for some reason so I rephrased what I stated. Now I see my earlier post.
03-06-2016, 08:32 PM   #51
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 26,158
QuoteOriginally posted by dcBear78 Quote
I'm guessing this is the benefit of modern designed lenses.
Less apparent LaCA is the result of the larger sensor. Less PF would be due to some other sensor factor in much the same way that PF* is not present on film.


Steve

* Unless you are talking about LoCA. It and Purple Fringing are two different phenomena with similar appearance. LoCA might appear less apparent on your D810 for the same that LaCA is less apparent. Sensor size counts.
03-06-2016, 10:11 PM   #52
Senior Member




Join Date: Mar 2013
Location: So-central, MI / Central, IN
Posts: 172
After watching and reading as many reviews as I could find (to date) regarding the K-1 it has become quite obvious to me that many online 'reviewers' don't have a very solid foundation in the basic physics of photography. Nor are they even capable (or perhaps just willing) to read and understand the manufacturers specification and feature set for the product they are reviewing. At the very least, they seem more caught up in and concerned with their own ego and close minded opinionated view points. I would not recommend investing any confidence in their shallow claims or posturing.

Of course there are a few select reviewers who make genuine effort to be honestly informative, accurate and objective in their reviews.

There are members in this forum and others elsewhere on the web who regularly use film era lenses on digital sensor cameras both APSC as well as 35mm full frame. They report very favorable results in resolution, rendering character and color with many lenses. Typically more CA and fringing occurs than with modern digital era lenses due to physical differences between film and digital sensors, but these can readily be corrected in post processing.
03-07-2016, 12:00 AM   #53
Veteran Member




Join Date: Jul 2008
Location: Sweden, Umea
Posts: 869
QuoteOriginally posted by MJSfoto1956 Quote
Early adopters of the D800 had the same surprise: they need to up their technique to take advantage of the improved precision instrument they were using. And much of it was indeed technique and less the lenses they were using.

Michael

Well, many of the first adapters of the d800 was former d700 owner. They went from 12mp to36 mp. Even those moving from d3x 24mp had 50% increase of pixel density.
And you also had the famous left/right side inconsistance in focusing on the d800

03-07-2016, 12:24 AM - 1 Like   #54
Site Supporter




Join Date: Feb 2015
Photos: Albums
Posts: 2,808
QuoteOriginally posted by clackers Quote
What's your logic?
Always skeptical? My logic is technical: the smaller the pixels, the more accurate focus needs to be to get the maximum sharpness at the focus plane. Also confirmed in practice: 5% focus shift on a K-3 is very visible, the same amount on a K5 is almost invisible, considering relative sharpness and lack of OAA on the K-3. You'll argue that ff has shallower DoF, hence more difficult to AF. But think about it for a minute...shallower DoF and more discernible phase differences for the AF module. So, in short, the problem isn't the format, the problem is due to pixel density. The higher the pixel density, the more accurate everything needs to be.

QuoteOriginally posted by clackers Quote
Both methods of AF (CD and PD) benefit from more resolution.
I think CD AF would benefit from more resolution of the image sensor, but not true for PDAF. PDAF is independent from the image sensor, so, if the pixel pitch is smaller , an small error of PDAF result is higher relative pixel blur on a higher resolution sensor.
03-07-2016, 01:32 AM   #55
Senior Member




Join Date: Jan 2013
Location: West Sussex
Posts: 106
I realised decent old lenses would never be a limiting factor the day I put an SMC 50mm F1.7 M series lens on my K3!!

End of argument... The darned thing gets bloody close to my Pentax 77mm F1.8 limited and Pentax D-FA 100mm F2.8 macro, themselves regarded as in the upper echelons of Pentax lenses.

The whole argumant about old lenses not working well is bunkum - as long as they are good lenses. Cheap consumer orientated lenses are not all brilliant. I have a Tokina AT-X 80-400 that is no match for my Tamron 70-200 F2.8...

jonlg
03-07-2016, 01:36 AM   #56
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 7,685
QuoteOriginally posted by biz-engineer Quote
Always skeptical? .
Yep. ☺


QuoteOriginally posted by biz-engineer Quote
I think CD AF would benefit from more resolution of the image sensor, but not true for PDAF.
Fair enough.
03-07-2016, 04:15 AM   #57
Pentaxian
dcBear78's Avatar

Join Date: Jan 2013
Location: Gladstone, QLD
Photos: Gallery
Posts: 819
QuoteOriginally posted by stevebrot Quote
Less apparent LaCA is the result of the larger sensor. Less PF would be due to some other sensor factor in much the same way that PF* is not present on film.


Steve

* Unless you are talking about LoCA. It and Purple Fringing are two different phenomena with similar appearance. LoCA might appear less apparent on your D810 for the same that LaCA is less apparent. Sensor size counts.

Whatever it is I have not seen one single pixel of green or purple with these lenses on my D810. Be that due to the lenses or sensor I'm not sure.
03-07-2016, 04:53 AM - 1 Like   #58
Pentaxian
noelpolar's Avatar

Join Date: Oct 2013
Location: Goolwa, SA
Posts: 3,001
QuoteOriginally posted by IgorZ Quote
I heard two reviewers say that old lenses are not going to be sharp on K-1, but I don't know authoritative they are, and whether they spoke from experience, or theory
Confucius says... "Some reviewers lack half the clarity of an old K lens".... Confucius went on to add "balsam separation seems to plague their brains somewhat when reviewing Pentax products"
03-07-2016, 10:56 AM   #59
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,284
QuoteOriginally posted by dcBear78 Quote
Whatever it is I have not seen one single pixel of green or purple with these lenses on my D810. Be that due to the lenses or sensor I'm not sure.
Old lenses on Pentax and new lenses on the Nikon perhaps? Designed for digital lenses should do a better job on this, though not all of them do.
03-07-2016, 11:36 AM   #60
Site Supporter
slip's Avatar

Join Date: Oct 2006
Location: 2 hours north of toronto ontario canada
Photos: Gallery | Albums
Posts: 3,515
Original Poster
QuoteOriginally posted by biz-engineer Quote
Always skeptical? My logic is technical: the smaller the pixels, the more accurate focus needs to be to get the maximum sharpness at the focus plane. Also confirmed in practice: 5% focus shift on a K-3 is very visible, the same amount on a K5 is almost invisible, considering relative sharpness and lack of OAA on the K-3. You'll argue that ff has shallower DoF, hence more difficult to AF. But think about it for a minute...shallower DoF and more discernible phase differences for the AF module. So, in short, the problem isn't the format, the problem is due to pixel density. The higher the pixel density, the more accurate everything needs to be.


I think CD AF would benefit from more resolution of the image sensor, but not true for PDAF. PDAF is independent from the image sensor, so, if the pixel pitch is smaller , an small error of PDAF result is higher relative pixel blur on a higher resolution sensor.
Good explanation. The reason I see a slight blur on my K3 compared to my K5iis is the K3 zooms in closer at 100% viewing. The K5iis would pixelate instead

Randy
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!
24x36mm, aperture, application, approach, brand, car, corner, corners, detail, dof, full-frame, kodachrome, lens, lenses, loupe, pentax, picture, post, resolution, scans, screen, sharpness, slide, slides, sports
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Be careful what you sell sam-joseph Pentax SLR Lens Discussion 3 12-31-2013 08:30 AM
Nature Be careful what you say... gjtoth Post Your Photos! 3 04-13-2013 01:01 PM
Be Careful What You Photograph! grhazelton Photographic Industry and Professionals 17 02-26-2011 03:47 PM
Nature Be careful! It's looking at YOU!!! Rense Post Your Photos! 4 05-24-2010 03:06 PM
Be careful what you're shooting. dws1117 General Talk 3 01-30-2009 09:59 AM



All times are GMT -7. The time now is 06:06 AM. | See also: NikonForums.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