Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-02-2016, 02:20 PM   #1366
Pentaxian




Join Date: Feb 2015
Photos: Albums
Posts: 3,224
QuoteOriginally posted by Nicolas06 Quote
Pentax explained how they optimized their FF to use the right substrate, reduce noise and get the best possible results.
According to recent publications from ISSCC, and patent here: https://www.google.com/patents/US6853044. Biasing the sensor substrate with other than 0V (refer to latest ISSCC design conference papers) allows more dynamic range without exceeding the breakdown voltage of the PIN junctions. I think it was likely implemented on some of the latest APSC DSLR. But if the same technique is applied to FF sensors, then you are back to square 1, the difference between the better APSC sensor and the better FF sensor remains the same.

05-02-2016, 02:20 PM   #1367
Pentaxian
D1N0's Avatar

Join Date: May 2012
Location: ---
Photos: Gallery
Posts: 4,088
The vignetting on the 50-135 is rectangular. Why is that? I think it is full frame but there is something in the way. uhhhh huhhhh.
05-02-2016, 02:25 PM   #1368
Moderator
Site Supporter
MarkJerling's Avatar

Join Date: May 2012
Location: Wairarapa, New Zealand
Photos: Gallery | Albums
Posts: 5,957
QuoteOriginally posted by D1N0 Quote
The vignetting on the 50-135 is rectangular. Why is that? I think it is full frame but there is something in the way. uhhhh huhhhh.
The lens hood?
05-02-2016, 02:32 PM   #1369
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 9,093
QuoteOriginally posted by MarkJerling Quote
The lens hood?
I was about to ask the same question.

It is not an FF lens, that's for sure.

05-02-2016, 02:56 PM   #1370
Pentaxian
thibs's Avatar

Join Date: Jun 2007
Location: Belgium
Photos: Albums
Posts: 5,221
Some food for thoughts: Fuji uses Sony sensors and changes the filter to a non Bayer one but the sensor itself is usual Sony. See the price difference?

Now let's make a custom Pentax only Aps-H and ask ourselves why on earth does it cost 2x a FF sensor price.

The FF adds on ApsH and throws nothing. Furthermore it adds little (reality) and stupidly nothing (marketing-wise) and lastly, a lot of APS lenses would NOT be compatible. Yeah, SR here we are.

What an excellent way of losing on EVERY points.
05-02-2016, 03:50 PM   #1371
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,863
QuoteOriginally posted by Nicolas06 Quote
There no constant or law or whatever that explain that sensor performance variation thanks to different technologies have to be +/-0.5EV.
Correct.

0.5EV was a ballpark figure which seems to be rather accurate today (wrt 18% gray noise). It used to be larger in the past and will aproach 0EV in the future, as we approach the limits of physical feasibility.

And as I explained some time ago, please forget that "substrate" nonsense.
05-02-2016, 03:58 PM   #1372
Pentaxian
D1N0's Avatar

Join Date: May 2012
Location: ---
Photos: Gallery
Posts: 4,088
QuoteOriginally posted by MarkJerling Quote
The lens hood?
Doesn't look like the hood to me:
05-02-2016, 04:32 PM   #1373
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,676
QuoteOriginally posted by D1N0 Quote
Doesn't look like the hood to me:
Does t have a baffle at the rear of the lens?

http://www.photoclubalpha.com/wp-content/uploads/2008/05/70300gmount.jpg

05-02-2016, 05:05 PM   #1374
Loyal Site Supporter
Mikesul's Avatar

Join Date: Sep 2009
Location: Phoenix, AZ
Posts: 2,601
The DA*50-135 is definitely not a full frame lens. There probably is a baffle on the rear end.
05-02-2016, 06:01 PM   #1375
Moderator
Site Supporter
MarkJerling's Avatar

Join Date: May 2012
Location: Wairarapa, New Zealand
Photos: Gallery | Albums
Posts: 5,957
QuoteOriginally posted by Winder Quote
QuoteOriginally posted by Mikesul Quote
The DA*50-135 is definitely not a full frame lens. There probably is a baffle on the rear end.
I do not believe the DA 50-135 has a baffle at the rear. And, without the lens hood, the vignetting will be regular round. That lens does not have a huge amount of vignetting, so - most likely - it's that lovely deep hood on the front.
05-02-2016, 06:02 PM   #1376
Moderator
Site Supporter
MarkJerling's Avatar

Join Date: May 2012
Location: Wairarapa, New Zealand
Photos: Gallery | Albums
Posts: 5,957
QuoteOriginally posted by D1N0 Quote
Doesn't look like the hood to me:
Looks like the hood to me.
05-02-2016, 10:44 PM   #1377
Pentaxian




Join Date: Nov 2013
Posts: 4,621
QuoteOriginally posted by biz-engineer Quote
According to recent publications from ISSCC, and patent here: https://www.google.com/patents/US6853044. Biasing the sensor substrate with other than 0V (refer to latest ISSCC design conference papers) allows more dynamic range without exceeding the breakdown voltage of the PIN junctions. I think it was likely implemented on some of the latest APSC DSLR. But if the same technique is applied to FF sensors, then you are back to square 1, the difference between the better APSC sensor and the better FF sensor remains the same.
And that the point, I would like we go back to the 1.22EV difference on the next Pentax APSC flagship against the best FF and not 1.75 to 2.6EV depending of the measurement you take: dynamic range or Snr18%. Basically there 0.5 to 1.4Ev to take depending of what you measure. For many people there chances it look like a full Ev difference in practical terms.

And this I would quite appreciate to take, thanks. I have nothing against the theoretical difference between APSC and FF, I don't especially want an FF neither because of size/weight. What I'd like is camera that perform better that's all. And I see that theses days recent APSC camera for Pentax could do it.
05-02-2016, 10:59 PM - 1 Like   #1378
Site Supporter
Zygonyx's Avatar

Join Date: Jun 2011
Location: Ile de France
Posts: 3,019
QuoteOriginally posted by D1N0 Quote
Doesn't look like the hood to me:
Just crop to APS-H
05-03-2016, 12:38 AM   #1379
bxf
Site Supporter
bxf's Avatar

Join Date: Jul 2010
Location: Lisbon area
Posts: 1,094
QuoteOriginally posted by Zygonyx Quote
Just crop to APS-H
This ignores the theoretical advantages of APS-H viz-a-viz FF:

1. smaller, therefore cheaper sensor
2. smaller sensor, therefore smaller, lighter body
05-03-2016, 12:56 AM   #1380
Site Supporter
Zygonyx's Avatar

Join Date: Jun 2011
Location: Ile de France
Posts: 3,019
Yes, but the cruel fact is : no APS-H sensor in K-mount, yet
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!
auto, base, camera, company, compression, d810, design, dr, electrons, fa, hardware, iso, k-1, k-3, lenses, pentax, pentax body, pentax k-1, pentax news, pentax rumors, photos, pre-order, risk, sensor, specifications, timelapse, trip, vs
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax K-3 II Officially Announced Adam Pentax News and Rumors 1015 07-03-2015 10:55 PM
Pentax K-S2 Officially Announced Adam Pentax K-S1 & K-S2 12 05-23-2015 06:49 AM
Pentax K-30 Officially Announced! Adam Pentax News and Rumors 245 09-12-2012 08:32 PM
Pentax K-5 Officially Announced Adam Pentax News and Rumors 533 03-06-2012 05:45 AM
K-5 Firmware 1.02 Officially Announced Ole Pentax K-5 50 01-20-2011 10:05 PM



All times are GMT -7. The time now is 07:52 PM. | 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