Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-13-2015, 02:31 PM   #61
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,064
QuoteOriginally posted by jsherman999 Quote
From 1) experience enlarging crops, 2) confirmation from sites like DXOmark and sensorgen and Bill Claff, which also provide a mathematical measure of how much its affected by magnitude of crop.
.
You are mixing* crop with final enlargement. Cropping and magnification are different issues.
The point of larger formats is to be able to print larger.

*The common factor of all the equivalence nonsense - not being sure of the definitions; eg. like mixing focal lenght and angle of view.

02-13-2015, 02:45 PM   #62
Pentaxian
jsherman999's Avatar

Join Date: Dec 2007
Photos: Gallery
Posts: 8,228
QuoteOriginally posted by Pål Jensen Quote
You are mixing* crop with final enlargement. Cropping and magnification are different issues.


.
Enlarging is the default action after cropping.

Does your lightroom catalog present every cropped image in it smaller to you when reviewing/editing images?

Does the LCD on the back of a FF camera show a smaller image after in-camera crop?

Does your printer refuse to print something at 8x10 if it detects it was cropped?

Enlarging a crop is the default action. It's the general case. *Not* enlarging the crop to the same dimensions is the special case, and it's hard to think of common circumstances when you would even choose to do that. And you would have to try to do it, no software or camera or printer keeps your crops small automatically - they all enlarge to the default dimensions - the same dimensions they present/display the un-cropped images at.

DXOMark, Bill Claff, etc all assume the general case and tell you, the photographer, what to expect with your images when you crop and display.

QuoteQuote:
The point of larger formats is to be able to print larger.
Not at all. The point is usually to get better IQ, cleaner output with more DR, and maybe more DOF control. Printing larger is becoming less and less of a reason for people, I think.

.

Last edited by jsherman999; 02-13-2015 at 02:59 PM.
02-14-2015, 10:31 AM   #63
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,064
You are still mixing magnification with format. And stating the obvious as others have pointed out. If you magnify anything twice as much as something else, you get reduced quality. This is true regardless of format. You must keep your definitions straight which you don't do like all equivalence evangelists (there is no true equivalency between formats). Like above where you state that FF give more DOF control; this is patently untrue....
02-14-2015, 10:41 AM   #64
Lens Buying Addict
monochrome's Avatar

Join Date: Mar 2008
Location: Kirkwood (St. Louis) MO
Photos: Gallery | Albums
Posts: 19,483
I wonder if it would help to find some Nikon or Canon Forum and read the posts from a few years ago. They must have gone through the same logical sequence of questions and answers.

02-14-2015, 11:04 AM   #65
Pentaxian




Join Date: Dec 2010
Location: Ontario
Photos: Gallery
Posts: 2,285
QuoteOriginally posted by Pål Jensen Quote
You are still mixing magnification with format.
Nothing is being mixed. If (you crop AND you print at the same size) then (stuff happens). There's clarity about the assumptions made, there should be no confusion.

Maybe the clause (you crop AND you print at the same size) doesn't apply to you, and that's perfectly valid point of view, but it's a pretty reasonable assumption. I'd wager this is how many/most people will view two formats that are this close in size and utility so it's a useful discussion (and pretty clearly not obvious to everyone). I've known several people who moved from aps-c to FF and none of them suddenly started printing at 1.5x the size of their old output, but your experience may vary.
02-14-2015, 11:42 AM   #66
Pentaxian
Designosophy's Avatar

Join Date: Sep 2010
Location: Northeast Philadelphia
Photos: Gallery | Albums
Posts: 1,094
I, for one, hope that the auto crop for APS-C lenses can be turned off. Even if the image circle is smaller than FF, it's still taller than APS-C, which could be useful on occasion.

More importantly, I hope that the camera isn't priced like a 5D or D800.
02-14-2015, 01:13 PM   #67
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,064
QuoteOriginally posted by BrianR Quote
Nothing is being mixed. If (you crop AND you print at the same size) then (stuff happens). There's clarity about the assumptions made, there should be no confusion.

Maybe the clause (you crop AND you print at the same size) doesn't apply to you, and that's perfectly valid point of view, but it's a pretty reasonable assumption. I'd wager this is how many/most people will view two formats that are this close in size and utility so it's a useful discussion (and pretty clearly not obvious to everyone). I've known several people who moved from aps-c to FF and none of them suddenly started printing at 1.5x the size of their old output, but your experience may vary.
The assumption is meaningless cause it assumes that different formats are used in order to be equal. In fact, the opposite is true. Only a fool buy a FF camera i order for it be equivalent to an APS camera. Of course printing at the same size is a valid point of view, but so is not printing at the same size but at the same magnification. Hence, the whole argument is constructed to fit a preconceived opinion. And opinion is all it is. Cropping and final magnification is not the same so you cannot treat as if it was.
Clackers have already explained this above.

Last edited by Pål Jensen; 02-14-2015 at 01:20 PM.
02-14-2015, 02:33 PM   #68
Pentaxian




Join Date: Dec 2010
Location: Ontario
Photos: Gallery
Posts: 2,285
QuoteOriginally posted by Pål Jensen Quote
The assumption is meaningless cause it assumes that different formats are used in order to be equal. In fact, the opposite is true. Only a fool buy a FF camera i order for it be equivalent to an APS camera.
No, it's not implying this at all. Only that you're printing the same size.

QuoteOriginally posted by Pål Jensen Quote
Of course printing at the same size is a valid point of view,
Yes, and arguably this is the most common use.

QuoteOriginally posted by Pål Jensen Quote
but so is not printing at the same size but at the same magnification.
Absolutely. Though it's not how I think most people use different formats (or different crops from a single camera), it's a perfectly valid thing to discuss.

The statement "FF has less noise than APS-C" on it's own is meaningless and possibly confusing if the speaker and listener are taking different views on print size. All I've ever cared about is that the case you're assuming is clearly outlined so everyone's on the same page.

02-14-2015, 05:56 PM   #69
Senior Member
jeff knight's Avatar

Join Date: Jul 2010
Location: Pacific Northwest USA
Posts: 254
This disrespect directed towards forum luminary jsherman999 whose knowledge should be revered, and at the absolute least, respected here, alarms me greatly. Please don't allow our forum to eat it's own at the expense of it's own health.. I, personally, am disappointed.

Jsherman999 probably wont approve of my comments but so what?

Last edited by jeff knight; 02-16-2015 at 02:47 PM.
02-14-2015, 07:18 PM   #70
Pentaxian
jsherman999's Avatar

Join Date: Dec 2007
Photos: Gallery
Posts: 8,228
QuoteOriginally posted by jeff knight Quote
This infantile disrespect directed towards forum luminary jsherman999 whose knowledge should be revered, and at the absolute least, respected here, alarms me greatly. This forum eats it's own at the expense of it's own health. What a bunch of rotters. Clackers and Jensen eat their own young and in their inflexibility, allow no divergence of opinion. I, personally, am disgusted.

Jsherman999 probably wont approve of my comments but so what?
Lol

"Forum Luminary"... or "Insufferable Smarty Pants" ?

.

---------- Post added 02-14-15 at 08:29 PM ----------

QuoteOriginally posted by monochrome Quote
I wonder if it would help to find some Nikon or Canon Forum and read the posts from a few years ago. They must have gone through the same logical sequence of questions and answers.
It would.

Part of my Insufferable Smarty Pants nature about this is because I've been active on those (Nikon FF mostly) forums since 2010 and have been reading about how/why all this format stuff works for the past 5 years.

I've seen myths drop off one by one, including several myths I myself originally held on to, like "larger pixels always mean less image noise," and "cropping changes nothing," and several misunderstandings about DOF.

I got into an argument with Bob Newman about ISO-less cameras (which I slowly, methodically lost) and with Eric Fossum about larger/smaller pixels - I was arguing that larger always = better, based on my vast understanding of... what turned out to be myths. Later on after I came to see things his way I did some googling and found out who he was. I also thought Joseph James was a crank at first... until every practical experiment I did confirmed what he was saying, and I began to really read the math and explanations behind equivalence and take note how every single person who really knew what they were talking about, worked in the industry, etc took it as self-evident. People like Class A and Falk Lumo on this forum have changed my way of looking at and phrasing things as well.

Last edited by jsherman999; 02-14-2015 at 07:30 PM.
02-14-2015, 11:07 PM   #71
Pentaxian




Join Date: May 2009
Location: Ponoka Alberta Canada
Photos: Gallery
Posts: 450
QuoteOriginally posted by jsherman999 Quote
Lol

"Forum Luminary"... or "Insufferable Smarty Pants" ?

.

---------- Post added 02-14-15 at 08:29 PM ----------



It would.

Part of my Insufferable Smarty Pants nature about this is because I've been active on those (Nikon FF mostly) forums since 2010 and have been reading about how/why all this format stuff works for the past 5 years.

I've seen myths drop off one by one, including several myths I myself originally held on to, like "larger pixels always mean less image noise," and "cropping changes nothing," and several misunderstandings about DOF.

I got into an argument with Bob Newman about ISO-less cameras (which I slowly, methodically lost) and with Eric Fossum about larger/smaller pixels - I was arguing that larger always = better, based on my vast understanding of... what turned out to be myths. Later on after I came to see things his way I did some googling and found out who he was. I also thought Joseph James was a crank at first... until every practical experiment I did confirmed what he was saying, and I began to really read the math and explanations behind equivalence and take note how every single person who really knew what they were talking about, worked in the industry, etc took it as self-evident. People like Class A and Falk Lumo on this forum have changed my way of looking at and phrasing things as well.
We all know Eric Fossum knows nothing about sensors
He has the ego as someone who's designed sensors for a living :
02-15-2015, 09:55 PM   #72
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 7,712
QuoteOriginally posted by jsherman999 Quote
Of course it changes nothing at the pixel level. Think that's the third or fourth time I've said that in this thread alone. It doesn't need to for the image quality to be altered by enlargement.

I think you've caught yourself in a contradiction, by the way. If cropping/enlarging can somehow "change resolution", why can it not "change noise"? .

Because SNR is a ratio of signal pixels to noise ones, and pushing them further apart doesn't alter that!

QuoteOriginally posted by jsherman999 Quote

From 1) experience enlarging crops, 2) confirmation from sites like DXOmark and sensorgen and Bill Claff, which also provide a mathematical measure of how much DR is affected by magnitude of crop and subsequent enlargement.

I see you didn't bother to read the links I provided or look at the graphs I provided
.

Oh, I did.


All that irrelevance and not seeing the wood for the trees didn't involve just cropping and scaling, they 'downsampled' and 'normalized' as well - in the case of DXO, attempting to account for the different gain ratings that manufacturers designate as ISO 100 or 200, for example. These are derived and simulated quantities.


One source, like the Clark one you dug up on another thread and dared us all to read, said pixel pitch governs noise performance, contradicting your usual sermon. DXO in their writeup also mention "On the other hand, the same camera has a smaller pixel size and this decreases the SNR."


DXO point out exactly what Brian and I were saying. At an output resolution of 300dpi, they say you only need 8Mp for a 12x8 print - the DX modes of either 36 or 24Mp sensors provide that.

Last edited by clackers; 02-15-2015 at 10:08 PM.
02-15-2015, 10:02 PM   #73
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 7,712
QuoteOriginally posted by jeff knight Quote
This infantile disrespect directed towards forum luminary jsherman999 whose knowledge should be revered, and at the absolute least, respected here, alarms me greatly.

Jeff, nobody gets a leave pass for facts, no matter how many thousand posts they've made, and irregardless of that he's clearly an excellent photographer (much better and more experienced than a relative newbie like myself), whose contributions have included launching many of the Lens Clubs.


If it matters to you, there's common ground - we agree that pixels don't change physical characteristics in cropping, and that scaling beyond resolution output deteriorates quality.


Ad hominem hasn't happened - that would be illogical. Pal, myself and others don't know him outside of his online "Insufferable Smarty Pants" persona.


In fact, I disturbingly think we share a lot of pop culture tastes.

Last edited by clackers; 02-15-2015 at 10:20 PM.
02-16-2015, 12:54 PM   #74
Pentaxian
jsherman999's Avatar

Join Date: Dec 2007
Photos: Gallery
Posts: 8,228
QuoteOriginally posted by clackers Quote
All that irrelevance and not seeing the wood for the trees didn't involve just cropping and scaling, they 'downsampled' and 'normalized' as well.
You speak of 'downsampling' and 'normalizing' as if they also are special cases. They are not - they are the default case.

Every time you export your raw images to jpeg they are downsampled, and things are normalized. Even if you don't do some sort of export first - every time you send directly to a printer, the printer driver does this as well.

If you're printing at native resolution (or even bigger, and up sampling) then the normalization doesn't occur in the same way, but if you are printing cropped images at the same size as native uncropped images, then you are enlarging the cropped images more than the uncropped, and you run into the exact same issue.

Again, this describes what you, the photographer sees when you crop and enlarge.

I'm going to keep pointing you back at the core issue you seem to want to sidestep - unless you, for some reason, want to keep all your crops smaller than the uncropped images in display or print, you will see degradation in both noise and DR in the final image after cropping. No way around that. No way to talk your way out of it.

DXOmark, Bill claff etc describe how much degradation you can expect. They are not lying or making things up. They did the work and measured the results.

.

Last edited by jsherman999; 02-16-2015 at 01:05 PM.
02-16-2015, 02:43 PM   #75
Senior Member
jeff knight's Avatar

Join Date: Jul 2010
Location: Pacific Northwest USA
Posts: 254
Despite my complaints, I am getting useful information from everyone on this.( I have edited my original post.)
Really, does thousands of posts count more than a few. What about full frame camera owners over none? I look forward to more equal balance, Viva Pentax FF .

Last edited by jeff knight; 02-16-2015 at 03:14 PM.
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, 300mm, aps-c, apsc, autofocus, camera, crop, factors, ff, full-frame, image, iso, k-3, lens, mode, nikon, noise, output, pentax, photos, pixels, question, results, sensor, shot, subject
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Crop Factor from a 645 to a K3 APS-C Cary Berman Visitors' Center 31 01-17-2015 09:40 AM
35mm FF vs 35mm crop angle of view on APS-C camera QCdude Pentax SLR Lens Discussion 3 01-26-2014 11:16 AM
Whats the crop factor for a 6x7 lens on a APS-C K-mount camera? 2her0ck Troubleshooting and Beginner Help 8 06-16-2013 11:45 AM
Pentax at P&E2013: FF under development, APS-C compact camera and more Mistral75 Pentax News and Rumors 82 04-30-2013 06:30 AM
Need advice on a 14mm FF versus 18mm APS-C lens CRPhoto Pentax SLR Lens Discussion 8 04-24-2009 09:56 PM



All times are GMT -7. The time now is 01:21 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