Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-17-2014, 09:44 PM - 1 Like   #16
Pentaxian
Wired's Avatar

Join Date: Aug 2009
Location: Edmonton, AB
Photos: Gallery | Albums
Posts: 2,494
Exactly what I thought. Which is why I like 50 on both formats and hate 35 on both formats.....

04-17-2014, 09:58 PM   #17
Site Supporter




Join Date: Feb 2011
Posts: 4,892
QuoteOriginally posted by mtux Quote
Yes, Unfortunately this is true, and you can't expect a 35mm lens to work like a 50mm on FF, not in terms of compression. so, for example portrait shots with 35mm aren't as flattering as 50mm!

With APSC, You are just seeing a smaller part of the whole view!
APS-C at an equivalent focal length, equivalent aperture, and equivalent ISO will produce a picture indistinguishable (except, in practical terms, sharpness, CA, etc) from FF.

I'm not sure exactly what you're comparing, to produce different results? Perhaps you're keeping aperture constant instead of equivalent aperture?
04-17-2014, 10:04 PM   #18
Site Supporter




Join Date: Mar 2010
Location: SW Washington
Posts: 814
QuoteOriginally posted by Wired Quote
On the topic...FOV can matched by changing focal lengths between APSC/35mm. What about compression? I haven't tried it...probably should. But a 50mm lens's compression should be the same no matter which format it's mounted too. Therefore.... using a 35mm to simulate a 50mm FOV would actually put the background further back...in theory? Or is this thinking incorrect?
Perspective is completely dependent on one thing only: distance from subject/background. If you have two objects of the same size, A and B, where A is 10 feet away and B is 20 feet away, A will look twice as big as B. If you move back 10 feet (A is now 20ft, B is now 30ft) A will look 1.5 (30/20) times as big as B. That's all there is to it. No lenses or cameras involved beyond your own two eyes.

You can test this by taking any lens shorter than 50mm, take a shot from the same spot with both the 50mm and the shorter lens, and crop the photo of the shorter lens to the same FOV as the 50mm shot. Besides DOF, they will look the same.

"Compression" is an illusion. Perspective is always constant from a certain position, just you are used to seeing objects at a distance as taking up a small part of your field of vision. When you zoom in you are magnifying to a greater size than you are used to seeing it, so it appears unnatural, even though nothing has actually changed.

Last edited by Cannikin; 04-17-2014 at 10:28 PM.
04-17-2014, 10:29 PM   #19
Veteran Member
mtux's Avatar

Join Date: Apr 2013
Location: Kuala Lumpur, Malaysia
Photos: Gallery | Albums
Posts: 2,388
QuoteOriginally posted by ElJamoquio Quote
I'm not sure exactly what you're comparing, to produce different results? Perhaps you're keeping aperture constant instead of equivalent aperture?
Place a person in front of you, take a head shot with 35mm on APSC, and one with 50mm on FF (or even APSC), check them on monitor. Which one is more flattering!?
I did this test with my wife, and showed photos to her! she's not familiar with these terms, I just asked her which one she prefer!? and the answer was obvious to me.

QuoteOriginally posted by Cannikin Quote
"Compression" is an illusion.
It is not! check these videos by Mike Brown, if you can't see it easily in your viewfinder:


04-17-2014, 11:01 PM   #20
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 7,712
What *am* I doing?

Last edited by clackers; 04-17-2014 at 11:10 PM.
04-17-2014, 11:08 PM - 1 Like   #21
Site Supporter




Join Date: Mar 2010
Location: SW Washington
Posts: 814
QuoteOriginally posted by mtux Quote
Place a person in front of you, take a head shot with 35mm on APSC, and one with 50mm on FF (or even APSC), check them on monitor. Which one is more flattering!?
I did this test with my wife, and showed photos to her! she's not familiar with these terms, I just asked her which one she prefer!? and the answer was obvious to me.
If there is a difference in perspective, it is because you moved. Do the test I described using any two focal lengths you want, and take both shots from exactly the same spot.

I'll do it for you right now:

70mm:


70mm cropped:


130mm:



Do you see how nothing has changed with the perspective going from 70mm to 130mm because I did not move the camera?

Ignore the slight aspect ratio/image size difference, as this is as close as I could crop by hand. The exposure is also a little different, because I stopped down for the 130mm shot as the bokeh was making it hard to judge the size of the dragon. Just compare the relative sizes and orientation of the figures with each other and the background. For reference, the balrog is about 18 inches/46cm in front of the dragon.

Last edited by Cannikin; 04-17-2014 at 11:31 PM.
04-17-2014, 11:36 PM - 1 Like   #22
Site Supporter
ironlionzion's Avatar

Join Date: Dec 2010
Location: Dallas, TX
Posts: 409
Cannikin is correct. I find it a bit interesting that people can "hate 35mm in both formats" and "love 50mm in both formats," even though 35mm in APS-C is pretty close to the 50mm in FF. The pseudoscience in the photography world is amazing and has a clear psychological affect on many of us.
04-17-2014, 11:41 PM   #23
Veteran Member




Join Date: Apr 2011
Location: California
Photos: Gallery
Posts: 1,354
I think "compression" is a very misleading term, which does more harm than good. It less people to believe that wide and long lenses have special spacial properties, which leads to this current discussion. If you understand things in terms of perspective, lenses become less important. You don't need lenses to understand it -you see it every day with your eyes. Also, you see it in asst, when people draw using the three-Point perspective system. That system is lens-independent, but the results are mirrored by real life, in photography

camera-subject distance and subject-background distance are what determine how we see things in an image -in prey much any medium, I think. As long as three-point perspective was used to create it.

I think people being flattered by short telephoto lenses is a function of the camera being far enough from the face that we do not feel the depth of the face because the ears are not much father from the camera than the eyes are.

---------- Post added 04-17-14 at 11:43 PM ----------

QuoteOriginally posted by ironlionzion Quote
Cannikin is correct. I find it a bit interesting that people can "hate 35mm in both formats" and "love 50mm in both formats," even though 35mm in APS-C is pretty close to the 50mm in FF. The pseudoscience in the photography world is amazing and has a clear psychological affect on many of us.
If one is used to lenses with distortions and aberrations, I can see this. But that is the fault of the particular less, not the focal length, except in extreme cases.

04-17-2014, 11:59 PM   #24
Veteran Member
maltfalc's Avatar

Join Date: May 2010
Location: Winnipeg
Photos: Albums
Posts: 371
QuoteOriginally posted by mtux Quote
Place a person in front of you, take a head shot with 35mm on APSC, and one with 50mm on FF (or even APSC), check them on monitor. Which one is more flattering!?
I did this test with my wife, and showed photos to her! she's not familiar with these terms, I just asked her which one she prefer!? and the answer was obvious to me.


It is not! check these videos by Mike Brown, if you can't see it easily in your viewfinder:
Photography Tips - Focal Length Changes 3 Things - Focal Length Explained 2 - YouTube
Photography Tips: Shoot Panoramas with a Long Lens - YouTube
take your own advice.
it's all about where you're standing, not which lens you're using. even the second video you posted proves it. he moves back when he switches to the longer lens.
04-18-2014, 12:30 AM   #25
Pentaxian
Clavius's Avatar

Join Date: Feb 2011
Location: De Klundert
Photos: Gallery
Posts: 4,115
This is a topic that still gets me confused sometimes. Going to the extremes often helps. Do the exact same test as above with an ultrawide, not necessarily with a person though. And don't move the camera. Say... 15mm on APS-C and ~22 on FF. Now look at the borders and still try to claim nothing changes. This effect is present in 35mm APS-C vs 50mm FF too, only much more subtle. And this is effect is present in the center of the image as well, but also more subtle.
04-18-2014, 12:52 AM   #26
Site Supporter




Join Date: Mar 2010
Location: SW Washington
Posts: 814
QuoteOriginally posted by Clavius Quote
This is a topic that still gets me confused sometimes. Going to the extremes often helps. Do the exact same test as above with an ultrawide, not necessarily with a person though. And don't move the camera. Say... 15mm on APS-C and ~22 on FF. Now look at the borders and still try to claim nothing changes. This effect is present in 35mm APS-C vs 50mm FF too, only much more subtle. And this is effect is present in the center of the image as well, but also more subtle.
If you're talking about the visual effect that objects on the edge of the frame appear larger and stretched compared to objects in the center, this is a property of rectilinear (gnomonic) projection. It is an unavoidable consequence of trying to map a spherical field of view to a flat plane, while keeping straight lines straight. It is present in all rectilinear lenses, and is not tied to focal length but angle of view. It gets more noticeable the closer the edges get to 180 degrees. At 180 degrees it becomes infinite, which is why 180 degree rectilinear lenses are not possible no matter the format.

All rectilinear images of a given angle, regardless of format, will exhibit the same amount of stretching, barring factors such as barrel distortion which is a lens flaw. It's just the way the geometry works.
04-18-2014, 07:09 AM   #27
Pentaxian




Join Date: Jul 2009
Location: Seattle
Posts: 6,929
QuoteOriginally posted by mtux Quote
... for example portrait shots with 35mm aren't as flattering as 50mm!
So a 360mm lens on a different camera to get the approximate FOV as a 50mm on small format camera would yield even more flattering pictures?

---------- Post added 04-18-14 at 07:29 ----------

I like 35mm on FF as both a general purpose focal length and for candid people pictures. It makes you get in close for people's faces where certainly there is a forced interaction between you and the subject. A 50mm is not much different in that regard but the 35mm is wide enough on that format to get full body shots and not stand too far back. Of course everyone's milage will vary on this subject. A recent example.





04-18-2014, 07:41 AM   #28
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 7,712
QuoteOriginally posted by tuco Quote


The wide angle distortion - small head with a big shoulder here - isn't to everyone's taste.
04-18-2014, 08:33 AM   #29
Pentaxian




Join Date: Jul 2009
Location: Seattle
Posts: 6,929
QuoteOriginally posted by clackers Quote
The wide angle distortion - small head with a big shoulder here - isn't to everyone's taste.
You're right. It makes her look ugly. Perhaps something more cute with a longer focal length?

04-18-2014, 10:07 AM   #30
Site Supporter
Pewter's Avatar

Join Date: Dec 2012
Location: Toa Payoh
Photos: Gallery | Albums
Posts: 127
Original Poster
Basically your replies say I can find lens for my cropped sensor camera giving me an equivalent FOV as 24mm on a FF. I get that.

But do you get it, saying 16mm x 1.5 = 24mm does NOT mean the two are the same. Equivalence is merely convenient maths, it does not exist practically because the FF additionally has several intrinsic advantages over cropped.

If Pentax/Ricoh became wildly successful selling 35mm film cameras, whats really the reason they dont want to build a 35mm Ff sensor camera?
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, 35mm, 50mm, aps-c, body, camera, distance, equivalent, eyes, ff, format, fov, full-frame, lens, lenses, pentax, people, perspective, photography, pictures, pm, sensor, shots, subject, system, ultrawide
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
FF or just less of a crop factor? K David Pentax Full Frame 14 11-08-2013 04:28 AM
A Pentax FF idea, a unique take on the FF market... theperception2008 Pentax DSLR Discussion 20 10-03-2012 01:07 PM
Re-cycling another Pentax FF rumour/FF rumor from A German photography magazine rawr Pentax Full Frame 73 09-19-2012 01:12 PM
Just a few hopefully simple ones Seanex Troubleshooting and Beginner Help 17 02-08-2011 04:40 PM
just a simple question LeGoGubbe Photographic Technique 4 08-20-2007 11:19 AM



All times are GMT -7. The time now is 01:37 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