Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-30-2015, 06:48 PM   #1
Pentaxian




Join Date: May 2012
Posts: 2,962
Lens Rendering Discussion

First off-- I have to admit--I avoid the full frame section like the plague. I don't think much good comes out of all the redundant discussion on the same topics over and over and over again. That said I never thought I would be posting anything in here, but here goes nothing

My questions and/or topic of discussion is NOT about equivalence although I will reference angle of view to some degree.

What I am curious about is for those on the forum who are in the know to talk about a specific aspect of angle of view as it pertains to lenses.

Here is what I am asking/thinking of. Lets say I took a picture of a person standing in front of a scene with a DA21mm lens on my K3. Now lets say I never move my tripod, model, scene, or anything and I put a FF Pentax camera on the tripod with a FA 31mm lens. I am interested in how the scene would look, and the differences therein.

Would the person appear bigger or smaller in one or the other? Would there be any noticeable differences? I am not asking about sharpness, bokeh, or anything else. I am asking about a 'perspective' question....Just to keep it simple lets say BOTH lenses were set on f8 for the mythical test.

For the record the 21mm has a horizontal FOV of 59 degrees and the 31mm would have an angle of 60 degrees on each respective camera. The field of view, while not exactly identical, is still pretty close.

Bonus points if you can show an uncropped side by side comparison of the test I mentioned.

Again it's not about sharpness. It's not about rendering. It's also not about about depth of field, or resolution or any of that. It's about how the different focal lengths of the lenses will record the same scene.

Discuss.

---------- Post added 07-30-15 at 08:56 PM ----------

As a reference here is a Pentax Forum home page article.

A Guide to Perspective Distortion Review - Introduction | PentaxForums.com Reviews

---------- Post added 07-30-15 at 09:11 PM ----------

My theory is that the 31mm lens on the FF camera will bring my model out much more prominently in the same scene than the 21mm will. Not because of any sensor magic, but because it is a longer focal length.

It will make a much more prominent subject (ie the model).

I am not 100% sure on this, but what say you?


Last edited by alamo5000; 07-30-2015 at 07:00 PM.
07-30-2015, 07:24 PM   #2
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,178
Grabbing the popcorn.
07-30-2015, 07:36 PM   #3
Pentaxian




Join Date: May 2012
Posts: 2,962
Original Poster
QuoteOriginally posted by UncleVanya Quote
Grabbing the popcorn.
LOL!!!

I thought I would put this one in the lens section because it's much more of a lens question than anything.

I am just curious as to what others might have to say about my theory.

And the thing is... if we can find someone who has a digital body and a film body with both of the lenses mentioned... we can prove it or disprove it.

I don't know the answer... but I am seeing what people have to say.
07-30-2015, 07:50 PM   #4
Veteran Member




Join Date: Oct 2011
Posts: 821
I'm not sure but it's the background size in relation to the subject that might differ..

07-30-2015, 08:07 PM   #5
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jun 2009
Location: Tumbleweed, Arizona
Photos: Gallery | Albums
Posts: 5,699
QuoteOriginally posted by UncleVanya Quote
Grabbing the popcorn.
You forgot the butter!

07-30-2015, 08:13 PM   #6
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,178
Similar studies have been done by canikon users.

Here is one: Canon Lenses on Full Frame vs Crop | Photographers' Lounge
07-30-2015, 08:16 PM   #7
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
QuoteOriginally posted by UncleVanya Quote
Grabbing the popcorn.
Sorry I got there first. You can sit in the comfy chair though.


The answer, of course is to simply go to the film section of this site where there are plenty of photos taken at multiple focal lengths of some very typical subjects. (Translation: There truly is nothing to discuss.)

BTW...when is a thread that includes the words "lens rendering discussion" not about rendering?

QuoteOriginally posted by alamo5000 Quote
It's not about rendering.

Steve

07-30-2015, 08:18 PM   #8
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,178
QuoteOriginally posted by interested_observer Quote
You forgot the butter!

Whoops. I'd like some peanut m&m's also.
07-30-2015, 08:20 PM   #9
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
QuoteOriginally posted by alamo5000 Quote
My theory is that the 31mm lens on the FF camera will bring my model out much more prominently in the same scene than the 21mm will. Not because of any sensor magic, but because it is a longer focal length.

It will make a much more prominent subject (ie the model).

I am not 100% sure on this, but what say you?

Nope


Steve
07-30-2015, 08:21 PM   #10
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
FA 31 - Search Results - PentaxForums.com


Steve
07-30-2015, 08:27 PM   #11
Pentaxian




Join Date: May 2012
Posts: 2,962
Original Poster
QuoteOriginally posted by stevebrot Quote
BTW...when is a thread that includes the words "lens rendering discussion" not about rendering?
Because I didn't know the correct words to use to express what I was trying to say.

---------- Post added 07-30-15 at 11:01 PM ----------

QuoteOriginally posted by stevebrot Quote
Nope
I am very open to the idea that I am/could be/might be/ or am wrong

I don't know the answer. That's what it boils down to.
07-30-2015, 09:05 PM   #12
Veteran Member
RAART's Avatar

Join Date: Apr 2013
Location: Oakville, ON
Photos: Gallery
Posts: 1,095
I think that depth of field is different as well as background compression, otherwise almost identical... If I remember correctly when I had Nikon FF and APS-C bodies. But sure thing that I always went for FF in regards of ISO noise difference.
07-30-2015, 09:06 PM   #13
Moderator
Site Supporter
Loyal Site Supporter
Sandy Hancock's Avatar

Join Date: Feb 2012
Location: Adelaide Hills, South Australia
Photos: Gallery | Albums
Posts: 11,254
I promise you, with my hand on my heart, this will be just about the first things I do when I take delivery of my 36x24 Pentax.
Be patient

---------- Post added 31-07-15 at 01:45 PM ----------

QuoteOriginally posted by UncleVanya Quote
In essence then, if you use an "equivalent" f-stop, bugger all difference: as expected. The FA31 on full frame will obviously give far greater depth of field control - at the shallow end at least.

Last edited by Sandy Hancock; 07-30-2015 at 09:15 PM.
07-30-2015, 09:23 PM   #14
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,178
QuoteOriginally posted by Sandy Hancock Quote
I promise you, with my hand on my heart, this will be just about the first things I do when I take delivery of my 36x24 Pentax.
Be patient

---------- Post added 31-07-15 at 01:45 PM ----------


In essence then, if you use an "equivalent" f-stop, bugger all difference: as expected. The FA31 on full frame will obviously give far greater depth of field control - at the shallow end at least.
Yup. I saw some other image comparisons but few gave the same perspective side by side. I'm pretty sure we can find these but this was the most promising one I found ready made.
07-30-2015, 09:40 PM   #15
Veteran Member




Join Date: Jan 2012
Location: Slovenia
Photos: Gallery
Posts: 2,182
Can I add my "8mm fisheye on a Q10 vs 43ltd on FF" question to the mix?
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, 31mm, angle, bokeh, camera, degrees, discussion, disks, field, frame, full-frame, lens, lenses, model, pentax, record, scene, sharpness, test, thanks, view, words
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lens color rendering and white balance biz-engineer Photographic Technique 10 03-16-2015 02:18 PM
Rendering vs sharpness ChristianRock Pentax SLR Lens Discussion 20 05-07-2014 01:28 AM
No more lens clubs in the discussion thread Igilligan Site Suggestions and Help 75 01-12-2010 03:44 PM
Error with thread in lens discussion clawhammer Site Suggestions and Help 4 09-18-2007 09:47 PM
Make the Lens Discussion forum open to all... carpents Site Suggestions and Help 9 09-09-2006 05:28 AM



All times are GMT -7. The time now is 05:41 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