Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-24-2019, 03:52 PM   #271
GUB
Loyal Site Supporter
Loyal Site Supporter
GUB's Avatar

Join Date: Aug 2012
Location: Wanganui
Photos: Gallery | Albums
Posts: 4,126
QuoteOriginally posted by PDL Quote
Exposure is Shutter speed, ISO & F:stop ... FOV is not a parameter in the equation. Also note: there is no discussion of "total light", that is a made up term.

"In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance in a specified region."
Hopefully you realise that Photobill was replying to ISF and "The term " EQUIVALENT EXPOSURE" refers to exposure (SS, ISO & F:stop) + FOV? " was a question not a position by Photobill

08-24-2019, 04:01 PM   #272
PDL
Pentaxian




Join Date: Oct 2006
Location: PNW USA
Photos: Gallery
Posts: 2,014
QuoteOriginally posted by pschlute Quote
The discussion was about physical size not pixel dimensions.

We really would be in trouble if a digital image did not know how many pixels it contained.
So you failed to read the following?

However, there is no sensor size in mm provided in the EXIF.

Read more at: lens light-gathering abilities - Page 18 - PentaxForums.com

---------- Post added 08-24-19 at 04:03 PM ----------

QuoteOriginally posted by GUB Quote
Hopefully you realise that Photobill was replying to ISF and "The term " EQUIVALENT EXPOSURE" refers to exposure (SS, ISO & F:stop) + FOV? " was a question not a position by Photobill
And I answered the question. FOV has no place in exposure nor does "total light".
08-24-2019, 04:15 PM   #273
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 4,610
QuoteOriginally posted by PDL Quote
So you failed to read the following?

However, there is no sensor size in mm provided in the EXIF.

Read more at: lens light-gathering abilities - Page 18 - PentaxForums.com
I am not really sure of your point here.

You quoted me replying to a claim (post 202) that a digital image has a physical size 16x24mm the case in point. I made the point that a digital image has no physical size.

You seem to be trying to make the same point back to me
08-24-2019, 08:00 PM - 1 Like   #274
Pentaxian
swanlefitte's Avatar

Join Date: May 2015
Location: New Orleans
Photos: Gallery
Posts: 3,342
Y=2x plotted on a graph in terms of enlargement is meaningless. If my graph paper has bigger squares than the person's who plotted the original data had, doesn't make it a different size. Sure you can look at both and say it's bigger in one manifestation but y=2x is just a formula. Same with the data in a raw file.

08-24-2019, 10:32 PM   #275
Pentaxian




Join Date: Dec 2011
Posts: 2,827
The claim the earth was round is a virtual concept only. In fact it is flat as we can see.
08-24-2019, 11:42 PM   #276
Moderator
Site Supporter
Loyal Site Supporter
MarkJerling's Avatar

Join Date: May 2012
Location: Wairarapa, New Zealand
Photos: Gallery | Albums
Posts: 15,235
QuoteOriginally posted by beholder3 Quote
With my previous comment you quoted I was just pointing out that a FF lens on aAPSC body smacks a lot of captured photons against the backside innards of the mirror box instead of on the sensor when not using a wide angle converter. All this previously captured light is lost.
I really feel you should expand on this theory more.
08-25-2019, 12:10 AM - 5 Likes   #277
Pentaxian
Dartmoor Dave's Avatar

Join Date: Aug 2012
Location: Dartmoor, UK
Photos: Gallery | Albums
Posts: 2,578
This thread:


08-25-2019, 07:12 AM   #278
Pentaxian
StephenHampshire's Avatar

Join Date: Oct 2009
Location: Winchester
Photos: Gallery | Albums
Posts: 2,314
QuoteOriginally posted by Dartmoor Dave Quote
I wish there was a multiple like button! Small......far away

08-25-2019, 07:16 AM - 1 Like   #279
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 16,428
QuoteOriginally posted by beholder3 Quote
The claim the earth was round is a virtual concept only. In fact it is flat as we can see.
If you consider how proofs are done in calculus, you will find that most differential equation solutions are based upon straight line solutions as curves are eventually considered in the limit as distance approaches 0 as straight lines. Therefore I think you could prove that the flat earth is just the earth as seen as the viewing distance approaches zero
08-25-2019, 01:10 PM - 1 Like   #280
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 2,102
Earth is round, everyone knows that. Just like a Pizza.
08-28-2019, 02:25 AM - 1 Like   #281
dbs
Pentaxian




Join Date: Jun 2010
Location: Clare Valley S A
Photos: Albums
Posts: 5,761
The Earth is less flat the higher you get................pretzels ....anyone....?


Dave
08-28-2019, 09:33 AM   #282
Pentaxian
Fogel70's Avatar

Join Date: Sep 2009
Location: Stockholm, Sweden
Photos: Albums
Posts: 2,250
That is just because the higher you get on the good stuff, the more distorted your vision gets.
08-28-2019, 03:51 PM - 1 Like   #283
GUB
Loyal Site Supporter
Loyal Site Supporter
GUB's Avatar

Join Date: Aug 2012
Location: Wanganui
Photos: Gallery | Albums
Posts: 4,126
Yep and when you get up really high you can see that, because the earth is larger than the moon, it is brighter. All about total light you know.
08-28-2019, 04:58 PM   #284
dbs
Pentaxian




Join Date: Jun 2010
Location: Clare Valley S A
Photos: Albums
Posts: 5,761
But moonshine makes it distorted but not always high.

Light on

Dave
08-29-2019, 05:12 AM - 1 Like   #285
Senior Member




Join Date: Feb 2018
Location: Southern Oregon
Posts: 228
Original Poster
After a few shots of moonshine and a handful of pretzels, Iíve been wondering ??? Is the moon small or far away?????
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!
50mm, amount, aps-c, bokeh, camera, distance, energy, exposure, ff, image, iris, iso, jpg, k-mount, lens, light, metal, paint, pentax lens, pixel, print, sensor, shutter, size, slr lens, unit, water
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Thought FF (k1) would give me. Significant increase in light gathering vs k70 Mazzoman Pentax Full Frame 31 12-10-2017 12:57 AM
FF vs APS-C light gathering / noise CypherOz General Photography 21 06-13-2014 10:25 AM
60-250/50-135 macro abilities jenst Pentax SLR Lens Discussion 3 05-13-2014 06:22 PM
A Realization on my Abilities interested_observer Pentax SLR Lens Discussion 19 04-22-2014 09:04 PM
Is there unit for light gathering properties of a lens? Reportage Pentax SLR Lens Discussion 9 03-12-2012 07:37 AM



All times are GMT -7. The time now is 09:39 AM. | 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