Home · Register · Join Upload & Sell

Moderated by: Fred Miranda
Username  

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Canon Forum | Join Upload & Sell

1      
2
       end
  

Archive 2013 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens

  
 
skibum5
Offline
• • • • • •
Upload & Sell: Off
p.2 #1 · p.2 #1 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Gonemad wrote:
Yes, thanks for pointing out that there's a correlation between the results when normalized on percentage of the delta values. That said, often times we need to look at the absolute values. For example, let's look at an example we're all (hopefully) familiar with: speeding. If someone drove a car at 1 mph and increased by 50% to 1.5 mph has the same percentage of increase if someone started at 60 mph and increased to 90 mph. However, the inherit risk and the severity of impact is different when you look at the absolute values. I guess I took the
...Show more

but the perceived isn't that absolute value



Sep 30, 2013 at 03:25 PM
Gonemad
Offline

Upload & Sell: Off
p.2 #2 · p.2 #2 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


skibum5 wrote:
I posted some shots in another thread recently, 7D puts a lot more detail than a 5D2/5D3 when distance limited. In that case I used a 300mm lens but it doesn't really matter what length.


I'm trying very hard not to get sucked into evaluating the details between the various sensor types. I just wanted to stop right where jcolwell picture illustrates: the apparent magnification. I also realize that many will call FOUL just for me suggesting that. I need to rethink a way to get my point across without dragging in the IQ. I completely understand that, at the end of the day, it's all about the final image. So, I understand IQ is everything.

I was just trying to simply point out that, mathematically, a 400mm lens seems to have a "perceived magnification" cut-off point where it wouldn't make much difference when using either a 1.3 or 1.6 crop camera. Much like an infinite value divided by 2 is still infinite. That is, either crop factor DSLR would project an image large-enough that their difference in size would be insignificant. Again, I'm not speaking of IQ but simply the projection of the image onto the sensor illustrated by jcowell without taking into consideration of the sensor size/type.



Sep 30, 2013 at 04:23 PM
rabbitmountain
Offline
• • • •
Upload & Sell: Off
p.2 #3 · p.2 #3 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Are you pointing out a point or are you asking which camera is ideal for what you want to do?

Stay good,
Ralph



Sep 30, 2013 at 04:55 PM
Gonemad
Offline

Upload & Sell: Off
p.2 #4 · p.2 #4 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


rabbitmountain wrote:
Are you pointing out a point or are you asking which camera is ideal for what you want to do?

Stay good,
Ralph


Just pointing out a mathematical "observation".



Sep 30, 2013 at 05:05 PM
rabbitmountain
Offline
• • • •
Upload & Sell: Off
p.2 #5 · p.2 #5 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Ah, that's cool. Just thought I'd ask before heading off in the wrong direction


Sep 30, 2013 at 05:39 PM
skibum5
Offline
• • • • • •
Upload & Sell: Off
p.2 #6 · p.2 #6 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Gonemad wrote:
I'm trying very hard not to get sucked into evaluating the details between the various sensor types. I just wanted to stop right where jcolwell picture illustrates: the apparent magnification. I also realize that many will call FOUL just for me suggesting that. I need to rethink a way to get my point across without dragging in the IQ. I completely understand that, at the end of the day, it's all about the final image. So, I understand IQ is everything.

I was just trying to simply point out that, mathematically, a 400mm lens seems to have a "perceived magnification" cut-off
...Show more

the thing is though that the closer lenses makes things seem the smaller the difference you need in that difference to give the same apparent feeling so it's not like a crop camera compared to FF matters a ton at 21mm and almost nothing at 800mm so i don't believe the premise



Sep 30, 2013 at 07:28 PM
Pixel Perfect
Offline
• • • • • • •
Upload & Sell: On
p.2 #7 · p.2 #7 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


jcolwell wrote:
There is no "magnification" at the sensor. The image on the sensor is the same size for a 1.6x CF camera as for a full frame camera. The magnification occurs when you enlarge the image to print it or show it on a monitor.


I'm going to play devil's advocate here. There is no enlarging going on in the digital world. If I have two sensors with the same resolution, but different sizes, they both produce the same m x n sized image as you say, and I send them to the printer, nothing's different, no enlargement going on here either. Both will produce the same size print at the same dpi. Printer just prints what you give it. If I want enlargement I have choose to print larger, so if I print FF file 1.6x larger on a side, and take some scissors and trim it down by a factor of 1.6x I have a print that looks identical to the smaller print from the crop camera. Now we have effective magnification.

It's not like the old analogue days of film, where you had to scan the negative first and indeed you did have to enlarge the image more for the smaller format.




Sep 30, 2013 at 08:41 PM
Gonemad
Offline

Upload & Sell: Off
p.2 #8 · p.2 #8 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Pixel Perfect wrote:
I'm going to play devil's advocate here. There is no enlarging going on in the digital world. If I have two sensors with the same resolution, but different sizes, they both produce the same m x n sized image as you say, and I send them to the printer, nothing's different, no enlargement going on here either. Both will produce the same size print at the same dpi. Printer just prints what you give it. If I want enlargement I have choose to print larger, so if I print FF file 1.6x larger on a side, and take some
...Show more

Perfectly good example. So, let's use your example of two sensors with the same resolution but different sizes. If you agree with jcolwell's picture (see page 1), then you should also agree the bug formed at the focal plane would "fill" more on the smaller sensor than the larger sensor. If you say printer just prints, then if I were to send the image file from the larger sensor to the printer the bug will appear smaller on print as compared to the print from the smaller sensor - same paper and same dpi. In which case, whatever this "crop magnification" is called, it's not imaginary. Is it not? I'm sorry if I fail to see your point...



Oct 01, 2013 at 12:24 AM
Pixel Perfect
Offline
• • • • • • •
Upload & Sell: On
p.2 #9 · p.2 #9 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


I'm not arguing against the effective magnification, yes we have effective magnification as per Jim's post and as I demonstrated above. But this is just a function of the printer not the sensor as Jim said. I'm arguing against the notion it's the same as with analogue film, where we were physically enlarging the negative to transfer to photo paper and the format size was important. We needed to enlarge the smaller format negative much more to make the same sized prints. Now we just have a digital file.

No real point other than this.



Oct 01, 2013 at 01:03 AM
Larate
Offline
• •
Upload & Sell: Off
p.2 #10 · p.2 #10 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Pixel Perfect wrote:
I'm going to play devil's advocate here. There is no enlarging going on in the digital world. If I have two sensors with the same resolution, but different sizes, they both produce the same m x n sized image as you say, and I send them to the printer, nothing's different, no enlargement going on here either. Both will produce the same size print at the same dpi. Printer just prints what you give it. If I want enlargement I have choose to print larger, so if I print FF file 1.6x larger on a side, and take some
...Show more

That's what I have to explain every time. People make the confusion between the sensor size and the digitally made photo, which is a discretization of the world they see through the viewfinder.
I was thinking how to explain it one more time, but a bit more challenging this time : in English with French proposals from my tablet. Thanks to have "eased" my life !



Oct 01, 2013 at 02:07 AM
Larate
Offline
• •
Upload & Sell: Off
p.2 #11 · p.2 #11 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Gonemad wrote:
Perfectly good example. So, let's use your example of two sensors with the same resolution but different sizes. If you agree with jcolwell's picture (see page 1), then you should also agree the bug formed at the focal plane would "fill" more on the smaller sensor than the larger sensor. If you say printer just prints, then if I were to send the image file from the larger sensor to the printer the bug will appear smaller on print as compared to the print from the smaller sensor - same paper and same dpi. In which case, whatever this "crop
...Show more

You've made several confusions. I'll try to explain but please be forgiving as English is not my native language (and the f...ing keyboard of my tablet is too small !).

If you want to compare photos shot with sensors of different sizes, you have to keep the other parameters "independent". It means the same FoV, the same DoF and the same speed. Let's name the results "equivalent photos".

Whatever is your sensor, it actually digitalizes a portion of reality into a sequence of points (named pixels). This sequence is actually an array whose size is pre-determined by the capabilities of the sensor (and some configuration too). In the end, you've got a picture of X x Y points. These are the points that are sent to the printer, or the monitor. There's no more reference to their origin (sensor A or B, except in the metadata).

So if you take an equivalent picture of a bug with a FF camera and an APS-C camera both having the same resolution, at the end you've got the same picture. No one will be enlarged more. And the bug will have the same size.

Regarding how the magnification is evolving with lenses, there are two factors involved. First is the apparent magnification in the viewfinder : how bigger one sees the subject when changing the focal. The second factor is how many pixels we can put to the subject (the part of the image we want to print). That's another story (but it's interesting too).

Pwew, at least I've reached the end. Dunno which one. Maybe the dark side ?!




Oct 01, 2013 at 03:17 AM
Gonemad
Offline

Upload & Sell: Off
p.2 #12 · p.2 #12 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Pixel Perfect wrote:
I'm not arguing against the effective magnification, yes we have effective magnification as per Jim's post and as I demonstrated above. But this is just a function of the printer not the sensor as Jim said. I'm arguing against the notion it's the same as with analogue film, where we were physically enlarging the negative to transfer to photo paper and the format size was important. We needed to enlarge the smaller format negative much more to make the same sized prints. Now we just have a digital file.

No real point other than this.


Thanks for re-iterating your point. For some reason, I thought you didn't agree with the effective magnification. Now I see we actually agree more than disagree!



Oct 01, 2013 at 11:28 AM
Gonemad
Offline

Upload & Sell: Off
p.2 #13 · p.2 #13 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Larate wrote:
You've made several confusions. I'll try to explain but please be forgiving as English is not my native language (and the f...ing keyboard of my tablet is too small !).

If you want to compare photos shot with sensors of different sizes, you have to keep the other parameters "independent". It means the same FoV, the same DoF and the same speed. Let's name the results "equivalent photos".

Whatever is your sensor, it actually digitalizes a portion of reality into a sequence of points (named pixels). This sequence is actually an array whose size is pre-determined by the capabilities of
...Show more
Larate, no need to apologize for your English - perfectly fine. Thanks for sharing your angle.



Oct 01, 2013 at 11:29 AM
skibum5
Offline
• • • • • •
Upload & Sell: Off
p.2 #14 · p.2 #14 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


Gonemad wrote:
Perfectly good example. So, let's use your example of two sensors with the same resolution but different sizes. If you agree with jcolwell's picture (see page 1), then you should also agree the bug formed at the focal plane would "fill" more on the smaller sensor than the larger sensor. If you say printer just prints, then if I were to send the image file from the larger sensor to the printer the bug will appear smaller on print as compared to the print from the smaller sensor - same paper and same dpi. In which case, whatever this "crop
...Show more

yes, but only because you also said "....with the same resolution" (assuming by that you mean the same total MP count and not the same photosite density)



Oct 01, 2013 at 02:13 PM
Gonemad
Offline

Upload & Sell: Off
p.2 #15 · p.2 #15 · No significant advantage to use 1.6x vs 1.3x crop DSLR with super-tele lens


skibum5 wrote:
yes, but only because you also said "....with the same resolution" (assuming by that you mean the same total MP count and not the same photosite density)


Yes. Phew, now we're getting somewhere... :-)



Oct 01, 2013 at 05:52 PM
1      
2
       end




FM Forums | Canon Forum | Join Upload & Sell

1      
2
       end
    
 

You are not logged in. Login or Register

Username       Or Reset password



This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.