Misconception: Using an FX lens on a DX camera "extends the reach" of the lens

[MasterOfGoingFaster]

Using a lens designed for an FX size sensor on a camera with a DX
size sensor DOES NOT "extend the reach" or change the effective focal
length of the lens.

Please define the terms "effective focal length" and "extend the reach". By some definitions, your statement is incorrect, so I'd like to hear your definitions.

--
Ken Elliott
Equipment in profile.

 

[brightcolours]

Using a lens designed for an FX size sensor on a camera with a DX
size sensor DOES NOT "extend the reach" or change the effective focal
length of the lens.

Please define the terms "effective focal length" and "extend the
reach". By some definitions, your statement is incorrect, so I'd
like to hear your definitions.

--
Ken Elliott
Equipment in profile.

MISCONCEIVE resolution with reach. They are obsessed with the notion that somehow pixel density gives more reach. They do not get that pixel density ONLY gives more resolution, that tele reach is about the IMAGE, not the resolution.

Very tiresome, very silly, and very wrong.

 

[Josh69]

I think everyone understands this and they understood it around 2003 or so.

I bet you could find the same thread several times a year, since the first DX camera came out.

 

[Saint Yves]

but you are at a distance from your subject, you use the light coming from the subject so "reach" means very little really.

--
Yves

 

[brightcolours]

but you are at a distance from your subject, you use the light
coming from the subject so "reach" means very little really.

--
Yves

Then a 24mm lens and a 800mm lens on the same camera give you the same "reach" according to your mangling of the term reach.

 

[Iliah Borg]

They are obsessed with the notion
that somehow pixel density gives more reach.

You have 2 films, one with small grain, and one with large. Which film allows you to crop tighter? For which film you will need a longer lens to get crops of equal apparent resolution?

--
http://www.libraw.org/

 

[Austin Li]

I think everyone understands this and they understood it around 2003
or so.

I bet you could find the same thread several times a year, since the
first DX camera came out.

You are right. But sadly, there are still guys who seem don't get it. They still believe DX format has longer reach than full frame format.
--
Austin

Photography is one of the ways to get myself relaxed from occupation stress.

 

[GoldRingNikkor]

MISCONCEIVE resolution with reach. They are obsessed with the notion
that somehow pixel density gives more reach. They do not get that
pixel density ONLY gives more resolution, that tele reach is about
the IMAGE, not the resolution.

I understand the words, but I don't get your point. "Tele reach is about the image, not the resolution" - yeah, right, and my D300 image (read: image) shows more detail than my D700 image (again: image) if I use the same lens (read: same focal length) because the 12 MP DX sensor has more pixel density than the 12 MP FX sensor. So, I don't get why IMAGE and RESOLUTION (notice the CAPITALS) are supposed to be unrelated...

 

[Austin Li]

MISCONCEIVE resolution with reach. They are obsessed with the notion
that somehow pixel density gives more reach. They do not get that
pixel density ONLY gives more resolution, that tele reach is about
the IMAGE, not the resolution.

Very tiresome, very silly, and very wrong.

OK, would you please define the term "reach"? My understanding of "reach" is the ability of resolving the fine detail of a distant object, either by longer lens or the camera sensor. Please correct me, thank you!
--
Austin

Photography is one of the ways to get myself relaxed from occupation stress.

 

[brightcolours]

They are obsessed with the notion
that somehow pixel density gives more reach.

You have 2 films, one with small grain, and one with large. Which
film allows you to crop tighter? For which film you will need a
longer lens to get crops of equal apparent resolution?

--
http://www.libraw.org/

Who is talking about cropping?
Why do you want to make it about cropping?

A photo is a photo, regardless of its resolution. Stuff your cropping where it belongs, and just look at the results out of the camera.

Silly stuff, this wave of people who want to argue that a smaller sensor does not give more tele reach. Demented, actually.

 

[brightcolours]

MISCONCEIVE resolution with reach. They are obsessed with the notion
that somehow pixel density gives more reach. They do not get that
pixel density ONLY gives more resolution, that tele reach is about
the IMAGE, not the resolution.

I understand the words, but I don't get your point. "Tele reach is
about the image, not the resolution" - yeah, right, and my D300 image
(read: image) shows more detail than my D700 image (again: image) if
I use the same lens (read: same focal length) because the 12 MP DX
sensor has more pixel density than the 12 MP FX sensor. So, I don't
get why IMAGE and RESOLUTION (notice the CAPITALS) are supposed to be
unrelated...

Your D300 image does NOT show more detail at all. Where do you get that notion from? If you make the same photo with each camera, you get the same detail. But you will have to use a different focal length.

So, NOT more detail with a D300. Regardeless of whether it has more pixel density or not.
The only difference will be the more shallow depth of field with a D700.

 

[Jeff Kohn]

... is that it assumes that we care about optical magnification. With the exception of a few anal know-it-all types, we don't.

For real-world photography, what we care about is how many pixels we can get on a given field of view from a given location. By that criteria, yes the DX cameras give you more "reach", at least until FX cameras with equivalent pixel densities become common place.

Bottom line, a birder who's already using their longest glass will get more image data on their subject with a D300 than a D700. To argue otherwise just because the focal length and optical magnification are the same seems stupid and pointless to me.

--
Jeff Kohn
Houston, TX
http://www.pbase.com/jkohn
http://jeffk-photo.typepad.com

 

[Iliah Borg]

They are obsessed with the notion
that somehow pixel density gives more reach.

You have 2 films, one with small grain, and one with large. Which
film allows you to crop tighter? For which film you will need a
longer lens to get crops of equal apparent resolution?

Who is talking about cropping?

Mostly, those who understand practical aspects of photography.

A photo is a photo, regardless of its resolution.

LOL

Silly stuff, this wave of people who want to argue that a smaller
sensor does not give more tele reach. Demented, actually.

I'm afraid you do not understand.

--
http://www.libraw.org/

 

[brightcolours]

MISCONCEIVE resolution with reach. They are obsessed with the notion
that somehow pixel density gives more reach. They do not get that
pixel density ONLY gives more resolution, that tele reach is about
the IMAGE, not the resolution.

Very tiresome, very silly, and very wrong.

OK, would you please define the term "reach"? My understanding of
"reach" is the ability of resolving the fine detail of a distant
object, either by longer lens or the camera sensor. Please correct
me, thank you!
--
Austin

Photography is one of the ways to get myself relaxed from occupation
stress.

Your understanding is hampered.

A Nikon D70 with a 300mm f4 lens gives EXACTLY the same photo results as a Nikon D90 with 300mm f4 lens.
The same composition, same depth of field, same reach towards the subject.

REACH, to get closer from where you are standing, onto the image you get from the camera. Nothing to do with the resolution of the photo.

And yet the D90 has 12.x MP and the D70 6.1 mp.
Megapixels have NOTHING to do with tele "reach".

And it all has nothing to do with the ability to crop more with more megapixels either.

When I make a photo with my 12.2mp camera, with a 500mm lens, And I downscale the photo to under 0.5mp to post on a forum like this, it STILL is a photo with EXACTLY the same characteristics as the original 12.2MP photo.

In your warped way of discussing this, it would mean that all of a sudden, by downsizing my photo and reducing the resolution a lot, it would become, lets say a 24mm photo.

UHMMM right. That makes sense... NOT.

Or if I make a photo with my 12.2 mp camera, with a 200mm lens. And I print it out at lets say 50x75mm. And I hang it on a wall.

In your warped idea, if I would stand close to the image, it would be a 200mm image. Yet when I walk away from it, and I can not see all detail anymore, and the image gets smaller in my field of view, the photo starts to become a 50mm photo.

Uhmm.. right. I think not. Resolution has NOTHING to do here in how to look at focal lengths. Nothing at all.

 

[brightcolours]

... is that it assumes that we care about optical magnification. With
the exception of a few anal know-it-all types, we don't.

I guess there are a few anal know-it-all types who shoot whatever and only care about resolution to be able to cop a lot.
Real photographers frame a shot, and could care less about resolution, really.

They care about what they see through the lens. That is where tele REACH comes in.
Nothing to do with resolution.

For real-world photography, what we care about is how many pixels we
can get on a given field of view from a given location. By that
criteria, yes the DX cameras give you more "reach", at least until FX
cameras with equivalent pixel densities become common place.

Bottom line, a birder who's already using their longest glass will
get more image data on their subject with a D300 than a D700. To
argue otherwise just because the focal length and optical
magnification are the same seems stupid and pointless to me.

Bottom line is that a birder almost never is a photographer, but the ornithological equivalent of a train spotter.

--
Jeff Kohn
Houston, TX
http://www.pbase.com/jkohn
http://jeffk-photo.typepad.com

 

[brightcolours]

They are obsessed with the notion
that somehow pixel density gives more reach.

You have 2 films, one with small grain, and one with large. Which
film allows you to crop tighter? For which film you will need a
longer lens to get crops of equal apparent resolution?

Who is talking about cropping?

Mostly, those who understand practical aspects of photography.

A photo is a photo, regardless of its resolution.

LOL

Silly stuff, this wave of people who want to argue that a smaller
sensor does not give more tele reach. Demented, actually.

I'm afraid you do not understand.

--
http://www.libraw.org/

If you have 2 films, one with big grain, and one with smaller grain, does that influence the focal length of your lens? According to you, reasoning the other way around, it does. Bravo.

 

[Austin Li]

A Nikon D70 with a 300mm f4 lens gives EXACTLY the same photo results
as a Nikon D90 with 300mm f4 lens.
The same composition, same depth of field, same reach towards the
subject.

So you are saying they have the same reach. I would agree that the reach of the lens is the same apparently, but the D90 offers more reach. Because if you print large enough, which one will give more detail?

Calm down, buddy, we are discussing and learning, not really arguing or fighting.

 

[Iliah Borg]

If you have 2 films, one with big grain, and one with smaller grain,
does that influence the focal length of your lens?

It does affect my choice of the lens. As I said, you do not understand.

--
http://www.libraw.org/

 

[michaeladawson]

Brightcolours, you have just revealed your true colors. I am in general agreement with you on using the correct lens for the job. I'm not going to use a 100mm lens and crop when I can use a 150mm and frame my subject the way I want. But then, I rarely ever need a focal length longer than 200mm.

But I think you've lost steam with your argument when you start determining who you think is worthy of being called a photographer and who is not. You know, at some point the money runs out. Some people have to make due with a 300mm because a 400 or 500mm is prohibitively expensive. DX format allows one to capture the same amount of pixels and the same field of view with 33% less focal length as FX (assuming equal MP cameras such as a D3 vs. D300). If the term "reach" bothers you so much fine, don't use it.

Labeling birders as train spotters and not worthy of being called photographers is just plain silly and undermines your argument.

... is that it assumes that we care about optical magnification. With
the exception of a few anal know-it-all types, we don't.

I guess there are a few anal know-it-all types who shoot whatever and
only care about resolution to be able to cop a lot.
Real photographers frame a shot, and could care less about
resolution, really.
They care about what they see through the lens. That is where tele
REACH comes in.
Nothing to do with resolution.

For real-world photography, what we care about is how many pixels we
can get on a given field of view from a given location. By that
criteria, yes the DX cameras give you more "reach", at least until FX
cameras with equivalent pixel densities become common place.

Bottom line, a birder who's already using their longest glass will
get more image data on their subject with a D300 than a D700. To
argue otherwise just because the focal length and optical
magnification are the same seems stupid and pointless to me.

Bottom line is that a birder almost never is a photographer, but the
ornithological equivalent of a train spotter.

--
Jeff Kohn
Houston, TX
http://www.pbase.com/jkohn
http://jeffk-photo.typepad.com

--
Mike Dawson

 

[brightcolours]

If you have 2 films, one with big grain, and one with smaller grain,
does that influence the focal length of your lens?

It does affect my choice of the lens. As I said, you do not understand.

--
http://www.libraw.org/

Ah... YOUR choice of lens.

And you may understand that SERIOUS photographers only care about the composition, framing and what the chosen focal length does to their image.

And they really do not care about resolution the way you seem to do, and they will not talk such nonsense about tele "reach".

That is the difference... you not being a photographer but a detail capturer.