HTFC Forums

H.T.F.C.

How To Fix Computers





Go Back   HTFC Forums > Hardware Newsgroups > Digital Photo

Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 04-18-2007, 03:59 PM
Oscar
 
Posts: n/a
Default 35mm SLR lenses on digital

Hi,

I've owned a Nikon F401s for many years and always enjoyed using it,
but with the onset of digital cameras my SLR was assigned to the
cupboard in favour of a couple of super zoom digital cameras. Anyway
I now feel the need to change away from these back to a proper SLR and
have been looking at the Nikon D40, D40x and D80.

I already own three lenses form my SLR days and I know if I brought
either of the D40 models these lenses will not auto focus.

What I don't understand is the way the lenses are now described

ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
film days, understand.

All new lenses now seem to be marketed this way, but what if you
already have lenses which are from the 35mm film days. Does it mean
the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
somebody please help.

Please don't turn this message in to a debate over which camera is the
best as there are loads of these around, I know the pitfalls of the
D40 models over the D80.

Thanks

Oscar

Reply With Quote
Sponsored Links
Fix your Windows Problems - FAST.
FREE Safe Scan Registry Check. Locate & Fix Errors in Minutes!
  #2  
Old 04-18-2007, 04:05 PM
Daniel Silevitch
 
Posts: n/a
Default Re: 35mm SLR lenses on digital

On 18 Apr 2007 07:59:14 -0700, Oscar <a_h_1969@hotmail.com> wrote:
> Hi,
>
> I've owned a Nikon F401s for many years and always enjoyed using it,
> but with the onset of digital cameras my SLR was assigned to the
> cupboard in favour of a couple of super zoom digital cameras. Anyway
> I now feel the need to change away from these back to a proper SLR and
> have been looking at the Nikon D40, D40x and D80.
>
> I already own three lenses form my SLR days and I know if I brought
> either of the D40 models these lenses will not auto focus.
>
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.


Multiplied by 1.5, so 52.5-105mm.

-dms
Reply With Quote
  #3  
Old 04-18-2007, 04:09 PM
Bob Williams
 
Posts: n/a
Default Re: 35mm SLR lenses on digital



Oscar wrote:
> Hi,
>
> I've owned a Nikon F401s for many years and always enjoyed using it,
> but with the onset of digital cameras my SLR was assigned to the
> cupboard in favour of a couple of super zoom digital cameras. Anyway
> I now feel the need to change away from these back to a proper SLR and
> have been looking at the Nikon D40, D40x and D80.
>
> I already own three lenses form my SLR days and I know if I brought
> either of the D40 models these lenses will not auto focus.
>
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.
>
> Please don't turn this message in to a debate over which camera is the
> best as there are loads of these around, I know the pitfalls of the
> D40 models over the D80.
>
> Thanks
>
> Oscar
>

Your old Nikon Lenses on a new Nikon D40 etc, will act as if the focal
length is (Old F.L. X Magnification Factor). The M.F. for the D40 is
1.5, so your old 35-70will behave like a 52.5-105 on the D40
Bob Williams

Reply With Quote
  #4  
Old 04-18-2007, 04:16 PM
Jürgen Exner
 
Posts: n/a
Default Re: 35mm SLR lenses on digital

Oscar wrote:
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.


For me the easiest way is to remember that what is stamped on the barrel is
standardized for 35mm film. That means, if you are using that D80 kit lens
(18-70mm) on a 35mm film camera than you will get an 18-70mm zoom lens.

Now, compared to 35mm film the D80 has a conversion factor of 1.5. That
means that because of the smaller sensor compared to film this lens when
used on a D80 has a zoom range of 18x1.5-70x1.5 which equals 27-105mm.
Same with your old lenses. 35-70 on 35mm film times 1.5 on the D80 equals
52-105mm.

Unfortunately this conversion is necessary because different cameras have
different sensors dimensions and therefore different conversion factors,
e.g. if you were to use this D80 kit lens on some other camera you probably
end up with slightly different numbers. The one thing to remember is that
what is stamped on the lens is always for 35mm film.

jue


Reply With Quote
  #5  
Old 04-18-2007, 04:56 PM
Scott Schuckert
 
Posts: n/a
Default Re: 35mm SLR lenses on digital

In article <JDqVh.5522$F32.1633@trndny02>, Jürgen Exner
<jurgenex@hotmail.com> wrote:

> Unfortunately this conversion is necessary because different cameras have
> different sensors dimensions and therefore different conversion factors,
> e.g. if you were to use this D80 kit lens on some other camera you probably
> end up with slightly different numbers. The one thing to remember is that
> what is stamped on the lens is always for 35mm film.


Or, more accurately, what is stamped on the lens is always WHAT THE
FOCAL LENGTH ACTUALLY IS.

The field of view that focal length gives (compared to 35 mm) is what
the magnification factor tells you. As in, your 50 mm lens will give
the field of view which habit makes you expect from a 75 mm. But the
focal length, which is an inherent characteristic of the lens. doesn't
change.
Reply With Quote
  #6  
Old 04-18-2007, 05:08 PM
King Sardon
 
Posts: n/a
Default Re: 35mm SLR lenses on digital

On Wed, 18 Apr 2007 15:16:57 GMT, "Jürgen Exner"
<jurgenex@hotmail.com> wrote:

>Oscar wrote:
>> What I don't understand is the way the lenses are now described
>>
>> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
>> film days, understand.
>>
>> All new lenses now seem to be marketed this way, but what if you
>> already have lenses which are from the 35mm film days. Does it mean
>> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
>> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
>> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
>> somebody please help.

>
>For me the easiest way is to remember that what is stamped on the barrel is
>standardized for 35mm film. That means, if you are using that D80 kit lens
>(18-70mm) on a 35mm film camera than you will get an 18-70mm zoom lens.
>
>Now, compared to 35mm film the D80 has a conversion factor of 1.5. That
>means that because of the smaller sensor compared to film this lens when
>used on a D80 has a zoom range of 18x1.5-70x1.5 which equals 27-105mm.
>Same with your old lenses. 35-70 on 35mm film times 1.5 on the D80 equals
>52-105mm.
>
>Unfortunately this conversion is necessary because different cameras have
>different sensors dimensions and therefore different conversion factors,
>e.g. if you were to use this D80 kit lens on some other camera you probably
>end up with slightly different numbers. The one thing to remember is that
>what is stamped on the lens is always for 35mm film.


Focal length is a property of the lens and does not change, no matter
what system you mount it on. But because the image circle is cropped
more in small sensor systems, the FIELD OF VIEW changes, AS THOUGH the
focal length changed, compared to 35mm.

What is stamped on the lens is a property of the lens and does not
change.

It's like taking a medium format lens (for instance a Hasselblad 80mm
lens) and putting it on a 35mm camera. On the 35mm, it behaves like an
80mm lens! But its field of view is different than when it was on the
'Blad.

KS
Reply With Quote
  #7  
Old 04-18-2007, 06:19 PM
C J Campbell
 
Posts: n/a
Default Re: 35mm SLR lenses on digital

On 2007-04-18 07:59:14 -0700, Oscar <a_h_1969@hotmail.com> said:

> Hi,
>
> I've owned a Nikon F401s for many years and always enjoyed using it,
> but with the onset of digital cameras my SLR was assigned to the
> cupboard in favour of a couple of super zoom digital cameras. Anyway
> I now feel the need to change away from these back to a proper SLR and
> have been looking at the Nikon D40, D40x and D80.
>
> I already own three lenses form my SLR days and I know if I brought
> either of the D40 models these lenses will not auto focus.
>
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.
>
> Please don't turn this message in to a debate over which camera is the
> best as there are loads of these around, I know the pitfalls of the
> D40 models over the D80.
>
> Thanks
>
> Oscar


An 35-70mm lens is a 35-70mm lens, no matter what camera it is on.

What they are saying is that since the sensor in a digital camera is
smaller than a frame of 35mm film, then the part of the image circle
that actually gets recorded is smaller. It is like taking a 35mm slide
and just keeping the middle part of it.

The multiplier is appoximately 1.5, which makes it easy. 28mm now
records the same size image as a 42mm lens did. It isn't any sharper;
it is just as if you cropped the middle out of all your 35mm pictures.

Your old lenses will work just as they always did, only now your wide
angle lenses will not seem as wide as they once were, and your
telephoto lenses will seem more powerful. They aren't, but you just
don't get to see the entire image they are capable of producing.

This has its good and bad points. The bad is that you are now forced to
use an APS size film format, complete with all of its limitations in
resolution. The good is that the center part of the image on your old
lenses was the sharpest part anyway. So you have lost the fuzzy edges,
the vignetting, and all the other problems you remember from film days.
The manufacturers don't want you to miss out on those, though, so Nikon
makes "DX" lenses that bring back the vignetting, if not the less sharp
edges. I say you don't need 'em. Use your old lenses.
--
Waddling Eagle
World Famous Flight Instructor

Reply With Quote
  #8  
Old 04-18-2007, 07:17 PM
hanshend@gmail.com
 
Posts: n/a
Default Re: 35mm SLR lenses on digital

On Apr 18, 7:59 am, Oscar <a_h_1...@hotmail.com> wrote:
> Hi,
>
> I've owned a Nikon F401s for many years and always enjoyed using it,
> but with the onset of digital cameras my SLR was assigned to the
> cupboard in favour of a couple of super zoom digital cameras. Anyway
> I now feel the need to change away from these back to a proper SLR and
> have been looking at the Nikon D40, D40x and D80.
>
> I already own three lenses form my SLR days and I know if I brought
> either of the D40 models these lenses will not auto focus.
>
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.
>
> Please don't turn this message in to a debate over which camera is the
> best as there are loads of these around, I know the pitfalls of the
> D40 models over the D80.
>
> Thanks
>
> Oscar


The way I remember this is to imagine the size of the sensor against
the size of the film frame. As the sensor is only 2/3 the size of the
35mm film frame, it only "sees" the center 2/3 of the image that is
thrown onto the "backplane" of the camera. i.e. Imagine that the outer
1/3 of the image falls beyond the outside edges of the digital sensor.
So the effect is the same as if you had zoomed in on the center 2/3 of
a 35mm film frame. (much like "digital zoom" works on P&S digital
cameras). So the effect is the same as if you had zoomed 1.5 times
with a 35mm camera.

HTH.

/M

Reply With Quote
  #9  
Old 04-18-2007, 07:23 PM
Neil Harrington
 
Posts: n/a
Default Re: 35mm SLR lenses on digital


"Oscar" <a_h_1969@hotmail.com> wrote in message
news:1176908354.940308.110210@o5g2000hsb.googlegro ups.com...
> Hi,
>
> I've owned a Nikon F401s for many years and always enjoyed using it,
> but with the onset of digital cameras my SLR was assigned to the
> cupboard in favour of a couple of super zoom digital cameras. Anyway
> I now feel the need to change away from these back to a proper SLR and
> have been looking at the Nikon D40, D40x and D80.
>
> I already own three lenses form my SLR days and I know if I brought
> either of the D40 models these lenses will not auto focus.
>
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.


The 1.5 is a multiplier. Some have objected to the term "multiplier" on the
grounds that the actual focal length is not changed; your lens is still
35-70mm as it always was. Nevertheless, the 1.5x lens factor does mean that
in most respects your 35-70 becomes *equivalent* to a 52.5-105mm lens on a
35. The only reason it's commonly expressed this way is that most of us are
familiar with focal lengths on a 35mm camera. It is useful to have some
standard for visualizing the effects of different focal lengths on angle of
view, and 35mm is that standard because it's been around so long.


>
> Please don't turn this message in to a debate over which camera is the
> best as there are loads of these around, I know the pitfalls of the
> D40 models over the D80.


Not much to debate anyway, since you already know about the autofocus issues
with older lenses on the D40 models.. The D40, D40x and D80 are all top
choices in their respective classes.

Neil


Reply With Quote
  #10  
Old 04-18-2007, 10:53 PM
Jim
 
Posts: n/a
Default Re: 35mm SLR lenses on digital


"Oscar" <a_h_1969@hotmail.com> wrote in message
news:1176908354.940308.110210@o5g2000hsb.googlegro ups.com...
> Hi,
>
> I've owned a Nikon F401s for many years and always enjoyed using it,
> but with the onset of digital cameras my SLR was assigned to the
> cupboard in favour of a couple of super zoom digital cameras. Anyway
> I now feel the need to change away from these back to a proper SLR and
> have been looking at the Nikon D40, D40x and D80.
>
> I already own three lenses form my SLR days and I know if I brought
> either of the D40 models these lenses will not auto focus.
>
> What I don't understand is the way the lenses are now described
>
> ie the kit lenses on the D80 is 18-70mm which equals 27-105mm in 35mm
> film days, understand.
>
> All new lenses now seem to be marketed this way, but what if you
> already have lenses which are from the 35mm film days. Does it mean
> the lens will be as it says on the barrel ie 35-70mm will be 35-70mm
> or will it be multiplied 1.5 so will be 52.5-105mm or do you divide by
> 1.5 so it becomes 23.3-46.6mm. This is the bit I'm unsure of can
> somebody please help.
>
> Please don't turn this message in to a debate over which camera is the
> best as there are loads of these around, I know the pitfalls of the
> D40 models over the D80.
>
> Thanks
>
> Oscar
>

It is the angle of view that changes. So, a 105mm lens on my D70 has the
same angle of view as a 150mm lens on my F3.
Jim


Reply With Quote
Sponsored Links
Fix your Windows Problems - FAST.
FREE Safe Scan Registry Check. Locate & Fix Errors in Minutes!
Reply


Thread Tools
Display Modes



All times are GMT. The time now is 12:00 AM.


Powered by vBulletin® Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.1.0
© 2004 - 2007 Web-S-Sense Pty. Ltd. Usenet and forums posts © their respective authors.
Ad Management by RedTyger