Depth of field

Another question about the Sigma 20mm 1.8 (I just cannot afford the Canon
17-40L).

If I use f1.8 from a distance of around 20' from my subject would a group
shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

--
rda
www.rdaphoto.co.uk

rda wrote:
Another question about the Sigma 20mm 1.8 (I just cannot afford the
Canon 17-40L).

If I use f1.8 from a distance of around 20' from my subject would a
group shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

If they were all the same distance from the lens they should all be in
focus, there are a lot of other factors related to sharpness.

If they were standing one behind the other a couple of feet apart, then
the answer is you would need to stop down.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

rda wrote:
Another question about the Sigma 20mm 1.8 (I just cannot afford the
Canon 17-40L).

If I use f1.8 from a distance of around 20' from my subject would a
group shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

If they were all the same distance from the lens they should all be in
focus, there are a lot of other factors related to sharpness.

If they were standing one behind the other a couple of feet apart, then
the answer is you would need to stop down.

--
Joseph Meehan

26 + 6 = 1 It's Irish Math

any use ? http://www.dofmaster.com/dofjs.html

"rda" wrote in message
...
Another question about the Sigma 20mm 1.8 (I just cannot afford the Canon
17-40L).

If I use f1.8 from a distance of around 20' from my subject would a group
shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

--
rda
www.rdaphoto.co.uk

any use ? http://www.dofmaster.com/dofjs.html

"rda" wrote in message
...
Another question about the Sigma 20mm 1.8 (I just cannot afford the Canon
17-40L).

If I use f1.8 from a distance of around 20' from my subject would a group
shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

--
rda
www.rdaphoto.co.uk

"dylan" wrote in message
...
any use ? http://www.dofmaster.com/dofjs.html


WOW, great link.

It would seem that for 20' the depth of field would be from 13.2' - 41.2'.

Thanks

--
rda
www.rdaphoto.co.uk - comments welcomed (on the photos, I know the site is
crap)

"dylan" wrote in message
...
any use ? http://www.dofmaster.com/dofjs.html


WOW, great link.

It would seem that for 20' the depth of field would be from 13.2' - 41.2'.

Thanks

--
rda
www.rdaphoto.co.uk - comments welcomed (on the photos, I know the site is
crap)

I am looking into this lens myself, and have a question or two for the
group.

I have a D70 with the following lenses (18-70mm 3.5/4.5 DX, 70-300 4/5.6 ED,
28mm 3.5 PC, Sigma 12-24mm 4.5/5.6)

I was looking at adding the Sigma 20mm 1.8 to cover me in low-light
situations where my SB-800 flash would be frowned upon (such as in a
Cathedral).

I should mention at this point that I shoot architecture 95% of the time,
where its important for great sharpness and elimination of depth of field
(not a problem set to infinity focus). However, with this lens, i want to
get into artistic and portrait photography.

Is this a wise choice?

Thanks in advance.


"rda" wrote in message
...
Another question about the Sigma 20mm 1.8 (I just cannot afford the Canon
17-40L).

If I use f1.8 from a distance of around 20' from my subject would a group
shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

--
rda
www.rdaphoto.co.uk

I am looking into this lens myself, and have a question or two for the
group.

I have a D70 with the following lenses (18-70mm 3.5/4.5 DX, 70-300 4/5.6 ED,
28mm 3.5 PC, Sigma 12-24mm 4.5/5.6)

I was looking at adding the Sigma 20mm 1.8 to cover me in low-light
situations where my SB-800 flash would be frowned upon (such as in a
Cathedral).

I should mention at this point that I shoot architecture 95% of the time,
where its important for great sharpness and elimination of depth of field
(not a problem set to infinity focus). However, with this lens, i want to
get into artistic and portrait photography.

Is this a wise choice?

Thanks in advance.


"rda" wrote in message
...
Another question about the Sigma 20mm 1.8 (I just cannot afford the Canon
17-40L).

If I use f1.8 from a distance of around 20' from my subject would a group
shot be sharp, or would I have to stop down?

Sorry to bother you guys all the time.


Happy New Year !

--
rda
www.rdaphoto.co.uk

"skroob" wrote in message
...
I am looking into this lens myself, and have a question or two for the
group.

I have a D70 with the following lenses (18-70mm 3.5/4.5 DX, 70-300 4/5.6
ED,
28mm 3.5 PC, Sigma 12-24mm 4.5/5.6)

I was looking at adding the Sigma 20mm 1.8 to cover me in low-light
situations where my SB-800 flash would be frowned upon (such as in a
Cathedral).

I should mention at this point that I shoot architecture 95% of the time,
where its important for great sharpness and elimination of depth of field
(not a problem set to infinity focus). However, with this lens, i want to
get into artistic and portrait photography.

Is this a wise choice?


I found a few sample images taken with this lens on pbase.
http://search.pbase.com/search?q=20m...ch+Photos&c=sp

Note, only some are taken with the Sigma.



--
rda
www.rdaphoto.co.uk comments welcome (on the photos, the site is crap)