MF resolution question

(Faisal Bhua) wrote in message . com...
Hello,

I have a question for the folks using medium format. My question is,
does 35mm give identical result to MF up to 8R (8x10) prints?

No, 35mm does not give identical results at any size, except postage
stamp.

So is there any justification for using MF if 8R is the maximum size
you print?

Of course MF will provide superior reslts, if all else is equal. It
frequently is not.

I've read MF guys claiming that old Yashica TLRs
outperforming Nikon SLRs, so I'd like to see some hard evidence behind
this. Feel free to point out any errors I've made ? I'm new at this
:-) Also, is film grain a factor?

Yes, of course grain is a factor.

Generally, prints from MF negative look better. The lenses for 35mm and MF
(these days) have similar resolutions, and you get effectively about 50
lines per millimeter (1270 dpi) with reasonable contrast. An 8X enlargement
from 35mm is about 160 dpi, while a 5X enlargement from a small MF negative
is about 250 dpi. That's quite a difference. The actual resolution you get
(or need for sharp looking pictures) may vary with the camera, lens,
technique, film, or circumstances, but these figures are typical and
representative. The bigger negative is an advantage, even for an 8X10
print.

"Faisal Bhua" wrote in message
om...
Hello,

I have a question for the folks using medium format. My question is,
does 35mm give identical result to MF up to 8R (8x10) prints? The math
seems to point that way - here's how:

35mm frame size = 24x36 mm sq = 1.339203 sq inch
Given, a 300 dpi print is considered to be a "museum quality" print.
8x10 print = 8x10x(300)^2 = 7,200,000
Therefore, scan dpi for 35 mm film = sqrt (7,200,000 / 1.339203) =
2319 dpi

Now, 35mm film is supposed to have a theoretical resolution of 4000
dpi. That may be a matter of opinion, but it's certainly more then
2319 dpi.

So is there any justification for using MF if 8R is the maximum size
you print? I've read MF guys claiming that old Yashica TLRs
outperforming Nikon SLRs, so I'd like to see some hard evidence behind
this. Feel free to point out any errors I've made - I'm new at this
:-) Also, is film grain a factor?

About me: beginner, shooting b&w in Minolta X-700, I make my own
prints. Eying MF (esp. TLRs) gear recently.

Hi

Again total system detail inputs are

1. Focal length
2. Resolution
3. Distance

Film size has nothing to do with image detail.

Example, take two wedding photographers photographing a wedding party at 20
feet. One using a Hasselblad with a 50mm lens and 160 ASA film. The other
photographer using a Nikon with a 50mm lens and that same 160 ASA film.

The detail in the dress will be exactly the same. The only real difference is
the Hasselblad photographer images more people in the wedding party because of
the wider angle.

So now play with the math.

Larry

(Hemi4268) wrote in message ...
Hi

Again total system detail inputs are

1. Focal length
2. Resolution
3. Distance

Film size has nothing to do with image detail.

Example, take two wedding photographers photographing a wedding party at 20
feet. One using a Hasselblad with a 50mm lens and 160 ASA film. The other
photographer using a Nikon with a 50mm lens and that same 160 ASA film.

The detail in the dress will be exactly the same.

No, it won't. The Nikon lens will have greater sharpness in its
coverage area because lenses designed to cover only the 24 x 36 mm
frame can be corrected better than the wide-angle design for a 60x60mm
format. Take the 24x36mm section of the Hasselblad negative, and the
Nikon will blow it away.

The only real difference is
the Hasselblad photographer images more people in the wedding party because of
the wider angle.

So now play with the math.

Larry

No, it won't.

Sorry but yes it will. Equal lens, equal distance, equal resolution means
equal detail.

Larry

Hemi4268 wrote:

No, it won't.

Sorry but yes it will. Equal lens, equal distance, equal resolution means
equal detail.

Larry

Absolutely. An example, take an 80 mm lens for a Hasselblad, and use a mount
adapter to place it onto a Nikon SLR. Using the same film in the 35 mm Nikon,
and the Hasselblad, an identically sized slice from either film (24 by 36 mm)
should show exactly the same resolution (detail).

However, in practice not even all 50 mm lenses for various 35 mm systems have
equal resolution, nor do all 80 mm lenses for medium format have the same
resolution. While the differences might be slight, or barely perceptible,
they will always be there.

Outside of using your medium format lenses on 35 mm cameras via mount
adapters, the problem is that there are not equal lenses. Only Contax has an
easy solution of using the same 645 lenses on their N body for 35 mm. All
other companies lenses are not equal, and comparing focal length only is
overly simplistic.

Ciao!

Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com

Subject: MF resolution question
From: Gordon Moat
Date: Mon, Dec 8, 2003 6:19 PM
Message-id:

Hemi4268 wrote:

No, it won't.

Sorry but yes it will. Equal lens, equal distance, equal resolution means
equal detail.

Larry

Absolutely. An example, take an 80 mm lens for a Hasselblad, and use a mount
adapter to place it onto a Nikon SLR. Using the same film in the 35 mm Nikon,
and the Hasselblad, an identically sized slice from either film (24 by 36
mm)
should show exactly the same resolution (detail).

However, in practice not even all 50 mm lenses for various 35 mm systems
have
equal resolution, nor do all 80 mm lenses for medium format have the same
resolution. While the differences might be slight, or barely perceptible,
they will always be there.

Outside of using your medium format lenses on 35 mm cameras via mount
adapters, the problem is that there are not equal lenses. Only Contax has
an
easy solution of using the same 645 lenses on their N body for 35 mm. All
other companies lenses are not equal, and comparing focal length only is
overly simplistic.

Ciao!

Gordon Moat

Don't Pentax users have the ability via an adapter, to also use their 645 and
67 lenses on their 35mm film (and DSLR) bodies?

Regards,

Check out my photos at "LEWISVISION":

http://members.aol.com/Lewisvisn/home.htm

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However, in practice not even all 50 mm lenses for various 35 mm systems have
equal resolution

Actually they do. What you mean to say is not all 35mm bodies have the exact
same mirror focus position.

A perfect lens will have the following resolution and depth of focus in noon
summer sun.

f-1 2000 lp/mm 1 micron of DOF
f-2 1000 2
f-4 500 16
f-8 250 64
f-16 125 256

You can see that at f-4, the mirror must be within 16 microns to be perfect.

A human hair is 400 microns.

Typical standard for most good camers is about + or - 50 microns for the mirror
position. You have to get to about f-8 for everything to be equal.

Larry

(Hemi4268) wrote in message ...
No, it won't.

Sorry but yes it will. Equal lens, equal distance, equal resolution means
equal detail.

Larry

Don't let physics get in your way, pal...

Gordon Moat wrote in message ...
Hemi4268 wrote:

No, it won't.

Sorry but yes it will. Equal lens, equal distance, equal resolution means
equal detail.

Larry

Absolutely.

Absolutely false

An example, take an 80 mm lens for a Hasselblad, and use a mount
adapter to place it onto a Nikon SLR. Using the same film in the 35 mm Nikon,
and the Hasselblad, an identically sized slice from either film (24 by 36 mm)
should show exactly the same resolution (detail).

False

However, in practice not even all 50 mm lenses for various 35 mm systems have
equal resolution, nor do all 80 mm lenses for medium format have the same
resolution. While the differences might be slight, or barely perceptible,
they will always be there.

True, contradicting the two prior statements.

Outside of using your medium format lenses on 35 mm cameras via mount
adapters, the problem is that there are not equal lenses. Only Contax has an
easy solution of using the same 645 lenses on their N body for 35 mm. All
other companies lenses are not equal, and comparing focal length only is
overly simplistic.

Ciao!

Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com