First contact prints done. Problem with light uniformity.

I have finally done my first contact prints... and many questions arose
from that. Much more than after the development of 1st film!!

Here is the first one.

The light coming from the enlarger is NOT constant all over the lighted
area. I have noticed that after beeing suggested to pay attention to the
visibility of the sprocket holes for reference.

If in the center of the sheet are not visible they are at the borders. I
am assuming that there is at least 1/2 or even 1 stop difference.

Considering that I have an Durst M601 with Componon 50mm f2.8 is this
normal? Corrective actions??

Ciao,
Fabio BERETTA
Lecco - Italy

Fabio BERETTA wrote in news:bRbWb.217746
:


Considering that I have an Durst M601 with Componon 50mm f2.8 is this
normal? Corrective actions??

Ciao,
Fabio BERETTA
Lecco - Italy



Light falloff at the edges. You need to use a smaller aperature, like f/8
or f/11.

Bob

Sounds to me like he needs to install the correct condensors/mixer for the
lens...
denny
"bob" 1xwj.ReverseThePartBeforeTheDot@bellsouthnet wrote in message
...
Fabio BERETTA wrote in news:bRbWb.217746
:


Considering that I have an Durst M601 with Componon 50mm f2.8 is this
normal? Corrective actions??

Ciao,
Fabio BERETTA
Lecco - Italy



Light falloff at the edges. You need to use a smaller aperature, like f/8
or f/11.

Bob

I'm not familiar with the M601... Does it have a condenser head, or a light
mixing box? Whichever it has, is the correct set for 35mm film/lens
installed? If the correct set is installed for the lens you are using, did
you have the 35mm negative carrier inserted during your white light exposure
for the contact prints?

While it is intuitive that the incorrect condenser or mixer box wiill cause
light fall off problems, it is not as intuitive that leaving the correct
negative carrier out of the light path will cause unevenness of the light -
which it will...

Other issues, such as the light bulb not being properly aligned, a wadded up
paper or filter somewhere in the light path, dirty or hazy lens, etc., can
be explored also...
Good hunting...
denny
"Fabio BERETTA" wrote in message
...
I have finally done my first contact prints... and many questions arose
from that. Much more than after the development of 1st film!!

Here is the first one.

The light coming from the enlarger is NOT constant all over the lighted
area.

In article ,
says...
I have finally done my first contact prints... and many questions arose
from that. Much more than after the development of 1st film!!

Here is the first one.

The light coming from the enlarger is NOT constant all over the lighted
area. I have noticed that after beeing suggested to pay attention to the
visibility of the sprocket holes for reference.

If in the center of the sheet are not visible they are at the borders. I
am assuming that there is at least 1/2 or even 1 stop difference.

Considering that I have an Durst M601 with Componon 50mm f2.8 is this
normal? Corrective actions??

Ciao,
Fabio BERETTA
Lecco - Italy


Raise the enlarger head so that the light on the paper is bigger. This
way you will only use the center of the light pattern and avoid the
falloff near the corners. Just increase the exposure time to compensate.
You should also use f8 or f11.

--
Robert D Feinman

Landscapes, Cityscapes, Panoramas and Photoshop Tips
http://robertdfeinman.com

or perhaps put in the correct mask in the carrier since the 50mm will not
cover the entire area of the 6x6 glass

--
darkroommike

----------
"Dennis O'Connor" wrote in message
...
Sounds to me like he needs to install the correct condensors/mixer for the
lens...
denny
"bob" 1xwj.ReverseThePartBeforeTheDot@bellsouthnet wrote in message
...
Fabio BERETTA wrote in news:bRbWb.217746
:


Considering that I have an Durst M601 with Componon 50mm f2.8 is this
normal? Corrective actions??

Ciao,
Fabio BERETTA
Lecco - Italy



Light falloff at the edges. You need to use a smaller aperature, like
f/8
or f/11.

Bob

I have used f11!


bob wrote:
Fabio BERETTA wrote in news:bRbWb.217746
:


Considering that I have an Durst M601 with Componon 50mm f2.8 is this
normal? Corrective actions??

Ciao,
Fabio BERETTA
Lecco - Italy




Light falloff at the edges. You need to use a smaller aperature, like f/8
or f/11.

Bob

Lens was clean I bought the componon because I had proble with fungus
with my previous lens.

In the head there a
- light bulb
- a mirror
- two thick lenses simmetrically installed with the convex part in the
middle
- the 50mm lens attached to a flange

I have tryied to adjust bulb height in order to maximize the light but
it reaches the top of the head and cannot be adjusted more

I let the negative carrier installed partly reducing the area with the
moveable masks.

Dennis O'Connor wrote:
I'm not familiar with the M601... Does it have a condenser head, or a light
mixing box? Whichever it has, is the correct set for 35mm film/lens
installed? If the correct set is installed for the lens you are using, did
you have the 35mm negative carrier inserted during your white light exposure
for the contact prints?

While it is intuitive that the incorrect condenser or mixer box wiill cause
light fall off problems, it is not as intuitive that leaving the correct
negative carrier out of the light path will cause unevenness of the light -
which it will...

Other issues, such as the light bulb not being properly aligned, a wadded up
paper or filter somewhere in the light path, dirty or hazy lens, etc., can
be explored also...
Good hunting...
denny
"Fabio BERETTA" wrote in message
...

I have finally done my first contact prints... and many questions arose
from that. Much more than after the development of 1st film!!

Here is the first one.

The light coming from the enlarger is NOT constant all over the lighted
area.

"Fabio BERETTA" wrote


I have tryied to adjust bulb height in order to maximize the light but
it reaches the top of the head and cannot be adjusted more

Is this the height of the bulb within the head, or the height of the
head above the easel?

The location of the bulb within the head is to maximize the evenness of
the light, not the intensity.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.

Height of the bulb within the head... that's probably the mistake!!

Now is there any method to correctly estimate if evenness of the light
has been reached?

Nicholas O. Lindan wrote:
"Fabio BERETTA" wrote



I have tryied to adjust bulb height in order to maximize the light but
it reaches the top of the head and cannot be adjusted more


Is this the height of the bulb within the head, or the height of the
head above the easel?

The location of the bulb within the head is to maximize the evenness of
the light, not the intensity.