Unsharp after burning

(kpphoto) wrote in message om...
up from a 6.45 neg, I have areas that go out of focus almost like a

"areas" that are sometimes but not always blurred... sounds like you
are using a glassless carrier.

doubling of the image over the original.

If the neg pops (forth or back) between basic and additional exposure
the image will be blurred the way you describe it.

In article ,
(Stefan Kahlert) wrote:

(kpphoto) wrote in message om...
up from a 6.45 neg, I have areas that go out of focus almost like a

"areas" that are sometimes but not always blurred... sounds like you
are using a glassless carrier.

doubling of the image over the original.

If the neg pops (forth or back) between basic and additional exposure
the image will be blurred the way you describe it.

Yep As stated;
120 film on longer exposures is suseptable to negative popping
and that would cause the problem described. I've never seen it happen
because 99% of my negatives print around 15 seconds at mid range on the
apeture scale.
--
LF Website @ http://members.verizon.net/~gregoryblank

"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

In article ,
(Stefan Kahlert) wrote:

(kpphoto) wrote in message om...
up from a 6.45 neg, I have areas that go out of focus almost like a

"areas" that are sometimes but not always blurred... sounds like you
are using a glassless carrier.

doubling of the image over the original.

If the neg pops (forth or back) between basic and additional exposure
the image will be blurred the way you describe it.

Yep As stated;
120 film on longer exposures is suseptable to negative popping
and that would cause the problem described. I've never seen it happen
because 99% of my negatives print around 15 seconds at mid range on the
apeture scale.
--
LF Website @ http://members.verizon.net/~gregoryblank

"To announce that there must be no criticism of the President,
or that we are to stand by the President, right or wrong,
is not only unpatriotic and servile, but is morally treasonable
to the American public."--Theodore Roosevelt, May 7, 1918

On Thursday 04 November 2004 14:42, kpphoto wrote:

I am having a problem with sharpness when I am burning in an area of
a print. I am using a D5 with a dicro head. On larger prints, 14x14
and up from a 6.45 neg, I have areas that go out of focus almost
like a doubling of the image over the original. The enlarger is
stable & so is the easel. It does not happen all the time. It is
sharp on a straight print. What varieing factor am I overlooking.
The lens is stopped down 4 stops. I use my hands halfway between
the
lens and paper with a large opening than smaller. Is it a form of
diffraction that is causing the image to do this? Has any one had
this happen?

If the change in the image is "large" as you say, this sounds like
negative pop due most likely to heat from the dichroic head. You say
this doesn't happen all the time. Does it happen mostly with longer
rather than shorter burn times? If yes, then it's probably negative
popping. Check that your light head has the heat absorbing glass in
place. The only way to be sure this no longer occurs is to use a
glass carrier, but that of course introduces a whole other set of
problems.

Are you changing the f-stop of the enlarger lens between the primary
exposure and the burn exposure? If yes, you may be experiencing lens
focus shift. This is usually more of a problem with Tessar (4
element) or Trinar (3 element) lenses than with Plasmats (6 element)
ones. In any case, always do the final focus with a grain focuser at
the printing aperture, and to be on the safe side, don't change the
f-stop when burning.

Is your enlarger REALLY stable? Do this test: Put a glass of water
on top of the enlarger head, and have someone walk/stomp around your
apartment or home. Do little vibration rings form in the water?
Does a large vehicle going by outside do the same thing? Rap firmly
with a couple of fingers on the side of the dichroic head. How long
does it take for the water rings to decay? If in any of these tests,
it takes longer than about 20% of your normal print exposure time,
you should consider bracing your enlarger and/or the column. I have
a Beseler 45M which is mounted on a custom-built, free standing bench
on a concrete floor, and it only takes about 2 to 3 seconds for the
water to calm. My base exposure is around 20 seconds.

--
Stefan Patric

On Thursday 04 November 2004 14:42, kpphoto wrote:

I am having a problem with sharpness when I am burning in an area of
a print. I am using a D5 with a dicro head. On larger prints, 14x14
and up from a 6.45 neg, I have areas that go out of focus almost
like a doubling of the image over the original. The enlarger is
stable & so is the easel. It does not happen all the time. It is
sharp on a straight print. What varieing factor am I overlooking.
The lens is stopped down 4 stops. I use my hands halfway between
the
lens and paper with a large opening than smaller. Is it a form of
diffraction that is causing the image to do this? Has any one had
this happen?

If the change in the image is "large" as you say, this sounds like
negative pop due most likely to heat from the dichroic head. You say
this doesn't happen all the time. Does it happen mostly with longer
rather than shorter burn times? If yes, then it's probably negative
popping. Check that your light head has the heat absorbing glass in
place. The only way to be sure this no longer occurs is to use a
glass carrier, but that of course introduces a whole other set of
problems.

Are you changing the f-stop of the enlarger lens between the primary
exposure and the burn exposure? If yes, you may be experiencing lens
focus shift. This is usually more of a problem with Tessar (4
element) or Trinar (3 element) lenses than with Plasmats (6 element)
ones. In any case, always do the final focus with a grain focuser at
the printing aperture, and to be on the safe side, don't change the
f-stop when burning.

Is your enlarger REALLY stable? Do this test: Put a glass of water
on top of the enlarger head, and have someone walk/stomp around your
apartment or home. Do little vibration rings form in the water?
Does a large vehicle going by outside do the same thing? Rap firmly
with a couple of fingers on the side of the dichroic head. How long
does it take for the water rings to decay? If in any of these tests,
it takes longer than about 20% of your normal print exposure time,
you should consider bracing your enlarger and/or the column. I have
a Beseler 45M which is mounted on a custom-built, free standing bench
on a concrete floor, and it only takes about 2 to 3 seconds for the
water to calm. My base exposure is around 20 seconds.

--
Stefan Patric