Sharpness - Mamiya C330

Stefan Patric wrote:


I doubt if your sharpness problem is equipment related, since it doesn't
occur on every image. My guess would be it's something you are or are not
doing. I'll pose some questions to further your investigation.


Its a bit hit and miss but I note on the last couple of films that more are
slightly soft than those who arn't.

Do you need glasses? Bifocals?


Yes, got them, eyes tested regarly and my perscription has barely changed in
years.

Do you use the pop-up magnifier when focusing? You should. All the time,
every time.


Yes. In fact (and this might be part of the problem) when it is too light
out to get a really good idea of what is on the view finder - I put my eye
really close to the magnifier - using it as a crude viewfinder. Hmm, on
reflection - is this it?


Is your focusing screen, mirror and focusing lens clean or loose, etc?
Do you use filters? If you do, the filter needs to be on the focusing
lens when you focus. A filter with 2 air/glass surfaces changes the
optical path which can affect the focus point.


Focusing screen can move, but it seems to rest by defalt on the three small
adjusting screws.

Lately I've been using identical filters on both lenses.

Are any of the "unsharp" pictures shot with the lens wide open or fully
stopped down? This can affect apparent image sharpness due to lens
aberrations, which mostly disappear after stopping down 2 stops, or image
diffusion, which begin to occur as you approach the higher f-stop numbers.
Try to use a moderate f-stop range from at least 2 stops down to 2 stop up
from minimum aperture.


I try and stay somewhere in the middle of the f-stop range unless there is
good reason not to.


Lastly, here's a quick test you can do to check if focus is out due to
problems in the camera. Mount the camera on a tripod facing a blank wall,
level the camera so it is parallel to the wall, place a focusing target of
sufficient size that it fills the viewfinder entirely. I use a page of a
newspaper, which is mostly fine print. Make sure it's absolutely flat to
the wall. No sags or bulges. Evenly illuminate the target either with
natural or artificial light. A large north facing window opposite the
wall, behind the camera will work. You just want the light even and
diffuse. With no film in the camera, open the back and tape a piece of
fine ground glass over the film gate. Make sure the textured side is at
the film plane and pointed toward the lens. If you don't have any ground
glass, substitute any smooth media that will hold the image. Rear screen
projection material is good. In a pinch, I've used a smooth piece of
heavy waxed paper.


That look like a plan - just got to get hold of some ground glass - a friend
had to make some so I'll have a word with him.

Now, with the taking lens wide open, focus on the center of the
focusing target as you normally do. And use the focusing magnifier.
Remove the focusing hood and place it over the film gate to make it easier
to view the projected image. Is it sharp or out? Now, refocus on the film
gate image making it as sharp as you can. Examine the image focused on
the normal viewing screen. Is it in focus? In both cases, if everything
is working properly, the images should have been in focus for both
procedures.

Repeat the test with the taking lens stopped down to a mid-f-stop, f8 is
good. Compare the results.

Now, without changing the set up, make a test carefully focusing in
the normal manner using medium speed b&w film shooting wide open, stopped
down mid-way, and stopped down all the way. That chromogenic b&w film
that can be processed in color chemistry is fine. You just want to check
if things are in focus on film when they are in the viewfinder. Don't make
prints. Examine the film directly with at least an 8X loupe. If images
are out, take your camera and lens to a tech and have it checked it out.

I know that the Mamiya TLR lenses give excellent results having owned a
C-220 and a couple of lenses years ago, that I shot with professionally --
glamour, advertising, editorial, PR, etc. Never received any complaints
from any ADs or editors about "soft" or out of focus images, unless, of
course, they were suppose to be. ;-) The lens(es) you're using are the
black barrel type? Right? Not the chrome ones?

Yes - black barrel. Some light scratches on the lens elements of the 135mm
but not on the others and I can't see a difference. I was sold the 55mm
lens cheap because it had a small scratch on one of the elements - well -
I'll go back to that supplier - it was immaculate and after a lot of very
fine inspection it had a really, really small scratch. I'd have not seen
it if I'd not been told.

Some homework for me now.

Thanks all. I need to do some testing.

Pete

--
http://www.petezilla.co.uk

Peter Chant wrote:
RolandRB wrote:

dropped. Nearly all these camera have added spacer washers and strips
to move the focussing screen up so as to compensate. I think they are
great cameras (I have a few) but you have got to be aware of this
weakness with them and to be on the lookout for a problem with it.

I think they are screws on the C330f?

I haven't got that model but I think that would be a good idea.

camera has never been dropped...next idea?

Hi Peter:

Cape Ann is on the coast of Massachusetts abot 30 mikes north of Boston.
It includes the towns of Gloucester and Rockport.

Jim


Peter Chant wrote:

Jim Hemenway wrote:


Shot several days ago with the C220F:

http://www.half-fast.com/CapeAnn-C220F-12282006/


Nice, need to get out and take some myself!

Where is Cape Ann?

Pete

On Sun, 07 Jan 2007 19:50:53 +0000, Peter Chant wrote:

Stefan Patric wrote:


I doubt if your sharpness problem is equipment related, since it doesn't
occur on every image. My guess would be it's something you are or are not
doing. I'll pose some questions to further your investigation.


Its a bit hit and miss but I note on the last couple of films that more are
slightly soft than those who arn't.

If the frequency of "soft" shots has been increasing over time, this
could be indicative of hardware problems. I'd recommend taking the camera
to a tech, and having it checked out as well as cleaned, adjusted and
lubed.

Do you need glasses? Bifocals?


Yes, got them, eyes tested regarly and my perscription has barely changed in
years.

Any astigmatism? Have friend who has it (and really bad sight anyway),
and he has problems getting a good focus because of it. And he's a pro.
Graduated from Brooks with a degree in photography. He thanks God
everyday for autofocus.

Do you use the pop-up magnifier when focusing? You should. All the
time, every time.


Yes. In fact (and this might be part of the problem) when it is too
light out to get a really good idea of what is on the view finder - I
put my eye really close to the magnifier - using it as a crude
viewfinder. Hmm, on reflection - is this it?

This is the way -- really close to the magnifier -- I always focused my
C-220, so I could see almost the entire field, not just the center. Never
had any focusing problems doing that way. Images always in focus.


Is your focusing screen, mirror and focusing lens clean or loose, etc?
Do you use filters? If you do, the filter needs to be on the focusing
lens when you focus. A filter with 2 air/glass surfaces changes the
optical path which can affect the focus point.


Focusing screen can move, but it seems to rest by defalt on the three
small adjusting screws.

Have a camera tech check that the screen is properly aligned. My C-220
had a fixed screen. So, I never had to worry about it going out of
adjustment.

Lately I've been using identical filters on both lenses.

Okay. Optical paths should be the same for both lenses.


[snip]

I know that the Mamiya TLR lenses give excellent results having owned a
C-220 and a couple of lenses years ago, that I shot with professionally
-- glamour, advertising, editorial, PR, etc. Never received any
complaints from any ADs or editors about "soft" or out of focus images,
unless, of course, they were suppose to be. ;-) The lens(es) you're
using are the black barrel type? Right? Not the chrome ones?

Yes - black barrel. Some light scratches on the lens elements of the
135mm but not on the others and I can't see a difference. I was sold
the 55mm lens cheap because it had a small scratch on one of the
elements - well - I'll go back to that supplier - it was immaculate and
after a lot of very fine inspection it had a really, really small
scratch. I'd have not seen it if I'd not been told.

Good. The black lenses were much better than the older, original chrome
ones. And the 135 was my favorite, most used focal length when I used the
Mamiya TLR. Shot a lot of magazine covers with it.

That small scratch on the 55, if it was off to the side, should not affect
image quality at all. Probably wouldn't even it were dead center on the
front element. Might if on the rear. Keep the lens.

Stef

PRO SHOW_SS wrote:
camera has never been dropped...next idea?

Not that you know of. You can't be certain of this unless you had it
from new and if you did then why didn't you take it back when you
noticed the problem?

Check the edge oif the lens housing like I said and see if the top
touched the camera body before the bottom does when you move it to
infinity focus.

Recently, PRO SHOW_SS posted:

camera has never been dropped...next idea?

Disclaimer: I don't own a C330 (but my dad did).

I think your best shot is to take the advice given regarding checking your
focus by comparing the focal plane view against the focusing screen view.
It is a good, simple method to verify whether the camera is in adjustment.
If it isn't, then your options become a matter of "do it yourself" vs.
CLA. Frankly, I'd just do the latter and get back to shooting photos.

Best regards,

Neil

iT happen like 4 years ago..took it in to get checked...they said
nothing was wrong with it...so i just let it sit.. and this thread got
me thinking of it again...i've owned it since new...its a C330
Professional S

just checked it hits even...its so like new the bellows still makes the
cracklin sound when you open it

i would let it take pics again, but i just don't trust it....to be
honest i have my Hasselblads to fall back on all these years...so the 2
-330's i have will end up on ebay if i can't figure the one out...
hate to see them go , the one i do use is a work horse and has not let
me down since 1987 when i got it new in the box....the problem one was
also bought new in box.....you can't beat them when they work right...no
one can argue that statement..........