Pentax 6x7 Mirror/Shutter Shake Test1 completed
david_...@my-deja.com
on photographyreview.com complaining about
mirror/shutter vibrations in the Pentax 6x7. It
all kind of scared me, but I decided to buy the
camera anyway. I got a near-mint older version
with mirror lock-up, TTL prism, and 105/2.4
lens. I just recieved it yesterday and the first
thing I wanted to do is test this "mirror" shake
syndrome. I grabbed a new roll of TMax 400, got
a fresh battery, and did this:
- Hand held, without locking mirror, from 3.5
feet away. Focused on a set of tassles hanging
from a flag, indoors, pretty low light. Set the
camera's ISO at 1600.
- 1/15 sec @f/11
- 1/30 sec @f/8
- 1/60 sec @f/5.6
- 1/125 sec @f/4
- 1/250 sec @f/2.4
- Developed in TMax Developer and scanned into
Photoshop 5.5 with Kodak Professional RFS 3570
Film Scanner (a no bullsh*t scanner).
Results---- I could see on the negatives that
the 1/15 second exposure had camera movement.
Once scanned in and compared, the 1/30 sec looked
as sharp as the 1/250 sec exposure. Of course
the others did too. The 1/15 sec was the only
exposure that looked affected by the
mirror/shutter vibrations.
Conclusion---- First of all, there is a Test2 in
progress. It will be to test the vibrations for
an object far away. But about this test1, what
can I say? My guess is that the people who
complain either have trouble staying still while
shooting, or their cameras have some kind of
defect. I've read complaints about vibrations
affecting photos in exposures up to 1/125 sec.
NO WAY!
I hope not to eat my words in Test2.
If anyone would like me to send him/her a
pictoral display of Test1, email me at
ro...@mcbbutler.usmc.mil
The display on file is 9"x11" @ 400 dpi. I doubt
anyone would want to recieve an attatchment that
big, so tell me the largest file size (in kb or
mb) you want me to mail, and I'll do it.
Piece,
David
Sent via Deja.com
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David Grabowski
Mirror shake problems , especially with 6x7 slr cameras is not limited
to the Pentax. Also try your tests over again on a tripod, handheld is
actually superior in many cases to tripod mounted shots that are
exposed under 125th second without mirror up . I know for sure my RB
67 Pro S suffers from this without mirror lock up , enough so that
it's useless to shoot from 1/60 down on at least my tripod without
locking up the mirror and at 1/8 sec. the images are not even
salvagable if not using mirror up. I can hand hold acceptably at 60th
sec. though and can only assume hand holding offers more dampening
than tripod mounted will.
By the same token I can handhold fairly well down to 1/30 with a TLR
in 6x6, in many ways I like TLRs over SLR, one being that you can use
a much lighter tripod for slow shutter work. The big downfall is not
viewing through the taking lens but these are still very viable tools
IMO .
Since you now have a Pentax 67 and probably will tripod mount it at
some point in time, be forwarned about springy camera shake on a
tripod. And my suggestion would be to get used to a cable release , as
well as the mirror up function. But don't take my word for this at
all, just run your own tests, it will be obvious enough soon enough.
David Grabowski
david_...@my-deja.com
Thanks for the comment, I'll test the 6x7 mounted
on a tripod too. I really hope you're wrong though. Well, I guess
having to lock the mirror up wouldn't be that bad if I'm setting up a
shot as unspontaneoius as on a tripod. I was really concerned with
handheld shooting. I'm interested mainly in available light shooting,
so if I would have gotten vibration-ruined photos at 1/125 or even 1/60
sec. I would be been seriously pissed off.
-David
In article <3a4deeb9....@newshost.capecod.net>,
Mike
to deal with also.
<david_...@my-deja.com> wrote in message
news:92loat$6o$1...@nnrp1.deja.com...
Photo0003
under 30th. handholding and it is never a problem with a 30th. flash sync. It
is a heavy camera though. Please send me you photo. I would enjoy seeing it.
Marc Stewart
phot...@aol.com
jjs
david_...@my-deja.com wrote:
With all respect, David, I'm afraid that not much can be made of your
tests because we see no metrics concerning sharpness - just your
opinion, and the change of f-stop for each picture further confuses the
issue. Even a simple res-chart would be more helpful than an
impressionistic opinion. Try another test: Same light, same subject,
but on a tripod - and all at one f-stop, say F11.
Many people who first begin with MF or move to MF from 35mm are happily
surprised by their early images, thinking them quite sharp, but after a
while begin to see what sharpness is truly possible. I suggest you are
not being as critical as you could be.
...but sharpness is not everything. Enjoy.
Joachim Inkmann
, and the change of f-stop for each picture further confuses the
> issue. Even a simple res-chart would be more helpful than an
> impressionistic opinion. Try another test: Same light, same
> subject, but on a tripod - and all at one f-stop, say F11.
jjs, how can you make a comparison of the shutter shakes induced by
_different_ exposure times holding light and f-stop (and I assume
film type) constant? And why using a tripod when the interest focuses on
hand-holding? I think David's procedure is quite reasonable.
Joachim
david_...@my-deja.com
Bro, I think you missed the point. I was just afraid that if ...I...
(hence, my opinion) were to hand-hold my Pentax 6x7 and shoot with
shutter speeds below 1/125 sec that the images would be affected by
mirror/shutter vibrations. That was the test. And f stops have
nothing to do with this test. It wasn't a sharpness test, even if I
may have called it that (sorry if I did). It was a camera-movement
test. I'm pretty much a beginner photographer, so I could be
misconceiving this whole subject. I wasn't trying to write anything in
stone, just report what I found.
David.
In article <92nhqo$7o0$1...@nnrp1.deja.com>,
Rick Rieger
you have and what additional exposure values are obtained by stacking them.
RR
"Joachim Inkmann" <joachim...@uni-konstanz.de> wrote in message
news:3A4F4EEA...@uni-konstanz.de...
jjs
david_...@my-deja.com wrote:
> Bro, I think you missed the point. I was just afraid that if ...I...
> (hence, my opinion) were to hand-hold my Pentax 6x7 and shoot with
> shutter speeds below 1/125 sec that the images would be affected by
> mirror/shutter vibrations. That was the test.
Interesting that you think that shutter and mirror vibration would hurt
a hand-held shot. What are you expecting, recoil?
david_...@my-deja.com
OK, smartass; Yes, after reading on many sites that "handheld
shots slower than 1/125 sec would be affected by mirror/shutter
vibrations", I, low and behold, thought that handheld shots slower than
1/125 sec would be affected by mirror/shutter vibrations. Are you
missing something, or do you just intend to argue regardless?
David
In article <92p1d5$9hs$1...@nnrp1.deja.com>,
annqlee
<david_...@my-deja.com> wrote in message
news:92kms6$7td$1...@nnrp1.deja.com...
David,
Thanks for the info. I was wondering how did you decifer that it was
the mirror shake instead of your hand holding at 1/15? Maybe you should
take some pics with a tripod just to verify that it is the mirror shake .
Your focusing distance is quite close(magn) and compounded with a 105mm
lens, it is reasonable to suspect hand-holding problems.
Ann
jjs
david_...@my-deja.com wrote:
> JJS,
> OK, smartass; Yes, after reading on many sites that "handheld
> shots slower than 1/125 sec would be affected by mirror/shutter
> vibrations", I, low and behold, thought that handheld shots slower
than
> 1/125 sec would be affected by mirror/shutter vibrations. Are you
> missing something, or do you just intend to argue regardless?
So, for give me already. The idea of the shutter/mirror being the
significant element in Hand Held shooting was simply incredible to me.
And we move on with the myths. I hear that the Pentax 67 shutter shake
will make your browsers explode.
See:http://wind.winona.msus.edu/~stafford/s/p1.html
jjs
"Mike" <NEDS...@email.msn.com> wrote:
> Dont forget that in the Pentax 67 you have a hell of a focal plane
shutter
> to deal with also.
And be careful with any camera with large glass. Bird strikes, you
know. But there are significant advantages to the P67. I throw a couple
in to the back of my pickup in the winter for traction. And best put a
lock on the film door. One year I found a family of migrant workers had
moved in.
Paul Skelcher
> > Bro, I think you missed the point. I was just afraid that if ...I...
> > (hence, my opinion) were to hand-hold my Pentax 6x7 and shoot with
> > shutter speeds below 1/125 sec that the images would be affected by
> > mirror/shutter vibrations. That was the test.
>jjs <jo...@stafford.net> wrote in message....
> Interesting that you think that shutter and mirror vibration would hurt
> a hand-held shot. What are you expecting, recoil?
When I hand-hold my 6x7, camera shake, the major cause of unsharp images I
would think, is my main convcern. There's no reason why mirror/shutter
vibrations should be any different with the camera hand-held or on a tripod,
so why not test on a tripod and eliminate at least one variable.
Paul
david_...@my-deja.com
I do plan to test it on a tripod also, and eliminating that
variable makes sense, but just to let you know, this whole thing has
kind of been blown out of proportion. Since I was just buying my first
medium format, I was just worried about the rumors that any shutter
speed slower than 1/125 second without using mirror lock up would cause
unusable images due to mirror/shutter vibrations.
-David
In article <92q7nt$2e5$1...@bob.news.rcn.net>,
Paul Skelcher
http://www.smu.edu/~rmonagha/mf/index.html
Enjoy your 6x7!
Paul
david_...@my-deja.com
In article <92q547$fg$1...@nnrp1.deja.com>,
ajacobs2
Peter Caplow
When I read the original post, I felt the same way you did. Then I read the
umpteen replies which all danced around the subject to one degree or
another. Yours was the first one that clearly addressed the real issue. Of
course David should also take some shots with mirror lockup to see how much
shake is induced by that giant focal plane shutter.
Peter Caplow
jjs
test of the human factor, not the camera, so I suggest he specify the
human parameters - his body at the time of making the hand-held photos:
caffeen content, body type, age, heart rate, basic tremor rate, and so
forth. :) Next could be the psychological, such as critical quality of
his judgement. Perhaps he simply has lower expectations and less
experience than others have.