[K-M - Sony] Damn! Now let's move on...

"Philip Homburg" <philip DeleteThis @pch.home.cs.vu.nl> wrote:
>>
>>Yep. Irritating, since the AF system will report focus with AF lenses
>>switched to MF mode.
>
> Is that true in general for Canon cameras? I think Nikon cameras always
> report focus information, independent of the kind of lens that is
> attached.

I think we mean the same thing here: when I manually focus my AF lenses in
MF mode, the AF beeps and flashes, on both the 5D and 300D. Kennedy reports
that he doesn't get AF beeps and flashes from the 5D with his OM lenses
mounted.

(I don't own any manual focus 35mm lenses. I'm in the midst of ordering a
shift adapter to use my Mamiya 645 lenses on the 5D, so I'll be able to
report what I find later. But I suspect it'll be the same as Kennedy, whom I
roundly flamed for not seeing the beeps and flashes which I assumed would be
the same with a real MF lens as opposed to a turned off AF lens.)

Pretty funny: Nikon has too long a mount-to-film distance to use odd lenses
but does the right thing with AF if they could, and Canon can use funky
lenses but does the wrong thing with AF. Sigh.

If you are right, though, I will be somewhat surprised, since it means that
the AF system must be operating all the time the camera is on...

David J. Littleboy
Tokyo, Japan
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

In article <dr7kbu$m71$1@nnrp.gol.com>,
David J. Littleboy <davidjl RemoveThis @gol.com> wrote:
>If you are right, though, I will be somewhat surprised, since it means that
>the AF system must be operating all the time the camera is on...

I know how it works in the two Nikon AF cameras I own (the F4 and the D1).
AF reporting is on whenever the light meter is on. Even without any lens
attached (obviously, in that case the camera reports that it doesn't know
what to do).


--
That was it. Done. The faulty Monk was turned out into the desert where it
could believe what it liked, including the idea that it had been hard done
by. It was allowed to keep its horse, since horses were so cheap to make.
-- Douglas Adams in Dirk Gently's Holistic Detective Agency
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

--
----m0o0m
"ah2" <twoie DeleteThis @ah.com.net> wrote in message
news:11tf7lc2josnq00@news.supernews.com...
> "no one noteworthy" <only DeleteThis @the.group> wrote in message
> news:6yABf.226281$V7.211629@news-server.bigpond.net.au...
>
>> You can't consistently hand-hold a 5D without bracing yourself against a
>> rigid object and get clear pictures at less than 1/125 with any lens over
>> 100 mm.
>> The shock of the mirror slapping up is as much a part of the problem as
>> the rebound shudder from the shutter itself.
>
> I truly doubt the mirror slap and shutter have more an effect (hand held)
> than normal human shaking. Heck, if you have a heartbeat, you have camera
> shake.
>
>
Worse... If you are a big coffee or coke drinker, you will have
uncontrollable shakes anyway. Having said this, I have literally hundreds of
photos taken with a rangefinder camera at 1/15th and 1/30 which are sharp. I
also have dozens taken with SLRs at similar shutter speeds that are fuzzed.

At this point, all I can see of value in a SLR is the ability to see through
the lens...
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

In message <11tf7lc2josnq00 DeleteThis @news.supernews.com>,
"ah2" <twoie DeleteThis @ah.com.net> wrote:

>I truly doubt the mirror slap and shutter have more an effect (hand held)
>than normal human shaking. Heck, if you have a heartbeat, you have camera
>shake.

I think that mirror slap is only an issue for people with light grips,
and with tripods. For a firm manual grip, there is too much damping and
too much mass for the camera to move from the tiny little mirror. On a
tripod, however, the mirror slap can resonate and be a real issue,
especially with inexpensive tripods. When I used a Slik tripod a few
years back, I could see the scene shaking much more violently after the
exposure, through the viewfinder, on the tripod, than with the same lens
hand-held.

--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS DeleteThis @no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

"Philip Homburg" <philip.TakeThisOut@pch.home.cs.vu.nl> wrote:
> David J. Littleboy <davidjl.TakeThisOut@gol.com> wrote:
>>If you are right, though, I will be somewhat surprised, since it means
>>that
>>the AF system must be operating all the time the camera is on...
>
> I know how it works in the two Nikon AF cameras I own (the F4 and the D1).
> AF reporting is on whenever the light meter is on. Even without any lens
> attached (obviously, in that case the camera reports that it doesn't know
> what to do).

That makes sense. Maybe someone should tell Canon...

David J. Littleboy
Tokyo, Japan
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

"David J. Littleboy" <davidjl.RemoveThis@gol.com> wrote in message
news:dr7tr8$ono$1@nnrp.gol.com...
>
>
> That makes sense. Maybe someone should tell Canon...
>
> David J. Littleboy
> Tokyo, Japan
>
>
I know that was an innocent remark but in seriousness... Have you ever tried
to tell Canon anything? They don't actually have any procedures in place for
customer feedback or a "wishlist" in future products. Like most Japanese
multinationals they think they are the source of the universe.
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

"no... it's not!" <only RemoveThis @the.group> wrote in message
news:kRQBf.226894$V7.4625@news-server.bigpond.net.au...

> I know that was an innocent remark but in seriousness... Have you ever
> tried to tell Canon anything? They don't actually have any procedures in
> place for customer feedback or a "wishlist" in future products. Like most
> Japanese multinationals they think they are the source of the universe.


Having experienced some product co-developement
with Canon, I can tell you -- there's more truth to this
than you can imagine.

Oddly enough, a US-based firm (brand L, shall we say)
showed much more flexibility and willingness to compromise.


rafe b
www.terrapinphoto.com
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

"no... it's not!" <only.TakeThisOut@the.group> wrote in message
news:kRQBf.226894$V7.4625@news-server.bigpond.net.au...
>
> "David J. Littleboy" <davidjl.TakeThisOut@gol.com> wrote in message
> news:dr7tr8$ono$1@nnrp.gol.com...
>>
>>
>> That makes sense. Maybe someone should tell Canon...
>>
>> David J. Littleboy
>> Tokyo, Japan
>>
>>
> I know that was an innocent remark but in seriousness... Have you ever
> tried to tell Canon anything? They don't actually have any procedures in
> place for customer feedback or a "wishlist" in future products. Like most
> Japanese multinationals they think they are the source of the universe.
>
This is true of most corporations....Part of the reason is that they are
afraid that they will have to pay a royalty to someone should they actually
take their suggestion, which might very well be for something that they
already had on their drawing boards anyway........
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

In article <ZN6dnT2i0r2VbkreRVn-og.DeleteThis@comcast.com>, William Graham
<weg9.DeleteThis@comcast.net> writes
>
>
>There is another alternative. If you use a tripod

That isn't an alternative - if you read the post that kicked this
sub-thread off, that was what I was doing!

> and take still subjects,
>you can use shutter speeds slower than one second, and the mirror slap won't
>affect the photograph because it will only shake the camera for a very small
>percentage of the exposure time.
>
Have you any idea what percentage of the total exposure you need to have
that motion damped out in before it becomes invisible. Obviously it
depends on the scene, and in this instance it was stars - quite bright
compared to their black backdrop, so the exposure needs to be very long
indeed if your camera is vibrating on the tripod for half a second after
the shutter opens.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

"Kennedy McEwen" <rkm.TakeThisOut@nospam.demon.co.uk> wrote in message
news:K0yIi5ACRA2DFwl4@kennedym.demon.co.uk...
> In article <ZN6dnT2i0r2VbkreRVn-og.TakeThisOut@comcast.com>, William Graham
> <weg9.TakeThisOut@comcast.net> writes
>>
>>
>>There is another alternative. If you use a tripod
>
> That isn't an alternative - if you read the post that kicked this
> sub-thread off, that was what I was doing!
>
>> and take still subjects,
>>you can use shutter speeds slower than one second, and the mirror slap
>>won't
>>affect the photograph because it will only shake the camera for a very
>>small
>>percentage of the exposure time.
>>
> Have you any idea what percentage of the total exposure you need to have
> that motion damped out in before it becomes invisible. Obviously it
> depends on the scene, and in this instance it was stars - quite bright
> compared to their black backdrop, so the exposure needs to be very long
> indeed if your camera is vibrating on the tripod for half a second after
> the shutter opens.

I don't know, but there have been others who have made such tests, and IIRC,
exposures of more than a second or so were long enough....the mirror slap
dampens out rather quickly......I think that if you are doing that kind of
work, you could ascertain the answer to the problem yourself.....Stars
against a black background are the ideal subject for such a test, and the
answer would probably vary depending on your equipment anyway.
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

In article <De-dnSG6geKtkUXeRVn-pQ.TakeThisOut@comcast.com>, William Graham
<weg9.TakeThisOut@comcast.net> writes
>
>"Kennedy McEwen" <rkm.TakeThisOut@nospam.demon.co.uk> wrote in message
>news:K0yIi5ACRA2DFwl4@kennedym.demon.co.uk...
>> In article <ZN6dnT2i0r2VbkreRVn-og.TakeThisOut@comcast.com>, William Graham
>> <weg9.TakeThisOut@comcast.net> writes
>>>
>>>
>>>There is another alternative. If you use a tripod
>>
>> That isn't an alternative - if you read the post that kicked this
>> sub-thread off, that was what I was doing!
>>
>>> and take still subjects,
>>>you can use shutter speeds slower than one second, and the mirror slap
>>>won't
>>>affect the photograph because it will only shake the camera for a very
>>>small
>>>percentage of the exposure time.
>>>
>> Have you any idea what percentage of the total exposure you need to have
>> that motion damped out in before it becomes invisible. Obviously it
>> depends on the scene, and in this instance it was stars - quite bright
>> compared to their black backdrop, so the exposure needs to be very long
>> indeed if your camera is vibrating on the tripod for half a second after
>> the shutter opens.
>
>I don't know, but there have been others who have made such tests, and IIRC,
>exposures of more than a second or so were long enough....the mirror slap
>dampens out rather quickly......

Well, assuming that your star almost, but doesn't quite, saturate the
ADC with the exposure you eventually make and you have a 12-bit ADC (as
in the Canon 5D). Then your exposure needs to be more than 4000 times
longer than the time it takes for the shutter slap to dampen out to
ensure that nothing from the star registers on the ADC during the time
the camera is moving.

If that takes 1/2 a second to dampen out then you need an exposure of
2000seconds (about half an hour) for the effect to be eliminated. By
that time, the star will certainly have moved in any case unless you
have a mount driven at sidereal time. That's what is required for
complete elimination of the problem - obviously you might tolerate some
remaining, but I hope you can see the magnitude of the problem now.

>I think that if you are doing that kind of
>work, you could ascertain the answer to the problem yourself.

Indeed. I did. It is a problem - hence my original comment - and it
wasn't a problem with the level of shutter/mirror slap on any of the
OM-1/2/3/4, but it sure is on the Canon.
>....Stars
>against a black background are the ideal subject for such a test, and the
>answer would probably vary depending on your equipment anyway.
>
And stars against a black background are just the sort of objects to
show the problem at its worst too.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

"Kennedy McEwen" <rkm.TakeThisOut@nospam.demon.co.uk> wrote in messag

It is a problem - hence my original comment - and it
> wasn't a problem with the level of shutter/mirror slap on any of the
> OM-1/2/3/4, but it sure is on the Canon.
>>....Stars
>>against a black background are the ideal subject for such a test, and the
>>answer would probably vary depending on your equipment anyway.

For half hour exposures, I would just lock up the mirror, so the problem
would go away.....There must be other vibrations to worry about with a motor
driven camera mount that are far more important........
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on... 

In article <4ZydnSzfmKpAzETenZ2dnUVZ_sudnZ2d.RemoveThis@comcast.com>, William
Graham <weg9.RemoveThis@comcast.net> writes
>
>"Kennedy McEwen" <rkm.RemoveThis@nospam.demon.co.uk> wrote in messag
>
>It is a problem - hence my original comment - and it
>> wasn't a problem with the level of shutter/mirror slap on any of the
>> OM-1/2/3/4, but it sure is on the Canon.
>>>....Stars
>>>against a black background are the ideal subject for such a test, and the
>>>answer would probably vary depending on your equipment anyway.
>
>For half hour exposures, I would just lock up the mirror, so the problem
>would go away.....There must be other vibrations to worry about with a motor
>driven camera mount that are far more important........
>
The shots I made were around 15-20s and the mirror *was* locked up, as
already mentioned - at least it was after I saw how bad the problem was
on the preview screen. Even so, it was still there in the final images,
even with the mirror locked up.

The half hour exposure comes from an assessment of what would be
required to eliminate the residual motion caused by the shutter opening
and was provided to show you that your suggestion of long exposure
really isn't practical unless some serious star tracking is used - and,
yes, there are more issues to worry about but, in any decent setup,
vibration from the drive isn't one of them.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's pissed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)
 >> Stay informed about: [K-M - Sony] Damn! Now let's move on...