4 Jul
2011
4 Jul
'11
3:15 p.m.
the "close up" is in fact reversed, no I dont have any extensions or
tubes for the Canon 300D
a look on ebay says none in the country, besides no current job so Im
tight and dont spend money
I would prefer a higher resolution camera with live view on the linux box,
the canon is a true reflex with a mirror so makes it difficult to use
in this application
I would like to know if something like an Olympus X-42 can have a live
view so it makes the usage a lot easier
I can then preview the image before grab
Dave Caroline
On Mon, Jul 4, 2011 at 10:53 PM, Pete Turnbull <pete at dunnington.plus.com> wrote:
On 04/07/2011 20:20, Dave Caroline wrote:
Tony Im just in the pocess of jury rigging a better close up experiment
http://www.collection.archivist.info/archive/fiche_experiments/50mm_canon_l…
was yesterdays experiment, some exposure error hence noise and also
thats hand held
next is to bolt stuff to a stand so I can increase exposure time and
reduce shake at the same time
I think I need a higher resolution sensor in the camera though
I don't think you need higher resolution, just more magnification.
> Can you use 'traditional' closeup
methods (extension tubes, bellows, etc)
> with digital SLR cameras? If so, that's what I would be looking at using.
To answer Tony's question, in general, yes of course you can use rings,
bellows, and all the other things with digital SLRs. ?I suspect he knew
that, maybe he was asking if Dave has access to those things.
Dave, can you get hold of a set of extension rings? ?or a bellows unit?
?That'll get you better magnification. ?And use a shorter focal length with
tubes or bellows; that increases the magnification. ?A good trick if you can
do it is to turn the lens round. ?Firstly that's because camera lenses are
optimised for a short distance between lens and film/sensor and a longer
distance between lens and subject; here the situation is reversed so the
lens will usually work better back to front. ?Secondly, you can often get
the lens closer to the subject when it's reversed, especially with a
retrofocus lens (ie a "wide angle" lens). ?Don't try to focus by turning
the
focussing ring (or moving the bellows in and out if you have one); you've
possibly already discovered it's easier to set the magnification and then
move the whole unit back and forth to get the focus. ?Ideally, stop the lens
down about halfway or just a bit more; that's when most lenses are at their
sharpest.
--
Pete ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Peter Turnbull
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Network Manager
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?University of York