Model Forum / General / Railroads / November 2007

Dave (and others),

That's a good question... to be honest, I've never tried it.  This is just a
guess but I would guess that it would eliminate the lag time for the camera
to focus.  Like I said, that is just a guess though.

dlm

Good morning David;

   It does once the lens is in focus and the distance remains relatively
constant.  Otherwise, the autofocus on my camera is faster than me.  One
thing about the auto-focus is it can be set up several ways.  If shooting
moving objects, I'd recommend a spot focus.  I purchased the same type of
kit as Dan and I find it a good camera although I would have preferred
Canon's Rebel XT which was twice the price.

Cheers,
John

Interesting.  Even the HD TVs that are becoming so popular nowadays have
images in only the 2.0 MP range.

And your analogy to the computer monitor is a point well taken.  However,
with my bad eyesight, I tend to run in the older 800x600 mode.  Anyone using
my monitor complains about how blurry & fuzzy the images on it are.  So
There s more than one variable at play here.

Perhaps the best display of the whole resolution thing I saw was at our
local Sears store.  There was an album with the same picture displayed in
the same size but with different resolutions.  In other words, the pictures
were all 8x10 but they varied from a pretty low 72dpi up to a much higher
resolution.  I don't remember what the high end was but it was pretty
obvious that with each picture, the image got progressively sharper.  But I
would think that at some point, there would be a dimenishing return on the
increased image size.

For close-up model photography, things like depth of field, a good flash and
a solid tripod might be of equal or greater importance in getting a really
good picture.

dlm

    That is only part of it as well. The point where "more MP"
   is silly is when you have more MP than your lens is able to
   resolve.

    Most quality 35mm lenses can resolve somewhere around 200 lines/
   mm. So, it would make sense that you do not need more than 200 pixels
   per mm on your CCD, either.

    Given the CCD's in use today, that is somewhere around 10 - 12
   MP.

    If you are going to shoot photos for a web site, then you do
   not need a lot of MP, certainly.

    If you are going to make enlargements, or want to enlarge just
   a portion of the image, then it is helpful to have the additional
   resolution.

    What is of most interest to me is the maximum frames/second
   that I can shoot. Most 35mm "pro" level film cameras could do
   5 - 6 frames/second, which means you could go through a roll of
   36 exposure film in 6 - 7 seconds. That got expensive...

    Digital SLR cameras are now at that level today, for around
   $1500.00, body only. And up, of course. Now, sustaining that kind
   of speed is still problematic. Most DSLR's only deliver that kind
   of frames/second using JPEG images, which is an inheritantly
   "lossy" format. So, if you want to shoot for enlargements or to
   enlarge just a section of the image, you are back to losing data
   before you can start working with it...

    You can shoot RAW, which basically takes the sensor data and
   shoves it into a quasi-standard (each camera maker has a different
   idea of how their RAW images are formatted to storage, but they
   more or less follow the same principals. Sorta. Basically). However,
   you are moving a lot more data to storage, and eventually, you
   will fill your storage buffer, and have to stop shooting at a
   high frame rate. The key for me is how quickly that storage buffer
   is cleared. Newer cameras can write the data faster, but there are
   still hardware limitations.

    As for how long does it take an AF camera to focus, that depends
   on the camera. Most DSLR cameras today have some kind of predictive
   AF mode, which calculates where a subject will be when the shutter
   is released. This technology was first marketed by Minolta, who sold
   their camera technology to Sony. Point & shoot cameras, you probably
   have no such luck. You also need to consider how long it takes a
   camera to "wake up" from a power conserving mode. Again, newer DSLR
   are going to tend to be faster than their older counterparts. Nothing
   like missing a shot because the camera was fondling itself...

    As for myself, I shoot Minolta (now Sony) DSLR's. I moved from
   Minolta MF bodies to the 2nd gen. AF body when Canon was thrashing
   around trying to get an AF camera to work even half way well, and
   Nikon was still thinking that AF was a passing fad. When it came to
   digital, however, Minolta was asleep at the wheel. Their first DSLR
   was a frankenstein of a mid-grade consumer AF body with an electronics
   package grafted (ungracefully) to the AF body. But, at 1.75 MP, it
   was fine for photos on a web site, and it preserved my $$$$ AF lens
   collection. Minolta eventually re-entered the DSLR market with a
   poor effort, and exited the photography business completely, which
   is where Sony comes in. Sony recently introduced a DSLR body that
   lives up to the Minolta AF legacy, and is what Minolta should have
   done before they took their ball and went home. In the meanwhile,
   of course, Canon and Nikon ate Minolta's lunch in terms of market
   share.

                                Bruce

Dye-sub printers do wonders for photos, too.

Agreed, and that's my point - if you want performance on a budget - it
can be found IF you know what to look for.  Sorry to hear about the
problem with your Z1 - I guess I've been lucky - it has been *well* used
for many years (having had several Minolta film cameras and as tough as
they are - I've not been all that gentle with the Z1...

I know they were - I wasn't sure they still are (for cameras as old as
the Z1). It's getting harder and harder to find parts for my XD-11
(anyone have an extra take-up spool?) - much less my SRT-101 (batteries)
(grin!)...

best regards...

    Minolta (Konica-Minolta) is NOT owned by Sony. When K-M made
   the decision to bail, the camera technology was transferred to
   Sony. Konica-Minolta continues to exist, and has focused on copiers
   etc.

    Dead? Sony has released two digital SLRs based on the Minolta
   technology, the Alpha 100 (aka "alpha") and the Alpha 700 (aka
   a700). These cameras are fully compatible with Minolta 'A' mount
   lenses (note that some early unlicensed third party lenses will
   not work) and Sony has been working on some new lenses for the
   alpha line.

    There are Minolta MC/MD to A mount adaptors available.
   There will be some tradeoffs, but I can not tell you what they
   will be, as I sold all of my MD equipment to move to the 8000i
   when it was released.

    Soligar made one, but it would be best to do some research
   to find out what is/is not available, and what limitations may
   exist. The VFC may offer some challenges, if it changes the
   rear element position.

                            Bruce