QUESTION: Small vs wide aperture shots in low light

Hi, all.

I'm headed to Carlsbad, New Mexico next weekend, to wander through the
Caverns for a couple of days. I have been there once before. The light
in there was pretty low, overall. I'd compare the lighting with a
sporadically lit street in the middle of the night: there are
spotlights illuminating the attractions, and a lot of darker areas
between.

When I went last year, I had a Nikon Coolpix 4500 with the stock
speedlight. Results were pretty marginal overall. That camera did not
write in RAW either, which in hindsight cost me quite a bit in the
ability to post-process.

Now I'm going with a 6MP Canon Rebel, a 17-85IS, a 75-300IS, a 50mm
f/1.4, and a Sigma 150mm f/2.8 Macro, which I will be getting my hands
on when I get into the State. I also have a Canon EX550 flash. I feel
fairly well-armed for the trip. No L lenses, but what can I say.

I'm expecting that with the better low-light behavior of the Rebel, and
with the maximum aperture of the 50mm and 150mm lenses, I should be
able to capture some excellent low-light shots.

I intend to try some shots at the maximum aperture of my two prime
lenses, and also some tighter aperture settings, with a flash if
required. I really don't want to go past ISO100, because I want the
richest possible results.

Aside from the depth-of-field differences, what other kinds of
differences should I expect between wide-open shots and shots of, say,
f/16 or higher? Is the clarity necessarily better?

BTW - I will be armed with a tripod and a remote.

Any general technique-related suggestions for a shot in a lower-light
environment? All suggestions I can glean before I go would be greatly
appreciated. - Oh - I will be shooting everything in RAW.

I guess I should figure out how to use the mirror delay in my camera,
for one thing. ;-)

Thanks!!

BD

 

Why digital?

Digital sensors don't accummulate light like film....

 

f/16 will likely not be the sharpest setting, more likely around f/8,
this depends on the lens.
I have not used the 50mm 1.4 lens but I know the 50mm 1.8 gets way
sharper if you can shoot at f 2.8.

Don't know about the Rebal but the mirror delay on the 20D is a snap to
use and for long exposures can make a big differance.

So go in a dark room in your house and try all this out now while it
does not matter, you will find out what works and what does not.

Scott

 

Which is why most of us no longer use film.

Scott

 

I would personaly shoot most everything tripod, remote release , low
asa, mid to smaller lens opening usualy is where the lens is sharpest
depending on lens, and use a Circular Polariser and a Tiffen Enhancing
filter even both together. With poor light, good scenes tripod- remote
trigger is best anyway, Im going from analog A1- K25 experiance.

 

Carlsbad caverns, oh, thats inside so forget about the filters, I was
thinking an outside location, a long day is been.

 

OBVIOUSLY you've never used a digital SLR

 

So go in a dark room in your house and try all this out now while it

Makes sense. Emulate the conditions and experiment.

If I only had a room in my house the size of 2 football fields, I'd be
able to approximate even better!

 

It's been a long time since I've seen any reminders of that
useless troll. Better to starve the beast than feed him with your
attention, his favorite meal.

 

forget about the filters

Good - 'cause I don't have a Tiffen Enhancing filter anyway. ;-)

 

Foget the flash in the caves. It will only flatten the scene and wash out
the details.
You're better off using available light.
Tripod, ISO 100, and 30 seconds to a minute, depending on aperture.
Shoot RAW, and you'll be MUCH more able to effectively deal with the weird
mixture of lighting types they have in there.

Here's a shot I took there last year:

http://www.pbase.com/markuson/image/37442910/original

-Mark

 

Quite so - accumulation of light on film is plagued by reciprocity failure.
It's simply not an issue with digital though. 1 hour exposures with no
adjustments needed for reciprocity failure - nice.

I can take star trail pics with a DSLR using settings that leave a sheet of
film pretty much completely black.

 

Unless, of course, you leave the camera on tripod, shutter open, and
walk around here and there popping a flash to create depth and
dimension. Oh yeah, I forgot...that requires a flash that isn't built
in and people seem to have forgotten that such exist let alone how to
use one.

--
dadiOH
____________________________

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Get it at http://mysite.verizon.net/xico

 

I was going to suggest that but you beat me to it. Here in Idaho, we have
the Craters of the moon N.P. which is blessed with a number of caves, some
just dark and some lightless. We set up the camera on a tripod how we want,
stop down to f 16 open the shutter and lock it and holding the flash in my
hand, I paint with the flash. I do experment with diffusers over the flash,
I even put some wax paper over the flash to really diffuse the light on some
shots. Try to go when there is fewer crowds.

F1

 

Tripod, ISO 100, and 30 seconds to a minute, depending on aperture.

I guess that would work.

My main concern about long exposures is the 'big room' at carlsbad -
you know, the one that's 2 football fields long. If I go for several
seconds in there, I'll have people milling about in the distance during
the exposure. It could make for some labor-intensive cleanup after the
fact.

But if you feel that the results would benefit, I'll certainly give it
a go.

I agree with shooting RAW. That's the plan.

Thanks for the tip on the long exposures; I honestly hadn't expected to
do that, but had planned to rely on wide apertures.

 

Unless, of course, you leave the camera on tripod, shutter open, and

Can you clarify this for me?

Are you saying that I should (for example) set up a long exposure, take
my external flash in hand and just fire off the flash manually in the
scene during exposure, pointing it where I like? I've never heard of
that. Sounds interesting, though. Maybe I should bring a patch of white
fabric to act as a diffuser for the flash as well...?

 

If you leave the shutter open for several seconds, the people milling
about will blur out. If not, they could add perspective to the size of
the room.

 

If you leave the shutter open for several seconds, the people milling

True. I like the idea of adding richness with the long exposure, but
don't want all the smears of passersby. I'll probably do a
long-exposure shot, a quick wide-aperture shot, and then do some
creative cloning in PS afterwards to erase the pedestrians or leave a
few in to illustrate scale.

 

"Painting" with a flash would be creative. Are you sure they allow
flashes to be discharged, probably not as it would blind others, unless
you can get permission, perhaps a different time.You could spend a day
easily being creative with lights, even handheld flood.

 

I was about to suggest that. Try to stay out of the picture (behind
the film plane); if you can't, wherever you go, there you are...