Re: 5 Digital Camera Questions

From: Tom Ferguson ^lt;[email protected]>
Date: 06/11/04-08:54:27 AM Z
Message-id: <>

On Thursday, June 10, 2004, at 09:44 PM, Judy Seigel wrote:

> <SNIP>
> My reason for choosing 5.6 was so the figure would be in focus and the
> background be softer, which this project calls for. There's a
> "portrait"
> mode, which apparently does something similar. With this kind of quick
> street shooting, my best bet is probably to change to "auto" in sun
> (changing the menu is a very long song & dance) & of course everything
> will be tack sharp. If I can't stay out of the sun, I'll have to
> "fix" it
> in Photoshop. (There are also a couple of neutral density filter
> settings.
> Now I can see why !)

You are thinking like a 35mm film photographer!

F/5.6 on a consumer digital has a LOT of DOF. I'm not sure if all of
the consumer dig cameras have exactly the same sized sensor (I think
they do), so I'll use my Sony F707 as an example. The sensor (film
area) in these little jewels is TINY (about 7x5mm, about 1/4 inch).
That makes the lenses needed very wide. Often the manufacturers label
them in "35mm equivalents", but in truth your G5 lens is a 7-29mm zoom.
All of that makes for a huge DOF.

Think of film cameras. No-one, but the pinhole crowd, would think of
using F/64 on a 35mm Nikon. But the 4x5 crowd loves F/64, and the 16x20
film camera crowd (well, that is a small group, not a crowd) wants
F/128. As film gets larger you get less DOF and need smaller f-stops.
As film (or sensors) get smaller you get more DOF and need wider
f-stops. With consumer digital you have gone beyond small and reached

With my F707 (and I think it is identical in this regards to your G5) I
have 3.9 stops DOF difference (call it 4 stops). That means your F/5.6
on your G5 has the same DOF (for the same pic taken from the same spot
with a 35mm film camera) as F/22. Try it, it is true. Or see here:

All of the above is true for CONSUMER digital cameras. It is not the
same for DSLR cameras (D70, D100, S2,14N,10D). The DSLR camera have
either exact same DOF (FF sensors) as a 35mm film camera or just
slightly more DOF (APS sensors).

>> Most (all?) of these wonder batteries slowly wear out. Nothing to do
>> but buy a new one (if that is the case). Flash use, and the rear LCD
>> use a LOT more battery power than the EVF viewfinder. I would guess I
> Actually, this happened with the first charge, and again with the
> second... The manual says it charges 300 times. I bought a spare 3rd
> party
> battery -- nothing said about how many charges it would take, now that
> you
> mention it...
>> get 200 shots if using EVF and no flash (and my batteries are getting
>> old). Limited experience guesstimate, after 500 charge and discharge
>> cycles, it wouldn't be surprising to lose 1/2 of my battery capacity.
> What brand of battery does 500 cycles? (As noted I'm getting about
> 1/7th
> claimed capacity with a brand NEW battery.)

If you are only getting 60 images without flash from a new Canon
battery, then I strongly suspect you have a bad battery or something in
your camera is drawing too much power (short circuit). That is not
normal in the general consumer digital world. In fact I just checked my
beloved and the review there list the G5 as having "Superb
battery life".

Third party batteries can be every bit as good as the originals, or
terrible. But the fact that both your original and third party battery
are acting the same make me worry about your camera. One limit to our
alt photo group is there may not be another G5 user here. Try asking at
the DPreview Canon group:

My "guesstimate" of 500 charges was based on a guess (uncounted) of the
number of times I've recharged my Sony batteries. They are now about
1/2 as strong (long lasting) as when I started. I certainly could be
WAY off in my mental count.

> <SNIP>

Remember that shooting Jpgs is like shooting slide film. Your exposure
needs to be ^$%# close to perfect. For "street shooting" you may want
to play with shooting RAW. Much more like shooting neg film (room for
error). It does take a lot more memory space, and requires computer
time to convert.

Your camera can be set to 50, which DPreview says is closer to ISO 80.
That would give you the possibility of using F/4 at 1/1250 in full sun.
I think your camera will reach that speed at all lens settings. That
would give you the same DOF as a F/16 on a 35mm film camera. That will
give you a "slightly" more blurred background and far less chance of
blown-out images. About the best you can do with a G5, without using
density filters!

Tom Ferguson
Received on Fri Jun 11 08:56:11 2004

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