best slow speeds on compact

[geoffbristol]

New here - hello all.

I know a thing or two about film and digital photo processing - but having mostly scanned my own slide film and 'heavily stretched' the capabilites of an Olypus 1.3 mp old camedia, I've at least got myself something I have some control over and has a few more mp's to play with.( canon A620 - cheap too )

In general, shooting with a digital compact of this type ( 7 mp, 1/1.8" sensor) would one expect better results with an iso of 50, say at 1/2 sec ( on a tripod of course) than 100 iso at 1/4 sec ? Given that the subject is static and no flash, in available light of about 6-7 EV.

Is it best to avoid if possible speeds as slow as 1/2 or 1/4 with these sensors, even at 50 iso - ie provide more light - or open up more.
At what slow speeds does noise creep in ?
I'm generally shooting working progress in my workshop ( violins ) and direct flash is not usually good and to rig up lighting is too much fuss, 'on the hop' as it were.

I realise a dslr would suit me better - but this well featured little camera will suit my compact needs, even if I do go bigger eventually. It mostly for high quality web stuff anyway rather than printing at any size.

Geoff - Bristol

[El_Sid]

By and large it's generally better to use the base ISO of the sensor. With most cameras this is normally the lowest available but some do offer special settings below this usually called something like Lo. Looking at the specs of the A620 it looks like 50 is the base ISO.

...would one expect better results with an iso of 50, say at 1/2 sec ( on a tripod of course) than 100 iso at 1/4 sec ?

At web size you probably won't see much real difference but as you will need a tripod for either option I'd go with ISO 50.

Is it best to avoid if possible speeds as slow as 1/2 or 1/4 with these sensors, even at 50 iso - ie provide more light - or open up more.
At what slow speeds does noise creep in ?

I've taken pictures with my Panasonic FX-30 (a similar sort of sensor spec) in night scene mode where the the exposure ran into seconds without seeing an objectionable amount of noise. IIRC the FX-30, and probably the same applies to the Canon, in night mode takes a second dark exposure and subtracts any noise generated by the sensor warming up from the true image.

Even with the small sensors of compacts I doubt there will be much liklihood of heat noise being generated with quarter or half second exposures.

[geoffbristol]

Thanks El Sid
Sounds ok - I've read a fair bit lately on small sensors, but couln't really find anything specific as to 'how slow' mattered. Its been very educational to say the least. I look in a very different light now on some 'high pixel' compact offerings.

I must admit this little camera is a gem now I've played with it a bit - hard to fault really. Should do me for a generally p&s and do the small amont of technical stuff. I like the way the flip screen image turns to vertical when I have it on the tripod in portrait.
SD rather than SDhc is a small drawback. Grabbed a few while they are cheap still !