Go Back   Steve's Digicams Forums >

LinkBack Thread Tools Search this Thread
Old Jul 7, 2005, 1:50 AM   #1
Frangible's Avatar
Join Date: Jun 2005
Posts: 59

To investigate the effects of exposure time on blur in the DSC-T7 I performed a small test at varying shutter speeds.

All the shots were taken by an unsupported (ie: handheld) T7.

No postprocessing was done other than the crop.

ISO64, 1/2 sec. No flash. Two flourescent lights on.

ISO100, 1/4 sec. No flash. Two flourescent lights on.

ISO200, 1/8 sec. No flash. Two flourescent lights on.

ISO400, 1/15 sec. No flash. Two flourescent lights on.

ISO400, 1/30 sec. No flash. Three flourescent lights on.

ISO400, 1/40 sec. Flash used. Three flourescent lights on.

In conclusion, I feel 1/40th of a second is the minimum shutter speed for me to take unsupported non-blurry pictures while having minor hand trembling from caffeine.

I also found the best way to hold the T7 is with both hands forming a "V" and touching at the ball below the thumb, while resting the elbows on the torso.
Frangible is offline   Reply With Quote
Sponsored Links
Old Jul 7, 2005, 7:18 AM   #2
Junior Member
zack33's Avatar
Join Date: Jul 2005
Posts: 6

Thanks for the tips

(0) What Is 'Exposure Time' can it be set maunally on T7, will that give me Blur free photos Indoors/outdoors, without flash

(1) how do you manually set the T7 to 1/40 sec, so that i get less blur free (NOT USING FLASH) INDOORS/OUTDOORS

(2) on your last photo 'iso 400 , 1/40 sec'..if you set it to' iso 64, 1/40' would there be blur,(IF NOT USING FLASH)also are you using the x3 optcal zoom for the tests, if are would you encounter more/less blur with these tests

(3) So i'm still a newbie at photography..'The Higher The second number"1/Number the less blur...can you set the T7 to 1/500 sec

(3) I don't know if this is a silly question, but its the only way to learn LOL

What results would you get if you had a Camera with (NO FLASH USED):-

1/1 sec

1/4000 sec

2/1 sec

2/4000 sec

can You recommend a small DC thats good for photos

zack33 is offline   Reply With Quote
Old Jul 7, 2005, 7:34 AM   #3
Senior Member
Meryl Arbing's Avatar
Join Date: Jan 2003
Posts: 436

It is hard to tell from handheld shots since there are so many variables that contribute to camera shake. This just goes to prove the old saying that 'Cameras don't take blurry pictures; people take blurry pictures!"

1) The 1/40th of a second isn't any magic number, it is just the flash sync speed of the camera when the flash is used. In this case, it is the flash that freezes the action and suppresses camera shake and the flash duration is much...MUCH shorter than 1/40th of a second.

2) As you reduce ISO, the image just gets darker (with the same shutter speed) but the degree of blur would remain about the same.

3) Yes, 1/1000th of a second is ten times faster than 1/100th of a second and more able to freeze motion (including camera shake that causes blur)

Also, the more you zoom, the more camera movement is exaggerated.Tiny hand movement is magnified when you use the zoom. In the film world, the rule of thumb was that, in order to hand hold a telephoto shot, you needed to have a shutter speed which is the reciprocal of your focal length. So if you have a 250mm lens, you need to have a shutter speed of 1/250th (or FASTER) to minimize camera shake. The heavier the camera the more difficult that was. In any case, if you can't get that sort of shutter speed then the only solution is to brace the camera agsinst something or to use a tripod.

One of my suggestions for digital camera users is NEVER to use the LCD to take pictures because you have to assume the most unstable and shaky position (arms outstretched, head tilted, back arched, feet spread) that it is no wonder that pictures are blurry. Use the LCD for review (AFTER the shooting day is over) but not for taking. Unfortunately, camera manufacturers are making it difficult to avoid using the LCD by either not including an optical viewfinder at all OR making the optical viewfinder so primitive as to be useless.

Meryl Arbing is offline   Reply With Quote
Old Jul 7, 2005, 10:06 AM   #4
Frangible's Avatar
Join Date: Jun 2005
Posts: 59

You cannot specifically set the exposure time on the T7. I induced all of the changes through changing the ISO or the lighting. Manually set the camera to ISO400 for the shortest exposure time (but note the noise increase as a result).
Frangible is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 11:25 PM.