Different Aperture Test Out

[sunboi80]

I just did a small experiment... just wondering if it's good to share...
As wat Francis mentioned, dun't use high ISO but i figure out that the aperture does play a part also...(correct me if i am wrong) at least for my case... anyway here are some pics to illustrate..hope it helps...

F8 ISO100


F11 ISO100


F22 ISO100


F22 ISO1600


F8 ISO800


I think the results are quite clear... I tried for many settings but CS only allow 5 images per post so post the most dramatic ones...
I realised for my lens, the optimum setting is f8-f11 ISO100...
I guess we gotta experiment to find out our optimum settings and like wat francis mentioned understand our camera and lens better...

[Francis247]

Hi Sunboi80,

I have moved your post and started a new thread for you to discuss.

I realise that you are shooting in Aperture mode which means you control the aperture and let the metering of your camera decide the shutter speed (or exposure time) since you are fixing the ISO setting too.

Do note that the tricky night situation with mixed lighting condition can easily fool your metering. My suggestion is to take full control of your camera and shoot in Manual Mode.

Based on your picture, I gauge that a reasonable exposure is ISO100, f22 and Bulb Mode with 1 minute exposure. As to why your pictures are not sharp, where are you focusing at? Did you try to adjust the focusing manually to infinity, can the tripod take the weight of the set-up? Did you use a cable release? Are there other sources of vibration that might have shake the camera?

(I realise that your the images ISO800,f8 and ISO100,f8 are the same picture. I check the EXIF and found it to be ISO800, f8. Tried editing the link but image couldn't be found.)

[Legoz]

On a side note, i know where u stay. hahha...

F11 looks sweet.
22 is very bad. whats ur shutter speed for the f22?

[sunboi80]

Something seems to be wrong with PB...here's the right file..

ISO100 F8


For my simple experiment, actually i just wan to find out the effects of Aperture and ISO on pic quality so i never change anything... I did not focus on anything hehe, i trigger the shutter with my remote that's all. Anyway i notice that the blur affects not just 1 subject but the whole picture.

Quote: On a side note, i know where u stay. hahha...

wah legoz, u sure? alot of HDB looks the same le unless u staying in same area as me... hehe

[Francis247]

When the aperture become small, the exposure time increase. You need to open the shutter long which means more prone to vibration.

Like I mentioned, can the tripod set-up take the weight? Have you tried manual focusing and focus to infinity? A lot of factors and precautions should be taken into consideration to reduce vibration. Hope that helps.

[Legoz]

Hey, thats near blk 25 rite?
I was just there yesterday morning to take some early morning shots.



Shot this near your block yesterday. =)

[sunboi80]

woo hoo u are right man... hehe
ur pic too dark i can't make out where u shot the pic frm haha

[Octarine]

Originally Posted by sunboi80 For my simple experiment, actually i just wan to find out the effects of Aperture and ISO on pic quality so i never change anything... I did not focus on anything hehe, i trigger the shutter with my remote that's all. Anyway i notice that the blur affects not just 1 subject but the whole picture.

The question about focus refers to the focus point of the camera. Which of the focus points in viewfinder was highlighted? If the camera uses the focus point at '6 o'clock' then the objects at about '12 o'clock' can be blur because they are out of focus. Depth of field in the picture depends on focal length, aperture settings and focus point.

What exactly do you mean with "picture quality"? Noise? Sharpness? Depth of field? First define this detail, then you can adjust your setup to find out the optimum setting for this particular parameter. Here you changed already 2 parameters: ISO speed and aperture. For any experimental setup you should follow the rule: keep everything constant, change one parameter, watch the target parameter / result. So if you refer to picture noise as quality parameter then you should stay in Aperture-Mode, chose one f-stop (let's say 5.6 or 8 - at least 2 stops below maximum aperture of your lens), only change the ISO speed and watch the results. (The camera will adjust the shutter speed, but that's ok since this will keep the exposure at constant level.)
If you want to find out more about aperture settings and how this affects picture quality (sharpness, depth of field) I suggest using daylight to get a more detailed and brighter picture. You can also check at various lens review sites in Internet how they test picture quality in dependency of aperture settings.

[sunboi80]

Originally Posted by Octarine The question about focus refers to the focus point of the camera. Which of the focus points in viewfinder was highlighted? If the camera uses the focus point at '6 o'clock' then the objects at about '12 o'clock' can be blur because they are out of focus. Depth of field in the picture depends on focal length, aperture settings and focus point. What exactly do you mean with "picture quality"? Noise? Sharpness? Depth of field? First define this detail, then you can adjust your setup to find out the optimum setting for this particular parameter. Here you changed already 2 parameters: ISO speed and aperture. For any experimental setup you should follow the rule: keep everything constant, change one parameter, watch the target parameter / result. So if you refer to picture noise as quality parameter then you should stay in Aperture-Mode, chose one f-stop (let's say 5.6 or 8 - at least 2 stops below maximum aperture of your lens), only change the ISO speed and watch the results. (The camera will adjust the shutter speed, but that's ok since this will keep the exposure at constant level.) If you want to find out more about aperture settings and how this affects picture quality (sharpness, depth of field) I suggest using daylight to get a more detailed and brighter picture. You can also check at various lens review sites in Internet how they test picture quality in dependency of aperture settings.

actually i tested using just ISO100 with all the apertures from f4.5 to f22 but 1 post can only post 5 pics and i dun wan to overwhelm the post so i just pick the most dramatic ones... After that then i adj the ISO to see it's effect on the best pic (sharpness).