Shooting wide.
 

Hi guys,

Ok - having a little bit of trouble shooting wide shots in low lux with my current kit.

When the light isn't so high, I shoot with iso up to 1600 (don't like to push it past 800 usually), and obviously keep the shutter speed at 50. But, when that isn't enough, I open up the aperture. This works fine for close shots, but shooting a subject from a distance with apertures from 1.4 - 3.0 (often with a Sigma 30mm prime), my image looks very grainy, inspite of me focusing well on my subject. When the light is high enough, I shoot all wide angles with a much higher aperture (5.0 upwards)

Would love to get some advice on how to compose good wide shots in relatively low light with a 7d or an eos 550 (T2I), and specifically whether it is ever a good idea to shoot wide shots with a very wide aperture.

I'm sure this contains a few misconceptions, any corrections to my understanding welcome and appreciated

Thanks guys,

John

At a 1600 ISO you're going to get some grain. You probably don't see it on closeups because it will shot up more on wider shots where there are dark and/or saturated colors around the subject. What you're focused on has no relation to the graininess, nor does the aperture. That's a function of the ISO. If you're shooting at an f1.4 and at a 1600 ISO, that must be a really dark place. These big chip DSLRs are good in low light, but they're not magic.

Hi Bill,

Thanks for the response - that makes things clearer. So, shooting with a wide aperture has not connection to graininess of the image. Maybe the poor quaity of my wide angel images is due to the majority of the picture being out of focus? Hm.

John

John,
Maybe you are in focus but you also have to remember that wide f stops can expose a lenses flaws more than smaller one. Most lenses look best at a 4-5.6 range. You can decide whether an iso increase is worse than the lens being wide open. My guess is it is better to live with the iso noise in those situations as optic focus most likely ruins the shot more than the noise.

John, you're talking two different things. Grain (video noise) is one, softness is another. The grain is caused by higher ISOs. If you're using a cheap lens and shooting wide open, then you would perhaps get a little bit of softness compared to shooting stopped down. But with a fast lens you would also get a shallow depth of field, so most things in front of and behind your subject would be soft while the subject is sharp. But softness has nothing to do with grain. That Sigma 30 is supposed to be a pretty decent lens.

On the 7D I would start seeing grain at 1200 ISO, and sometimes at 640 depending on the subject. More saturated colors would show it more than others. But the grain wasn't obnoxious. I don't recall ever shooting anything at 1600.

Hi guys,

Thanks for those clarifications. Looking more closely at my images, I think that whilst the ISO noise is there (and that contributes to the poor image) the primary problem is the softness of the focus. I've been using the autofocus on the sigma, but I've spotted some threads that say its inaccurate at times.

I think the missing piece of my kit is something to help me manually focus more accurately, especially in wide shots. So, I'm gonna look at an LCD screen to attach to the accessory mount or maybe one of these

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=320593966970&ssPageName=STRK:MEWAX:IT#ht_3397wt_989

I know this is a cheap version, but cash is tight just now!

Any suggestions very welcome and thanks again!

John

Hi guys,

Thanks for those clarifications. Looking more closely at my images, I think that whilst the ISO noise is there (and that contributes to the poor image) the primary problem is the softness of the focus. I've been using the autofocus on the sigma, but I've spotted some threads that say its inaccurate at times.

I think the missing piece of my kit is something to help me manually focus more accurately, especially in wide shots. So, I'm gonna look at an LCD screen to attach to the accessory mount or maybe one of these

eBay - The UK's Online Marketplace

I know this is a cheap version, but cash is tight just now!

Any suggestions very welcome and thanks again!

John

An essential tool! I couldn't shoot without an LCD viewer. Even with the 5X and 10X magnification button, it's hard to focus without being able to block the light off the LCD screen.

I'd say auto focus, then, is most likely your problem. I've never used it, and in low light on most any lens it's not all that accurate. It's slower than doing it manually too.

Some of the LCD viewers don't have an adjustable diopter,which may or may not be a problem for you. I used the Hoodman, which now has a 3X magnifier in addition to the adjustable diopter. With the 3X magnification, I can often focus without using the camera's 5X of 10X magnification, unless I'm using a wide angle lens.

An LCD viewer is essential, especially since 5x and 10x mag doesn't work once video is started, so you need to be able to adjust focus as necessary.

I never trust the contrast based AF on my 7D, especially with a fast lens like the 30/1.4.

a 3x Zacuto pro finder would be ideal. If shooting off a tripod, a 5 inch or 7 inch monitor would be good. Both of these items are on my priority purchase list.