Camera Labs

I am wondering and looking for tips on 35mm f/2.4 lens and bokeh achieving.
Since there is no manual focus - the questions that come in my mind are:
1. when i want to blur the background (bokeh) I can keep the aperture wide open and come closer to the subject.
If I had an option of manual focus probably I can vary the amount of blur for the background as desirable but since this lens is autofocus only, how do you achieve the various blur levels on a bokeh portrait?

2. Is there a standard/general aperture reading (numbers) for various scenes to start with for example if I am taking a portrait on manual mode - how do I determine a specific aperture number as a starting point? and then change and tweak it depending on the exposure conditions. So my question is, are there any numbers for different scenes instead of experimenting different numbers for each aperture setting on a scene.

thanks
Sany

Ok, so I think your confused between the aperture and focus. Focus defines the distance away from your lens at which objects are in focus. Aperture defines how tight or narrow this "oobject is in focus" range is.

To achieve a more exazzurated bokeh, you need to have a higher aperture number. As a side note, a larger aperture (lower f number) gives you a faster shutter speed. As always, have you ISO set to as low as you can while still keeping your shutter speed high enough to freeze motion - which is usually desired in portraits.

Now, I find it odd that you say your lens does not have manual focus... Usually if anything, a lens will lack autofocus - not the othe way around. Either way, I always use autofocus because I trust computers more than my eye

To try these ideas out, have a subject around 0.5 m from your lens, with a backround further than 3 m away. open your aperture up as wide as you can and focus on the subject. This will give you the largest bokeh that your lens is capable of. Now, take the picture again but close your aperture a bit (higher f number). You will see that the bokeh effect is reduced.

Hope this helps!

Thanks Trevor again, I have ordered pentax DA35mm f2.4 AL and have just received my K-r camera body. I see that this lens supports only auto focus from the description - this is why i mentioned that manual focus is absent, i now will have to double check this since your news comes as good news for me as i can manually as well play with the lens.

Trevor, sorry about my mentioning of 'manual focus' absence - I checked the review again
'...When the AF is selected on the camera, the focusing ring does not allow for any manual adjustments. Any manual focusing must be done with the camera's focusing selection placed on manual.'

It is only when AF is selected from the body that the manual focus is not available but Quick shift is also absence.

So you are right! apologies for the confusion.

Any idea about the aperture settings for a starter like me!? For example, say i am a newby and landing in a new outdoor and want to shoot with manual setting. Where or rather how do I get the number (initial number to start with) for the aperture. Is there any standards that we need to stick to as a thumb rule from where we can go plus of minus that value to achieve our right exposure or is it only achieved by experience?

thanks

Well, for most applications you would go as big as you feel comfortable with. My maximum aperture is f/2.8, but I loose sharpness with my lens (relatively low quality) at this, so I only used it when I need an exaggerated bokeh, or in tough lighting conditions. I would typically shoot at f/4 to freeze motion. In circumstances where you want long shutter speeds, then you start to close your aperture. But these are more of and advanced type of photography which, within a month or so, I suspect you'll start to play with.

I will typically use aperture priority mode in my camera, and sometimes fully manuel. Check your camera manuel to see how to switch between the two. Think of aperture priority as semi-autmoatic. You set your aperture and ISO (again, as per my previous post, ISO should be as low as you can afford to go), and then your camera automatically chooses a shutter speed to give you a balanced exposure. There are some things that influence the cameras decision on the shutter speed - things like metering and exposure compensation... but you'll lean about that in due time.

Now, in fully manuel mode, you choose your ISO, aperture, and shutter speed. This will take a little bit of playing around with to know what to use, but it doesn't take long to get the hang of it.

Hope this helps!

Thanks Trevor it was very useful and also encouraging for a newbie.
Will get back for more tips as required.

There's the DSLR-tips website also!

http://www.cameralabs.com/features/Latest_Features_and_Workshops.shtml

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Ruben

Panasonic DMC-FZ18, Panasonic DMC-FZ28, Canon G5, Canon 350D, Canon 50D + BG-E2N
Tamron 17-50 2.8, Canon EF 70-200mm f/4L USM,
Canon 18-55 II plus lots of Minolta MD/M42 lenses and bodies