Tips on adding DoF

[MalakiUK]

Hi, I hope this the right section. Im after advice on how i can better add DoF given the equipment i have. I like to take pics of cars and bikes as a hobby.

 

I have a Canon 450D with the standard18-55 lens and an 18-250m. I was going to attach 2 pics as examples but theyre too big so will add a link. I thought it was going to be a case of zoom in as far as i can and set to the lowest f-. Im self teaching so a bit thick with alot of this. Any help would be great

 

Pic 1 - This i would have liked the van blurred also >.<

Pic 2 - This pic i had the background blurred but not the foreground

Edited September 3, 2023 by MalakiUK

[Ryewolf]

Hi malaki, welcome to forum, regarding image sizes there is a limit to the file size per post.

I think your main problem is not with the lenses themselves, assuming these are both f3.5. The main problem in both images is the foreground and subject are almost on the same focal plane. I'll post a couple of images to show this.

These were both taken at f4, in the first image there is nothing in front of the subject, which is the stone ball, so all the background is blurred.

In this second image a foreground object is some distance in front of the subject, and I used a single focus point so both the foreground and background are blurred but the subject is in focus. Again taken at f4

Judging from the tight spaces you're working with it might not be possible to do much about the DoF

[Fogey]

Hi Maliki, welcome to the forum. 

Regarding your question – DOF; (depth of field) can be achieved in two ways; the first, as you rightly say is by opening the aperture.  The second is to ensure the background is further away.

Let me clarify:  A telephoto lens will have blurring, (bokeh), in front and behind the subject when the lens is set to 300mm/400mm/600mm or whatever. 

When the lens is set to the maximum focal length, opening the aperture will increase the bokeh marginally.

The photographs you have shown, have been taken close to the subject. 
Could I suggest you try using the 250mm lens and stand back from the subject.  When you focus on the subject from a distance, the background will automatically become blurred with the aperture wide open because it is further away from the camera.

Once the shot is taken, zoom in during post processing if you want a close up.  Try to angle the shot so it excludes annoying things like cars, vans and people.

There is a principle called hyper-focal distance, I think you could bone up on.  It’s used in landscape photography to ensure the background is sharp. 

However, if you reverse the same principles, by opening the aperture and using the zoom judiciously, you can get some very pleasing effects with bokeh.

Hope this helps.