Photography Lesson – No 2 – Aperture Priority – Depth of Field – Portrait
There might be a slight mish mash of classes coming up on here, because I am having to combine private lessons which a friend and I had with our now college tutor, due to the fact the photography classes last term were cancelled. So we snuck in a few privately last term and now have managed to join the college for the certified course that we originally wanted to join. The homework isn’t quite corresponding however with my other classes, so bear with if there are a couple of repeats please.
This time we are working with the camera on setting A, which is Aperture Priority. That relates to Depth of Field.
What is Depth of Field?
Depth of Field is the distance between the nearest and the furthest objects giving a focused image.
When you turn on your camera, it is the F value on the screen that relates to your Depth of Field. I found out also that your lens shows the minimum range DOF that that particular lens will give. You can see it on the small print where the lens is nearest to the camera when attached. Mine says 3.5-5.6 on my 18-55m lens.
The way to change the aperture setting when using aperture priority (A) is by simply turning the wheel (excuse me if using the wrong terminology) at the back of your camera left or right. Swivelling it right will make the number higher, left smaller and you will see this change on the screen.
The smaller the number equals shallower depth of field.
So for example if my zoom is on 55 and I use a 5.6 aperture setting the item I am focusing on will be more blurred with a shallower DOF than if I use a 14 aperture setting.
To get the best result you zoom in (telephoto) and use the smallest number possible. You will see a red dot (or you should do) on your screen when you are going to focus. You aim the red dot on the area you want clear. Using telephoto with the smallest aperture setting will give you the smallest clear area with the most blurry shallow depth of field in the background.
Though I say smaller number, the smaller the number ie 5.6 = a bigger hole, and higher aperture setting = small hole in the lens when taking the photo.
Nifty bit of info: I didn’t realize but if you take a good look at the back of your lens it will give you the shortest measurement you can take photos with before it won’t focus any more, mine is 25cm with this particular lens.
Another tip given to me was do not remove the lens when it is windy or dirty as hellish or nigh on impossible to clean yourself properly if bits fly inside the mechanism.
Changing the aperture setting will also change the shutter speed which then in turn effects the light intake.
On my camera, the shutter speed is seen on the back of the camera display screen on the left. It is indicated by the ” sign
The shutter speed can look like 10″ which is 10 seconds, or 1/1.6 which is one sixteenth of a second. (gosh I hope I got this all right!)
- Lower aperture setting ie 5.6 = bigger hole = lower shutter speed
- Higher aperture setting ie 14 = smaller hole = slower shutter speed (which for me results in camera shake ack)
I have a little mish mash of homework. Some from our private class and some from this college class.
- Take some portrait photos achieving a clear close up with as blurry a background as possible.
- Photograph various objects and change the aperture setting.
So here we go for my shots!
My first willing victim. I kept my ISO at 100 for all the portrait shots. The distance is the same for the first two at 24mm, however the aperture priority setting (f rating) as you can see is different. This one at 8.
Same settings with the one below but aperture priority setting at 3.8 instead of 8. Notice the difference?
The background in the first one much clearer. Changing the f setting as you can see has also changed the shutter speed on both, the top one from 1/13 sec to 1/25 sec.
Then we zoom in as I was wondering why I couldn’t get that really good blurry background. Of course if I had looked back on my notes I would have realised why. Zoom in, low f value. So here we have 46mm, f value of 5.3 and the ss (shutter speed) of 1/20 sec. Not too different ss wise, but obviously with the change of distance gives a dramatically different photograph. I like this one. I was ‘trying’ to get a slightly more ‘arty’ look with a bit of foilage infront and was wondering how the ‘blur’ would turn out. I was pleased that both the front foliage and background both turned out blurry, thumbs up!
I am actually working backwards on this, as the portraits above were done after the ones below, but heck that’s the kind of thing I do posting backwards.
So here we are at 20mm, working again with an ISO of 100. I used a f value of 3.5 but like above wasn’t getting the background ‘blur’ that I desired.
I will admit also that there were quite a few blurry shots in both instances during practice. Too much coffee perhaps?
So then I moved in. 32mm this time, f/4.5 giving a slower shutter speed of 1/8. Slightly better blur in the background though I felt the photograph a touch dark.
So I moved in for the kill this time. 32mm. A f value of 4.5 which gave me 1/8 sec and a much better blur in the background, though a touch dark I still think.
Awe what a lovely smile. So exactly the same settings in this photograph as the one above, just a slightly different angle, that’s all, but I like this one best.
This was back before Christmas. I decided to test out some of my favorite votive holders that I sell. I had random ISO’s in these photographs, trying to work out how to get a very dark background as I wanted to use it as a slider image for my online shop. As you can see here, though blurred, for me too much information showing for a slider image and I wasn’t going to be dipping in to photoshop, Not quite yet anyway.
So we have ISO 280, F/3.5 and 18mm, quite a nice atmospheric look to this.
Here we have an ISO of 1250, I set the f value to 4 which changed the shutter speed to 1/100 seconds. What’s the difference? I think the first is clearer with the ISO being of lower value. However the background is indeed darker.
You can keep up with my other photography classes by clicking the link here: Photography Classes
So that is all for now folks. If you decide to join in, please copy in a link to your post in the comments section. It would be great to see some other examples of aperture priority.
Until next time, Justine xx