ppage Loc: Pittsburg, (San Francisco area)

I have read many times that crop factor also has to be applied to the aperture.

My Nikon P900 has a 35mm equivalent focal range of 24mm-2000mm. This is done with a tiny sensor and a huge crop factor of 5.6. The actual (optical) focal range is roughly 4.3mm-357mm.
Here's what happens to the apertures:
2.8 = f/11
4 = f/22
5.6 = f/31
8 (max available) = f/45

These numbers seem a little dramatic to me. Perhaps it is not done so literally with a point and shoot?
Is there some other secret sauce being used to keep these in the realm of normal?
Am spending too much time with my calculator and not enough time out shooting?

RobertW Loc: Breezy Point, New York

I also have a P900 and an old P&S and look forward to seeing answer(s) to this one

JPL

Maybe you have read it many times that crop factor has to be applied to the aperture. But that is nonsense. Why does the crop factor have to be applied to the aperture? Tell me why. All you have to do is think about the P900 lens as a 4.3-357 mm lens. That is what it is and nothing else.

BebuLamar

What it meant is that.
1. If you set your camera at the equivalent 35mm focal length of say 50mm. Set your aperture to 2.8 and do the same thing with a FF camera and set the aperture to 11. You have about the same DOF.
2. My Df FF camera has 16MP the same as yours so if you shoot at ISO 100 it said that I can shoot at ISO 6400 and have about the same amount of noise.

Is it true?? Not about the noise because it depends on a lot of other factors. The DOF yes.

n3eg Loc: West coast USA

Now we're talking equivalence, which is worse than Nikon vs. Canon.
Yes, point and shoots have more diffraction, which is why you usually get very processed JPGs out of them.
In the real world, if you get acceptable photos, it doesn't matter - except for DOF, which does follow the FF "equivalent" aperture.

Linda From Maine Loc: Yakima, Washington

I have a Canon sx50. Shallow depth of field is hard to obtain at wider angles, regardless of f/stop. I did controlled tests a couple of years ago, the main conclusion being that using aperture priority with a bridge camera is a waste of time. f/4.0 (my largest available) looked the same as f/8.

An easier way to achieve shallow depth of field is to stand back and zoom in on your subject. Forget numbers and go do some controlled tests via the zoom on subjects that interest you.

I just discovered this chart (see below). You're actually quite limited in aperture range anyway, once you start to zoom:

Djedi

I have the same camera which I carry around to fulfill my "always have a camera" rule. It is a great little camera, but has its limitations and shallow depth is definitely one of them.
If I want a great portrait with blurry background, I will pull out my 85mm f1.8. on a D800.

ppage Loc: Pittsburg, (San Francisco area)

Maybe a better way to have put that would be that DOF is affected by the crop factor. The aperture is what you set it at but the size of sensor has a great deal to do with what you will get for DOF. Thus 2.8 is 2.8 but you can expect to get a DOF equivalent to f/11 on a full frame when multiplying the aperture setting x 5.6. Brian Peterson speaks about this as being a nice advantage of P&S cameras but the flip side is poor isolation at the maximum apertures compared to FF and other larger sensors. Tony Northrup has tackled it many times and has had pitched battles over it every time. Now I am thinking the whole thing is just academic. The P900 takes surprising good images when zoomed all the way in at 2000mm. I regularly get nice separation by having background far away from the subject.

(Download)

BHC Loc: Strawberry Valley, JF, USA

4.3 X 5.6 =24
357 X 5.6 = 1999
There's your 24-2000

photoman022 Loc: Manchester CT USA

We photographers make life too difficult for ourselves! I'm told that my 55mm lens on my crop sensor is really an 85mm lens -- I gave up on it all a long time ago. I don't waste a lot of time thinking about those things! If I want to shoot my CS at 55mm, I think 55mm. I know that I won't get as much area as a FF, but hey, I can't afford a full frame camera!

All that being said, a smaller sensor affects depth of field. The smaller the sensor, the less depth of field you have to play with. That's a given; when I use my Fuji SX8600 I know this fact somewhere in the depths of my mind, but I don't think about it. I use my Fuji in circumstance where I want a longer lens (because I can't afford a 400-600 Tamron) and work within the depth of field limitations.

The f/2.8 on my Fuji is an f/2.8. I don't worry about its aperture equivalent on my CS or on the FF (I don't have). I use the camera I have with me and enjoy getting great photos.

whitewolfowner

Absolutely bunk what you have heard. f5.6 is f5.6.

BebuLamar

I don't think so! It's just plain fun to talk about crop factor! When I use the camera I simply use only the FF. For better or worse it has the crop factor of 1 so I don't need no math!