Aperture changing with zoom (1 Viewer)

OK, so I know I am not very bright, and I have no doubt you will be hearing from me a lot over the next few weeks/months, as I get to know my new coolpix4500, but I cannot for the life of me understand some of the instructions!

In both the Eagleeye info and Andy Bright's info on settings etc. it says to go for the smallest f number you can in Aperture priority mode and let the camera sort out the shutter speeds (at least I think that's what it says!). In the coolpix manual it says

"Unless ON is chosen for fixed aperture in the zoom options sub menu the apperture will change as the camera is zoomed in or out".

Well, I've set this to ON and the aperture still changes. When on no zoom it is on 2.6, half zoon (2x) it is on 3.9 and full zoom 5.0. What am I doing wrong? How do I get it to stay on 2.6?

I am trying to follow the instructions so that I can set the camera before trying it out for the first time with a scope.

Cheers

Chris

Hi Chris,

The camera is operating as it should. The advice should read 'go for the smallest f-stop for the amount of zoom you are using'.

My interpretation is that when digiscoping at such extreme focal lengths, aperture has little effect on depth of field. Between widest aperture and smallest as in f2,6 v f5,1 there will only be a few mm difference in depth of field which is hardly worth considering. More important is trying to get the fastest shutter speed in order to stop / reduce the effect of camera/scope shake and movement in the subject. f2,6 will always give a faster shutter speed than f8.

Likewise the change in aperture with changing zoom lengths. A shorter zoom length lets more light into the lens than a longer zoom length - on most cameras that is - including the Nikon CP4500. At no zoom on the CP4500 max aperture is f2,6 but at 4x zoom on the Nikon, maximum aperture is around f5,1. However if you want you can increase the aperture quite considerably - useful for 'normal' camera use but not for digiscoping due to the corresponding drop in shutter speed.

Clear as mud I dare say ?

One point though is 4x zoom is rarely of much use when digiscoping due to very soft images. I have had some reasonable ones occasionally but it's the exception. Much better to stick to 3-3.5x optic zoom. Essentially I usually zoom up to maximum and then 'zoom back' until the white zoom indicator moves back one jump. Obiously shorter zoom lengths are good too.

Thanks, Ian.

I always find it a bit difficult when buying new things as I have no idea whether they are actually working as they should. Many years ago I struggled with my first microwave because I thought I was doing something wrong and couldn't understand why everything turned out burnt in one spot! After several weeks ("Why didn't you bring it back sooner?") I found out it was faulty!

So, better safe than sorry from then on! (Even if I do feel a bit of a prat sometimes!)

Chris

Just popping in to say I'm having a similar problem figuring out my new (used) 990. I cant for the life of me find how to set the aperature and shutter priorities. The manual says to press the mode button while turning the control dial and I should have four options. All I see when I do that is the EV setting. So at this point I dont know if I'm really slow and missing a basic concept, or whether the camera is faulty. I admit I'm not easily understanding all those symbols and settings and I have no idea what an F-stop does..lol.. so wouldnt know if its me or the camera thats not functioning correctly.

Bev

Balego said:

Just popping in to say I'm having a similar problem figuring out my new (used) 990. I cant for the life of me find how to set the aperature and shutter priorities. The manual says to press the mode button while turning the control dial and I should have four options. All I see when I do that is the EV setting. So at this point I dont know if I'm really slow and missing a basic concept, or whether the camera is faulty. I admit I'm not easily understanding all those symbols and settings and I have no idea what an F-stop does..lol.. so wouldnt know if its me or the camera thats not functioning correctly.

Bev

Click to expand...

Hi Bev, if it's a used cp990 someone may have altered what the function buttons do...you can assign different functions to either function button. Try the other function button and rotate the dial (at same time)... If this doesn't have the desired effect you will need to go into the menu settings (set up menu) and access 'controls'... here you can assign different functions for the two buttons.... you'll want 'mode' on one of them.
regards,
Andy

Thanks Andy for the information. I didnt know I could set the functions so will explore that. I did find the missing A, M, and S after another thread recommended resetting the camera to default and starting over, when someone else had the same problem locating them. I did this and although it seemed all my settings were still there, the elusive letters suddenly appeared when I pressed the function 2 button. They werent under the mode button as the manual stated they should be. This sure is a whole new learning curve for me, so I'm following these threads with much interest. Thanks again.

Bev