Nikon aperture Help

[Lee85]

Hey Everyone, 

So i bought a new camera and i only had chance to have a go at imaging some dso last night but ive found a problem and im hoping there is a way round this. first problem was that when i took the lense of my camera Nikon D5100 the camera displays no lense attached. Ok it needs to be in manual ive found to get past this but also when i take the lens off the aperture closes to im guessing maybe f25 ish and its not what im after is there anyway of taking the lens off but keeping the aperture wide open? 

Thanks ) 

[andyboy1970]

Confused, the aperture adjustment is performed inside the lens not the camera, I suspect it is only displaying f25 because it has no idea what the f ratio is.

[ronin]

At a guess and it is no more I would suspect that f/25 is a default for no lens attached. Any aperture change system would be I suspect in the lens not the camera body.

Don't have a Nikon but in Manual my camera has me set the ISO, exposure time and focus. I have to give it an aperture (usually f/5 with lens on) this is done by going to the "A" setting and selecting something there.

In Manual although I set things most are previously done under other camera selection options.

Exposure length is under "S",

Aperture is under "A"

ISO is completely different button.

Then when I want Manual "M" I select that and the camera uses the "S" and the "A" setting that are under those selections.

I spend a lot of time tracking down where to set bits because Manual settings are not under Manual. Manual seems to mean use the settings under "S", "A" and the ISO and ignore what the camera would do.

As it is a fully manual selection the camera will just take the values you set, aperture if attached to a scope is somewhat irrelevant the scope is whatever it is, for safety set to camera to something faster, like f/2, f/4. I say this as if there is a shutter inside the camera (still think unlikely) then it will be set wide enough.

Find "A" and set iot to f/4, then remove the lens with the camera selection set to "M". I would think that it then defaults to f/4

Switch off, remove the lens and switch on, then see what the aperture is.

I would also ask if the aperture setting is in the camera or the lens.

[Lee85]

cool thanks for the info. ive done abit of reading and i think that the d5100 might have the aperture ring inside the camera if im correct and this will cause problems cause its held in place by a spring when the lens it attached so when i take the lens off the aperture closes down.. im trying to find a way around this but it might end up with me going back to canon instead.. 

[jgs001]

With the lens removed, look in the lens mount... If there are any aperture blades in the body, you will see them close down there. If you don't see the whole in the body closed off, and can fully see the mirror etc, then they will be in each lens. I suspect that this would also probably require a new set of lenses just for this camera, and I can't see any manufacturer wanted to do that, as the reason for dSLR's and maintaining lens mounts is to provide easy access to the existing lens range. 

[davew]

What is it you're trying to do Lee ? Use the DSLR on your 150?

When you take the lens off the camera it will show an error code. That's good and not a problem. Even Canon's do that In Nikon's case it's normally F - - . It doesn't matter what the lens does because you're going to put the caps on it and put it away.

Attach the scope / T adapter ( If you have one ) and DSLR. Turn the camera on and switch to M. Use the command dial to set the time. If the F number shows on the top plate display it's just remembering what the setting was before you took the lens off.

Can you direct me to the page in the manual that shows an internal diaphragm and spring.

Dave.

[rob0971]

My Nikon shows f0 with no lens attached or if fitted to the scope. The lens has the iris in it to provide the aperture. The camera has no iris built in. The camera only tells the lens what aperture is required for your exposure.

[rob0971]

Just to add, when coupled to your scope, the effective aperture or focal ratio will be what the scope is (f8?).

Take no notice if it says its f25.

[Psychobilly]

Older and Prosumer Nikon lenses used to have a manual aperture ring... This has been dropped of sone of the newer lenses the iris diaphragm is in the lens but its controlled electronically from the camera body - Canon did the same...

Canon lenses can be left stopped down by removing the lebs with the aperture stopped down ...

Badly typed on my Galaxay S4 in Tapatalk4