Having small problem with lens.

[ChrisJuliano]

Wow its almost like I post a thread with questions or problems every other day.
Sorry, but I just got my sigma 105mm macro lens, and was extremely impressed, in the box I got a extension hood and screwed it on gently.

Im extremely good with my stuff so when I say gently, it was extremely gentle.

And took lots of shots, went to take it off and wont come off, I tried hard enough to where my vains were popping out of my hand almost. Which is FOR SURE not good for the lens so I am not going to try again because it just might break.

Help please?

 

[Josh66]

Hmm... Yeah, the lens hood should come off pretty easily. Maybe you got it on there cross threaded? (That's the only thing I can think of.)

 

[ChrisJuliano]

Crossthreaded?


Also on my lens it has the f-stop (i think thats what its called) #'s, like 2.8 to 32. What does that effect and why does my nikon d40 tell me to put on max and lock or something?

 

[Josh66]

Crossthreaded?

(′krös ′thred) (engineering) To screw together two threaded pieces without aligning the threads correctly.


Some of my hoods screw on (more like a quarter or half turn - but it's still possible to cross thread them), some just snap on. Does your's screw on?

 

[Josh66]

Also on my lens it has the f-stop (i think thats what its called) #'s, like 2.8 to 32. What does that effect and why does my nikon d40 tell me to put on max and lock or something?

Yeah, that's the f stops or aperture of your lens.

It affects DOF and exposure (if you adjust the aperture, you must also adjust the shutter time to keep the same exposure). Not sure what the max/lock thing is all about - I don't have any Nikons. But - It's probably trying to tell you that you need to adjust the aperture (or shutter speed, or ISO) to get a good exposure.

 

[ChrisJuliano]

Ahhh so confusing haha. Something is for sure wrong, out of 400 shots like 99% of them had a very small dof, which made none turn out. Idk what to do.

And hmm, its screw on but it sure seemd like it went on perfectly alligned, it spun like 15 full times before it felt locked into place.

 

[Josh66]

If it was cross threaded, you probably would have noticed that something was wrong as you were screwing it on (some people might not notice, but it would feel "tighter than it should be"). It might just be stuck (I'm not sure what type your's is - all of mine are really easy to put on or take off, you don't even have to make a full turn).

 

[ChrisJuliano]

Hmm yeah I doubt the cross threading because it was very smooth.

 

[Kegger]

You have to turn the aperature ring on the camera to 32 and lock it with a little switch that's on the body near said ring.

 

[ChrisJuliano]

Got it locked, but I want a larger DOF so why cant I shoot on it lower?
And why do I need to lock it on 32?

 

[djacobox372]

Got it locked, but I want a larger DOF so why cant I shoot on it lower?
And why do I need to lock it on 32?

Once it's locked you can set the aperture via the in-camera controls.

 

[ChrisJuliano]

Why cant I just use it on the lens?
Whats the point of it if I cant use it on the lens?

 

[photographyaddict]

does it have a warranty? it doesnt sound right. i never heard of this kind of problem with lens hood before.

 

[ChrisJuliano]

Yes it has warranty.

 

[Bifurcator]

If the lens hood is plastic set you camera in the freezer for about 15min. and it might unscrew real easy.

It the hood is metal try to heat it up in some way. you don't want it hotter than about 90˚ or 100˚ (F) though. Just "very warm".