My Nikon AF-S 35mm 1.8G lens is not up to the mark - why???

[CtrlU]

Dear Friends,
I own a Nikon D5100, and have been using the 18-55 kit lens along with it, as you all know that this kit lens is superb for macros and closeups but not so great for landscape photography since the lens lacks the sharpness and also is crappy for low light shots, .
I heard lots of users praising the capabilities of the 35mm 1.8g prime lens, regarding its sharpness and its ninja ability to capture low light shots without sacrificing on shutter speed and iso .
So i decided to get my self this prime lens. but to my horror it all turned out to be wrong.


so i did a comparison test to find whats wrong.. pls note that all shots were made in aperture priorty mode and both at 35mm focal lenghts and all at the same lighting conditions and at ISO 100.
1. the first was a shot of some oranges on a table with the morning sun rays gleaming onto them.
first the 18-55 kit lens fixed at 35mm, the aperture was fixed at 5 the highest aperture the lens was capable of when zoomed to 35mm. when metered the shutter speed was fixed at 1/80th of a second. OK went ahead and took the shot
Now with the 35mm lens , again i fixed the aperture at 5, since i wanted to compare both the shots, But heres were the problem starts, When i metered the shutter speed was fixed at "1/60th of second" NOW HOW ON EARTH IS THAT POSSIBLE. why did the shutter speed become lower than the kit lens. i thought this prime lens was a fast one, and took superb shots in low light conditions. I really thought that the shutter would be meterd at somewhere in 1/100 and 1/200 range.
Why is this happening.


2. So i decided to take an out door landscape shot to check if this was the case again.


the shot was a rice paddy filed at 8:00 in the morning, sunrays shining brightly over the green rice field.
First with the kit lens, at 35mm, the aperture was fixed again at 5, when metered shutter speed was fixed at 1/3200 of a second. fast isn't it....OK
now with the prime lens and to my horror the shutter speed was fixed at 1/1600 of a sec.... WHAAAT lower than the KIT lens again.... WHATS GOING ON... why this lens is capable of capturing more light in right... then what wrong with the lens.




MY question to all is ....
is there something wrong with my lens, if yes how to find whats wrong and...
Please guys i need your expert advice... I EXPECTED more from this lens and now i am sad.

 

[Raj_55555]

Why don't you post the sample pics for all of us to see. That way we will have a better idea of what you're dealing with!

 

[PaulWog]

1 - f5 is f5 on any lens. If you set your camera to ISO 100 and an aperture of f5, your shutter speed should be the same regardless of the 35mm lens you're putting on there. The reason why there was a difference (1/80 to 1/60) was because you were using aperture priority. Aperture priority will vary based on just very slight changes. Your 35mm 1.8G won't magically allow a faster shutter speed at f5. That would be like picking up a brand new car and asking why you didn't get to work quicker going 50km an hour in that brand new car, even though it's supposed to be able to go fast. You weren't bringing your 35mm 1.8G down to f1.8, so of course you don't get a faster shutter speed.

2 - Again, you are exposing your shots entirely differently. If you're shooting at f5, both lenses will bring in the same amount of light, and require the same shutter speed. There are options with aperture priority which you need to utilize: 1) You need to switch between spot metering, center-weighted metering, and matrix metering. Get to know each one, you have to use all three if you're picky and use aperture priority 100% of the time. 2) You need to know how to use your exposure compensation tool. When you use aperture priority, you can set your exposure down a stop from what the camera meters for, so if your camera is metering for 1/1600 of a second normally, it will then set it to 1/3200 as you wanted it.

Just a few more points:

1) The 35mm 1.8G is good for low light shots because you can use it at f1.8. If you're shooting at f5, it's going to perform the same as your 18-55 kit lens. In fact, your 18-55 kit lens will likely perform better if it has VR built in.
2) The 35mm 1.8G will not get sharp shots at 1/60 of a second. No 35mm lens on a crop sensor camera will consistently get tack-sharp shots at 1/60 of a second hand-held on a consistent basis (unless if you have VR). You need to bump your ISO up, or get your aperture to a quicker speed in order to utilize the low-light capabilities of the 35mm 1.8G.
3) For landscapes, if you're shooting in poorly lit conditions (ie. you need 1/60 of a second to get an f5 shot with your 35mm 1.8G), you should use a tripod, and time your shots to 10 seconds after you press the shutter so you don't vibrate the camera. You'll get super sharp shots. Alternatively, you can bump your ISO up for quicker hand-held shots, or use your 18-55mm (if it has VR), since it's likely not too bad for hand-held landscapes at 1/60 (because of the VR).

 

[korreman]

Well, the actual amount of light coming in will depend on the individual lens. Not all the specifications and aperture sizes are precise, so your kit lens might let more light in at f/5 than your 35mm.

That being said, the whole point of that 35mm is the ability to open up your aperture all the way to f/1.8, giving you lots of more light. Going from f/5 to f/1.8 will give you about 3 stops of light extra. That means, you'll be going from a shutter speed of say, 100 to 800.

Oh, and I suspect that the "problem" is rather the metering than the lens. If you try to take a picture where your lens was pointing at, or close to, the sun, the metering will have a hard time trying to get a correct exposure, and the shutter speed can vary greatly like you saw. Also, the camera can easily switch from 1/60 to 1/80, all it takes is for the photographer to point towards a slightly darker subject, say, from a white wall to a bookcase. Remember, 1/80 to 1/60 is only a third of a stop, 1/60 is only one step lower on the camera, so it might sometimes change on it's own, with the same lens and subject.

If you want to do a real test, you should switch to manual mode, and photograph the exact same subject with the exact same exposure settings, then compare the two photos. Does one look darker than the other? Check the histogram if you want, but if it's not visible to the naked eye, but then the difference is essentially negligible.

 

[CtrlU]

1 - f5 is f5 on any lens. If you set your camera to ISO 100 and an aperture of f5, your shutter speed should be the same regardless of the 35mm lens you're putting on there. The reason why there was a difference (1/80 to 1/60) was because you were using aperture priority. Aperture priority will vary based on just very slight changes. Your 35mm 1.8G won't magically allow a faster shutter speed at f5. That would be like picking up a brand new car and asking why you didn't get to work quicker going 50km an hour in that brand new car, even though it's supposed to be able to go fast. You weren't bringing your 35mm 1.8G down to f1.8, so of course you don't get a faster shutter speed.

2 - Again, you are exposing your shots entirely differently. If you're shooting at f5, both lenses will bring in the same amount of light, and require the same shutter speed. There are options with aperture priority which you need to utilize: 1) You need to switch between spot metering, center-weighted metering, and matrix metering. Get to know each one, you have to use all three if you're picky and use aperture priority 100% of the time. 2) You need to know how to use your exposure compensation tool. When you use aperture priority, you can set your exposure down a stop from what the camera meters for, so if your camera is metering for 1/1600 of a second normally, it will then set it to 1/3200 as you wanted it.

Just a few more points:

1) The 35mm 1.8G is good for low light shots because you can use it at f1.8. If you're shooting at f5, it's going to perform the same as your 18-55 kit lens. In fact, your 18-55 kit lens will likely perform better if it has VR built in.
2) The 35mm 1.8G will not get sharp shots at 1/60 of a second. No 35mm lens on a crop sensor camera will consistently get tack-sharp shots at 1/60 of a second hand-held on a consistent basis (unless if you have VR). You need to bump your ISO up, or get your aperture to a quicker speed in order to utilize the low-light capabilities of the 35mm 1.8G.
3) For landscapes, if you're shooting in poorly lit conditions (ie. you need 1/60 of a second to get an f5 shot with your 35mm 1.8G), you should use a tripod, and time your shots to 10 seconds after you press the shutter so you don't vibrate the camera. You'll get super sharp shots. Alternatively, you can bump your ISO up for quicker hand-held shots, or use your 18-55mm (if it has VR), since it's likely not too bad for hand-held landscapes at 1/60 (because of the VR).

thanks so if i am not mistaken the 35mm prime lens is fast simply because it can go all the way down to f1.8. I understand the various metering options available, but aren't prime lenses supposed to be superior than telephoto lens when it comes to capturing more light in, i mean the quality of the glass used in the lens and so on... anyways thanks for the insight, i expected it to perform faster at the same f stop thats all...

 

[jaomul]

As said above f5 is f5 on any lens, exposure is a combination of set f number, shutter speed and iso. Where at 35mm say f5.6 on your kit lens may give 1/100th sec at iso 100,your 35mm will at 5.6 be the same, however you could put the prime to f4 and get 1/200 sec, or f2.8 to give 1/400 sec, and then even f2 to give 1/800 sec. Your depth of field will reduce as the aperture opens up.

 

[CtrlU]

Well, the actual amount of light coming in will depend on the individual lens. Not all the specifications and aperture sizes are precise, so your kit lens might let more light in at f/5 than your 35mm.

That being said, the whole point of that 35mm is the ability to open up your aperture all the way to f/1.8, giving you lots of more light. Going from f/5 to f/1.8 will give you about 3 stops of light extra. That means, you'll be going from a shutter speed of say, 100 to 800.

Oh, and I suspect that the "problem" is rather the metering than the lens. If you try to take a picture where your lens was pointing at, or close to, the sun, the metering will have a hard time trying to get a correct exposure, and the shutter speed can vary greatly like you saw. Also, the camera can easily switch from 1/60 to 1/80, all it takes is for the photographer to point towards a slightly darker subject, say, from a white wall to a bookcase. Remember, 1/80 to 1/60 is only a third of a stop, 1/60 is only one step lower on the camera, so it might sometimes change on it's own, with the same lens and subject.

If you want to do a real test, you should switch to manual mode, and photograph the exact same subject with the exact same exposure settings, then compare the two photos. Does one look darker than the other? Check the histogram if you want, but if it's not visible to the naked eye, but then the difference is essentially negligible.

Thanks, i,ll try manual mode and compare the photos... to see the difference, my metering was at the same spot for both shots, so not much difference there, but i expected more light to be captured by the prime lens,

i saw a video some where on youtube comparing a night shot of a car poorly lit by street light. when using the kit lens the car parked under was barely visible, but when he switched over to 35mm, that car was visible to a large extent. he used the same settings on bot, now will have to try that out at night to see how my 35mm performs..

 

[CtrlU]

As said above f5 is f5 on any lens, exposure is a combination of set f number, shutter speed and iso. Where at 35mm say f5.6 on your kit lens may give 1/100th sec at iso 100,your 35mm will at 5.6 be the same, however you could put the prime to f4 and get 1/200 sec, or f2.8 to give 1/400 sec, and then even f2 to give 1/800 sec. Your depth of field will reduce as the aperture opens up.

Ok, you are saying that if th e f-stops on both lens are fixed to say f5.6 the shutter speed should be the same, but thats not the case here, the shutter speed is always lower on the 35mm and not the same, yes, i understand that if i bring the fstop to 1.8 i could get faster shutter speeds. but as you said my depth of field will reduce and i dont want that. so in such a scenario my only option would be to bump up the iso...

well i dont know, but i just cant seem to accept the fact that my prime lens does not capture more light than my kit lens... anyways thanks for the answer

 

[jaomul]

F stops should give same shutter speed. In this case I'd say that 35mm on your kit lens may be slightly different than 35 on the prime. You are turning kit and aligning with the 35 approx. F stop is mathematics, so slightly difference may make slightly difference in speed. I would go to a room with artificial unchanging light, set up your kit on a tripod and spot meter at 35mm on a subject. See how it goes then

 

[korreman]

1 - f5 is f5 on any lens. If you set your camera to ISO 100 and an aperture of f5, your shutter speed should be the same regardless of the 35mm lens you're putting on there. The reason why there was a difference (1/80 to 1/60) was because you were using aperture priority. Aperture priority will vary based on just very slight changes. Your 35mm 1.8G won't magically allow a faster shutter speed at f5. That would be like picking up a brand new car and asking why you didn't get to work quicker going 50km an hour in that brand new car, even though it's supposed to be able to go fast. You weren't bringing your 35mm 1.8G down to f1.8, so of course you don't get a faster shutter speed.

2 - Again, you are exposing your shots entirely differently. If you're shooting at f5, both lenses will bring in the same amount of light, and require the same shutter speed. There are options with aperture priority which you need to utilize: 1) You need to switch between spot metering, center-weighted metering, and matrix metering. Get to know each one, you have to use all three if you're picky and use aperture priority 100% of the time. 2) You need to know how to use your exposure compensation tool. When you use aperture priority, you can set your exposure down a stop from what the camera meters for, so if your camera is metering for 1/1600 of a second normally, it will then set it to 1/3200 as you wanted it.

Just a few more points:

1) The 35mm 1.8G is good for low light shots because you can use it at f1.8. If you're shooting at f5, it's going to perform the same as your 18-55 kit lens. In fact, your 18-55 kit lens will likely perform better if it has VR built in.
2) The 35mm 1.8G will not get sharp shots at 1/60 of a second. No 35mm lens on a crop sensor camera will consistently get tack-sharp shots at 1/60 of a second hand-held on a consistent basis (unless if you have VR). You need to bump your ISO up, or get your aperture to a quicker speed in order to utilize the low-light capabilities of the 35mm 1.8G.
3) For landscapes, if you're shooting in poorly lit conditions (ie. you need 1/60 of a second to get an f5 shot with your 35mm 1.8G), you should use a tripod, and time your shots to 10 seconds after you press the shutter so you don't vibrate the camera. You'll get super sharp shots. Alternatively, you can bump your ISO up for quicker hand-held shots, or use your 18-55mm (if it has VR), since it's likely not too bad for hand-held landscapes at 1/60 (because of the VR).

thanks so if i am not mistaken the 35mm prime lens is fast simply because it can go all the way down to f1.8. I understand the various metering options available, but aren't prime lenses supposed to be superior than telephoto lens when it comes to capturing more light in, i mean the quality of the glass used in the lens and so on... anyways thanks for the insight, i expected it to perform faster at the same f stop thats all...

What you do get is a superior image quality on the 35mm. Yes, same f-stop is about the same light coming in, but it'll be a lot sharper on your new lens! Plus, the lower aperture is really great to have. I think you should be quite happy with this new lens, it'll perform well!

 

[CtrlU]

F stops should give same shutter speed. In this case I'd say that 35mm on your kit lens may be slightly different than 35 on the prime. You are turning kit and aligning with the 35 approx. F stop is mathematics, so slightly difference may make slightly difference in speed. I would go to a room with artificial unchanging light, set up your kit on a tripod and spot meter at 35mm on a subject. See how it goes then

mmm. right... i would like to try your suggestion with artificial light and set up on a tripod and spot meter at 35mm, i'll see how that goes an post the results... thanks

 

[CtrlU]

What you do get is a superior image quality on the 35mm. Yes, same f-stop is about the same light coming in, but it'll be a lot sharper on your new lens! Plus, the lower aperture is really great to have. I think you should be quite happy with this new lens, it'll perform well!

\

yes, ill post some comparison shots to check the sharpness... well hoping for some improvement there,, thx by the way

 

[korreman]

What you do get is a superior image quality on the 35mm. Yes, same f-stop is about the same light coming in, but it'll be a lot sharper on your new lens! Plus, the lower aperture is really great to have. I think you should be quite happy with this new lens, it'll perform well!

\

yes, ill post some comparison shots to check the sharpness... well hoping for some improvement there,, thx by the way

Remember that different lenses are sharpest at different aperture sizes. The 35mm will probably be sharpest at f/5.6, while the zoom, well, I don't know about the zoom.

 

[480sparky]

..... i expected it to perform faster at the same f stop thats all...

What do you mean 'perform faster'?

If both lenses are set to f/5, how can one 'perform faster' than the other?

 

[korreman]

..... i expected it to perform faster at the same f stop thats all...

What do you mean 'perform faster'?

If both lenses are set to f/5, how can one 'perform faster' than the other?

I still think he's getting the basics of this. That being said, different lenses can have different transmission rate. Some are better coated, and reflect less light back, thus transmitting more light to the sensor. I don't know how much the transmission rate changes though.