Prime lens - good idea? Bad idea?

Spud83

I have an event coming up in a couple of weeks that I want to shoot. It's an indoor event with a mix of theatre and acrobatics on display likely in low light conditions. So I was thinking a prime lens might be good for such an event. Flash photography is more than likely not welcomed.

I'm looking at a Nikon AF-S 35mm F1.8G DX Lens for a Nikon 3100 and was wondering am I making the right choice or wasting my money?

My thoughts are the faster shutter speed that I can achieve with the greater aperture will help.

magicbastarder

what's the alternative - what lens(es) do you currently own?
i have the lens you're asking about above and it's on the camera 80% of the time.

Spud83

I have the kit lense 18-55mm, and also a 55-200mm.

I also think the prime lens is a good lens to have regardless, but just wondering would I find it useful for the above event.

sheesh

depends on your scope for movement with a prime you 'zoom with your feet'

on a cropped sensor a 50mm is more like a 80mm so if you are far back enough your fine.
next problem is depth of focus. At a local concert I was 30-40 feet back from the stage, I ended up with an amazing number of shots where the microphone stand was perfectly in focus with the performers face being slightly out of focus, very frustrating! Looks fine in camera take it home and then you see it.

magicbastarder

sheesh wrote: »

on a cropped sensor a 50mm is more like a 80mm so if you are far back enough your fine.

the lens in question is a 35mm though.

eoglyn

I wouldn't purchase a lens specifically for one event. But if you are going to buy a lens anyway, you won't go too far wrong with that 35mm 1.8.

Although it is a savage lens - I'm not sure it'll be the most suitable for the event that you are shooting. You'll know what the 35mm focal length looks like from your zoom lens - its not too 'zoomed in'. If you have the manoeuvrability to get close to the action you'll get really fine pictures, if not, maybe the lenses you have might be better - boosting the iso a bit. Experiment beforehand to see what levels of noise you are happy with. At the very least a noisy black and white picture will be better than no picture at all.

Even if flash is allowed it might not be a good idea - blasting a display that uses flames and lights with a flash will most likely kill any intended drama.

Spud83

Thanks for the info guys, there will be plenty of scope for movement at the event. Its not going to be in a big venue, and not seated in anyway. I know its not smart to buy a lens for one event but I've also believe I would have other uses for the lens (heard lots of good things on it)

The reason I'm thinking of the 35mm over the 50mm is because on the cropped sensor it will act more like a 50mm which will give me more scope to frame things, and more scope of cropping.

Also the performers will be front of the stage so I don't think focus will be an issue, no microphones etc will be infront of them.

eoglyn

Well i'd take a prime over a zoom all day, so i don't think you'll regret the investment.

Preferences for focal lengths are very personal though. Sometimes you just prefer one over the other as that's how you see the world, or it just suits your photography. As you have a zoom with both FLs i suggest you practice on a photo walk using your zoom as a prime - an hour at 35mm and another hour at 50mm.

By the end of it you'll definitely know which FL is for you.

sheesh

magicbastarder wrote: »

the lens in question is a 35mm though.

Doh! sheesh not read good! should be better so.

Also remember that if the show is properly lit that there might not need to go to the full f1.8.

mystic86

Spud83 wrote: »

The reason I'm thinking of the 35mm over the 50mm is because on the cropped sensor it will act more like a 50mm

Hey, double check that - I have a Nikon 35mm f1.8 and it is a DX so the crop factor won't come into play.

I do also have a 50mm f1.8 which is a FX lens so it's effectively 75mm on my camera body (similar one to yours).

Echoes675

this lens is a really fantastic lens at this focal length. It's sharp and really swallows light like a black hole! My only concern would be that your shots would be overly distant and you would need to get close to the performers to get tightly framed shots. I would advise this, set your zoom to 35 mm and leave it there. Now go out and spend an afternoon or two only using this focal length. You will get a real good idea whether this is the right focal length for what you want.
Aside from that as I said, if the focal length is right, this lens really is a winner.

Ben D Bus

mystic86 wrote: »

Hey, double check that - I have a Nikon 35mm f1.8 and it is a DX so the crop factor won't come into play.

I'm pretty sure a 35mm is a 35mm whether or not there is a DX badge on it. So it will be similar to a 50mm on a FF camera.

DaireQuinlan

Ben D Bus wrote: »

I'm pretty sure a 35mm is a 35mm whether or not there is a DX badge on it. So it will be similar to a 50mm on a FF camera.

Yes this is correct. The 'DX' tag that nikon sticks on some of its lenses just means that the lens doesn't have sufficient coverage for a full frame or 35mm film body. The focal length is the same regardless.

mystic86

I'm very confused

adox

mystic86 wrote: »

I'm very confused

The focal length stated on any lens is the focal length on a full frame camera. It doesn't matter whether(in the case of Nikon) it's a DX of FX lens, the same rule applies for the focal length stated.

DX specific lenses are made specifically for DX bodies and either won't work on and FX body or will show a big vignette, but the focal length of the DX lens needs to be multiplied by 1.5 to account for the crop factor of the DX sensor, when put on a DX body.

Your 35mm DX lens shows approx a 52.5mm view on your DX body and your 50mm FX lens shows approx a 75mm view on your DX body.

In other words, if you have a DX body, multiply the focal length stated on the lens by 1.5 no matter what type of lens it is. On the flip side, if you have an FX body the focal length stated on any lens will be reflected on the camera body.

magicbastarder

adox wrote: »

The focal length stated on any lens is the focal length on a full frame camera.

no, the focal length stated on any is the focal length on *any* camera. doesn't matter what camera it is. it's just that 35mm film was the default standard for people for so many years that the idea of 50mm being standard became cemented.

the focal length is a fixed physical property of the lens, and the 35mm frame is an arbitrary choice of a 'standard'. the standard 50mm was picked to match the format, not the other way around. the effect of how wide or narrow the image looks is a result of how big or small (in a relative sense) the lens renders the image on the recording medium - so a 90mm lens projecting an image onto a DX sensor, in which a postbox is rendered as 10mm high on the sensor, will look a lot bigger (i.e. more telephoto-y) in the resulting frame than a 90mm lens projecting the same 10mm image onto a large format film, which has a surface area 20 times the size, at a rough guess.

an aside - a 'standard lens' for pedants is one for which the focal length of the lens is equal to the diagonal measure of the format - so for 35mm film, a standard lens should actually be about 43mm.

mystic86

oh dear lord I am so confused!

So the kit lens which came with the body, which says 18-55, is actually 27-82.5?!?!

adox

magicbastarder wrote: »

no, the focal length stated on any is the focal length on *any* camera. doesn't matter what camera it is. it's just that 35mm film was the default standard for people for so many years that the idea of 50mm being standard became cemented.

Yes I stand corrected and worded it badly.

DaireQuinlan

mystic86 wrote: »

oh dear lord I am so confused!

So the kit lens which came with the body, which says 18-55, is actually 27-82.5?!?!

No. It's 18-55.

adox

mystic86 wrote: »

oh dear lord I am so confused!

So the kit lens which came with the body, which says 18-55, is actually 27-82.5?!?!

No its still 18-55. When you put it on your cropped sensor body, the sensor only captures a portion of the image that the lens projects on to it. Because its a 1.5 crop its the equivalent field of view of 27-82.5 on a full frame camera.

Think of when you crop an image in on your computer. Think of the original outside of the crop image as the image that the lens sees and the cropped inner image as the image that you cropped sensor body captures. In other words, its the size of the sensor that is affecting the size of the captured image and the perceived field of view. A cropped sensor by nature doesn't capture the full image.

magicbastarder

to use a really badly thought out analogy with car engines which i'm probably going to realise is fatally flawed halfway through explaining it - your car engine puts out a fixed amount of torque/horsepower. how fast your car accelerates then depends on the weight of the car.
so in this example, the focal length is the power of the engine, the sensor size is the weight of the car, and the acceleration is analogous to how wide or how long the resulting field of view is.
i.e. you don't say the engine is more powerful if you put it in a lighter car (because it accelerates faster); the engine power is fixed.

that doesn't really help, does it?

DaireQuinlan

mystic86 wrote: »

oh dear lord I am so confused!

So the kit lens which came with the body, which says 18-55, is actually 27-82.5?!?!

Actually, you know the best way to resolve all this confusion ? Don't think about it. Shoot away with your 18-55. Get comfortable and familiar with how it frames things at various focal lengths. What does it matter that on a different car the diesel engine will give you more acceleration than bigger wheels on a different sized prius (just to strain that analogy even more )

I never understood why this became such an issue with digicams. People shot for years with a variety of formats and never gave it a second thought. Then suddenly there's more useless verbiage about this on the internet than practically anything else. Paper, as my dad would have said, never refused ink. Also you probably can't write as much on a smaller piece of paper with the same sized pen and ... no ... NOO .... NOOOOOOEROEAIre

Ben D Bus

mystic86 wrote: »

oh dear lord I am so confused!

So the kit lens which came with the body, which says 18-55, is actually 27-82.5?!?!

No. But to get the same zoom range (to see the same range through the viewfinder and in the final image) on a full frame camera you would need a 27-82.5

pixbyjohn

Worth a read>>>>>>>>
http://www.slrlounge.com/school/cropped-sensor-vs-full-frame-sensor-tips-in-2/

DaireQuinlan

pixbyjohn wrote: »

Worth a read>>>>>>>>
http://www.slrlounge.com/school/cropped-sensor-vs-full-frame-sensor-tips-in-2/

... and the ensuing comment stream is a perfect example of the malformed gibberish that this topic seems to inspire in people.

W0LFMAN

Thought of getting prime lens with some extenders 1.4 or 2x extender it increases the aperture, but doubles your options.

pixbyjohn

DaireQuinlan wrote: »

... and the ensuing comment stream is a perfect example of the malformed gibberish that this topic seems to inspire in people.

Agreed, like most discussions. Some well informed and some not so. The article itself is worthy of a read though.

CabanSail

I hope the image I have made below helps to illustrate the difference between a lens of the same focal length on a Full Frame and Cropped sensor.

A lens is designed to illuminate a certain area. If it is only big enough to cover a smaller sensor then it cannot work on a larger sensor, but the focal length always stays the same.