question on lens

[bukitimah]

I owned 2 lenses. Afs 18-105 & afs 70-300 VR. F stop is 3.5 biggest. 18 mm seem adequate for me but 11 mm would be ideal for tight indoor apace.

I shoot almost anything and am toying with the idea of switching my 18-105 with a 17-50 mm lens with a lower f stop of 2.8.

Would the increase in aperture be of importance and would I be handicap with the 50-70 gap due the the change? Or should I keep the existing lenses and but a 50 mm f1.8 prime? What is my best option without breaking the bank?

[kklee]

Get a 50mm f1.8 prime follow by a 40mm f2.8 macro.

[bukitimah]

KKLee, can you explain the rationale? The 40 & 50 mm is quite close don't they?

[kklee]

As you had mentioned that you shoot everything, you present setup don't allow you to shoot macro ( hence the Nikon 40mm f/2.8 macro ) and you don't have something that you can use in lowlight or bokeh ( hence the Nikon 50mm f/1.8 )

An alternative is to look at functionality instead of overlapping of focal length. This way, you can shoot different genre.

[bukitimah]

Thank you KKL, I am using the Raynox over the kit lens and am quite happy with this set up. What bother me is portrait under low light. That is when I shoot people indoor and flash is not possible.

The other challenge is bokeh where you blur the background. For lens less than 70 mm do you think vibration control is important since we can increase speed due to smaller f stop?

[kklee]

Maybe you can give some examples of portraits under low lights you are trying to achieve.
To different people, it can mean differently e.g. portraits in low light can be static posed shots or dynamic candid shots.

I would say VR is always useful as it allows even slower speed depending on the lighting condition.

Here are some concerns if let's say you using 50mm (crop sensor)

- will the slight distortion to head shots be useful to the portraits you're trying to achieve

- like on the non-G Nikon 50mm F/1.8, at F/1.8, the image is a bit soft, AF system needs to be accurate, choice of AF point must be right and if light is low, AF can go hunting while trying to fix focus.
That is if you turn off the irritating focus assist lamp.

[bukitimah]

I guess I use the word portrait too loosely. What I meant is shots of people in general especially in door during events. In such situation, flash is difficult when you are further away from the subject.

I would usually need to increase ISO to 400, increase exposure compensation and the biggest aperture which in my case is only 4.5. I have no choice but to reduce speed to 1/80. The image will be soft. Increasing Iso will make it noisy. I think a f2.8 would do a better job.

Can you also advise the function and situation when the 50 mm f1.8 is useful? In door a bit tight whilst outdoor too short or both Ok?

[kklee]

Actually lens choices for is rather difficult especially for crop sensors because of the 1.5x multiplier.

Example, Nikon's range of f/2.8, you have the
17-55 (DX 25.5-82.5) $2939 <--- Non VR
24-70 (DX 36-105) $3339 <--- Non VR
and 70-200 (DX 105-300) $3699

The question really is to decide which lens is the most suitable.
The 17-55 and 24-70 is non-VR, wide open at the longer focal length, VR would definitely be useful.

From f/2.8 to f/4 is about 1-stop. If the shutter is 1/80, one stop you get 1/160.
If you reverse the ways of looking at things, if let's say the ambient is 1/15 at f/4, using f/2.8 you will get 1/30 and this is where VR would be useful.

For your scenario of increasing ISO to 400, increase exposure compensation and reduce speed to 1/80, I am not quite sure why the image is soft, but for the
noise part, if the image is not correctly exposed, noise is more obvious.

For events, quite a few instances you'll need to use flash, while it is possible to use f/2.8, in group shots, the DOF might be too shallow.

I find 50mm f/1.8 is suitable to take half body shots both in doors and outdoors and you're right, it is a bit tight. You need to move back a bit to compose the shot.
Likewise, 85mm f/1.8 is good for portrait, you just have to stand a bit further back for half body and quite far back for full body shots! So everything there is a compromise.

In my opinion, ease of use and cost effect would be using Nikon 18-105 VR with SB-900. If the Nikon most powerful flash cannot reach, you have to move closer.
In events, usually it is difficult to change lens and this is where having 2 bodies ( wide and tele ) helps.
Actually all these depends on your personal style, some folks just use a single 35mm.

[bukitimah]

Nikon lenses are great but beyond my budget. I am likely to source for 3rd party lens. Would the same crop factor apply for a DX camera?

[Poseidon]

If you have a DX camera, thhe same crop factor would apply. I would recommend the 14-24 F2.8 Nikkor, but if you're on a budget, the next best would be one of the Tamron or Sigma 17-50 F2.8s; I think those are pretty affordable. I've heard some good things about the Sigma.