Why is a fast lens preferable over (18-200) VR?

In my quest to find more and more information before committing myself to the 18-200VR lens (the more you read, the more confused you are ), I have read at many places that it is preferable to have a fast lens than VR. Could somebody please throw more light on this?

First of all, I am relatively new and just bought a D50 one month back, but have been doing some film SLR shooting few years back.

I have read that the 18-200VR gives you a 4 stops advantage. My understanding is as follows - Suppose I have a 50mm f1.8 lens and I could take a photo at f1.8, 1/100s with it. If I am using the 18-200VR at 50mm, I will have to use say f4.5, 1/15s, which I still will be able to do handheld. Of course the dof with 18-200VR will be lot more than the 50mm prime. Also if there is any movement in the image, it will show in the photo with the 18-200VR because the shutter speed is lot less. So there are two reasons that I can see - dof and motion blur.

Are these two things really really important? Is the difference in dof between f2.8 and f4.5 is so much? Are there any other advantages of fast primes (or zooms) over VR? Isn't it that I can go at much more lower shutter speeds than a fast lens might allow even with its widest aperture?

I think it's important for sports maybe but not for general purpose photography e.g. travel and family and portraits. In fact I like to take low light photos with motion blur to indicate movement.

The concern is not about 50mm 1.8 because it can be had for approx. 100USD, but if I think about other fast zooms, they are simply not affordable for me, neither am I willing to carry the bulk of these lenses.

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Kiran
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You seem to have a good understanding of how vr works versus a 'fast' lens. The question you need to ask is with the type of photography you want you do which lens is better for you? I have the 18-200 now as my daily lens and do 90% of my shooting with it (other than macro or very long zoom) and find it works very well esp. with the vr function indoors when I don't want to use flash. As long as you understand the few design compromises that have been made with an 11x zoom lens. For sports etc. a lens such as a 70-200 2.8 is a great lens 9 the Nikon vr is one of the best but also very expensive. People rave about using it at weddings etc not only because it's fast but also because of the combined vr function. I made the decision to go with one lens if at all possible for most of my shooting. It was the sigma 18-125 until the 18-200vr came out. I'm pleased with it as it also allows low light use whe you realize how vr works and its limitations with relation to subject movement. Other posters here also have commented on the same lens - a search gives great results including some fantastic pictures. Not heading towards the pro venue I can trade portability for ultimate image quality by using 1 lens rather than carrying a bunch of very good but heavy and expensive lenses around.

Hi,

That is a very good reply to which I would just add one point. I have the 18-200 VR and a 50/f1.4. On the one hand, the VR will compensate for camera shake and allow photos to be taken in lower light levels where the subject is static or nearly static. On the other for a given ISO setting, a fast lens, which lets in more light, will allow a faster shutter speed for a similar light level and it is this that enables one to take subjects that have more motion without blur. I often, simplistically (and I wait for others to comment on this), think of the VR as compensating for camera shake in lower light levels, whereas a faster lens is better able to cope with subjects in motion in similar ISO/light level conditions.

Hope that helps.

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Jon

http://jules7.smugmug.com/

You obviously understand it very well. I think that fast glass , like the 50/1.8 is disadvantaged vz the vr if you need it for low light - or indoors static things - when you need to open up the apperture to around 2 or lower , here the vr is much better, and dont forget that the 50/1.8 is quite soft at f1.8 , I had to dial to f2.8 at leas to get sharp images or even more for sharpness edge to edge . . I find I usually prefer deep DOF and here and there When I do want small DOF i use my 50/1.4 or 105/2.8

to complemen my 18-200VR . If I were top do sports and ohe very fast things I would probably go for a faster zoom such as the heavy hefty expensive 70-200VR .

Therer is another reason , at least it was in the past , of useing fast zooms , as their over all IQ was superior , which probably also today but luckily we have fantasice PP. tools to easilly correc waht was almost impossible just a few years back .
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avis
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Nikon D70, 50/1.4, 105/2.8, 18-200VR SB600, SB800
Gitzo 1228, and 1226 ,

I now have the 18-200 and use it also 90% of the time,
but for portraits I take my 150 2.8 Sigma, for one reason
only: DOF at 2.8. But that's a matter of taste maybe.

I find shallow DOF very important in my pictures,
even at macro.....

Wannes
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...and a couple more:

A fast lens will give you:

• A Brighter image in the viewfinder

This may help with composition etc

• Possibly, better autofocus as there's more light for the AF to work with

Other than that, I think you're actually looking at two issues here:

i) A Fast lens vs an Image Stabilised one

ii) Having a single versatile flexible general solution (eg the 18-200VR) vs using several lenses that may offer you more quality/features at the expense of less convenience, more weight etc.

Sorry, I don't have the 18-200 (a local shop in the UK has a waiting list of over 300 people!). However I've moved from a digicam that had an image stabilised 18-200 lens to a D50 with one F2.8 zoom and 2x F2.8 primes. The curent setup is certainly less convenient, but so far, I'm loving it and the image quality I can now get.

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Colin Malsingh
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Once you get a taste of what f/2.8 does, you'll hardly want to go back. I was on the Atlantic City boardwalk after sunset last week and I could hardly do anything with my zoom @ 5.6. I ended up putting it back in my bag & used my macro lens 105 mm @ 2.8 instead.

That's what made me decide to purchase the 70-200 VR 2.8 yesterday. Weight trade-off isn't so bad since I'll be leaving my 105mm VR + 70-300mm home now (macro lens goes back to macro duty only ....).

Big minus to fast glass is that it's heavy and bulky. But then again, I think a D-SLR is heavy and bulky in the first place anyways.

if you wanted one, Jessops web site appears to have the 18-200VR- I ordered mine on Wed eve, got it this morning.
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DeeJayBee

I have only rented the 18-200 on one occasionand had some success with, but also some failures...

Anyhow, I surmise that the vr function also helps with hand-holding at average speeds and even faster speeds all but guaranteeing good results.
Am I correct here?
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Photo Bill

One of the other posts stated it very well. The VR will let you take a shot in low light when things are not moving around since the apperture is not as open compared to the fast glass, so your are facing motion blur from the subjects. With fast lenses you can kick up the shutter speed since the aperture is more open, allowing more light in. Since the shutter can be released faster you are more likely to stop the motion of the subject. The ultimate combo is fast lens with VR, now you can stop the motion and the VR will minimize the motion you are introducing camera shake. On wide angle lenses you can slow the shutter and not be as affected by camera shake, where as on telephotos it is quite noticable.

One thing that has helped me come to terms with all this is this:

Each F-stop will double or half the amount of light coming in. ISO same thing 200 ISO is twice as sensitive to light as 100 ISO, Shutters speed is the same 1/60 will let in twice the light as 1/120.

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-Michael
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avi said:

Therer is another reason , at least it was in the past , of useing
fast zooms , as their over all IQ was superior , which probably
also today but luckily we have fantasice PP. tools to easilly
correc waht was almost impossible just a few years back .

Click to expand...

Is that the same thing though? I don't know.. I've never liked the appearance of a softer image that was sharpened via PP vs. an image that was already very sharp straight out of the camera. Not only are the sharpening effects noticeable, they often detract from the overall quality of some images due to some of the various negative effects from the sharpening process.

I like the 2.8 because

1) I could use it in cases with VR wouldn't work. Such as taking picture from the plane, I could bring it down to 2.8 to give me the high shutter speed I need

2) 2.8 gives me better DOF and Borken (spelling?)

I would like to get 18-200VR if it didn't have to cost me 800 bucks for it. I would pay once supply keep up and get it for 699 or less.

Now if the 18-200 VR comes in 2.8, I wouldn't mind paying up to 2k for it!! Now that is one ideal walk about lens!

Of course if they do that, why by the 70-200 VR 2.8 and 17-55 2.8 combo right?

hahahahaah

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-Michael
Just take the picture =)
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17-55 VRII f/2.8 I would kill for. City night photos w/o tripod.

Shiat, I'm starting to envy Sony users who will get VR on all their lenses

Cause things move.

Larry

that is the paradox here, as the lens gets bigger and heavier (2.8) and more difficult to hold, especially in situations where the abscence of light, the camera requires even more stability,

you might have to convert an old two wheeled golf bag carrier into a sort of mobile tripod and ....I'm getting carried away here but that is why I switched to primes mostly.

My 80-200 2.8 is heavy after a couple of hours carrying around so I use it mostly when I'll be in a fixed position for awhile.

but smaller primes are portable and my shooting style always is within the 40-60mm range.

P. Bear

VR can help in shooting handheld at longer speed for those subjects that are relatively stationary. But to freeze action, you do need fast lens. Then there is an added advantage of being able to control depth of field a little better with a fast lens.

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Speed is significant and interesting but accuracy is downright fascinating
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Pradipta Dutta said:

Then there is an added advantage of being able to control depth of field a little better with a fast lens.

Click to expand...

True, but what's in and out of focus is also tied into the degree of magnification of a subject and distance between the in-focus subject and the surrounding foreground and background.

Also, it's not that difficult to add selective blur to a photograph, something not possible before we had the ability to digitize photographs.

I can recall telling myself, a long time ago, that I would never purchase a "slow" zoom lens. Of course, I was shooting film rated at ASA 50. Now I have access to VR and much higher ISOs, smarter speedlights, plus Photoshop, GraphicConverter, Nikon Capture, etc., not to mention Noise Ninja (and I'm not a wedding or sports photographer - if I were, I'd probably have a different set of optics).

Of course, it's fun to own complicated and sophisticated technology, even if it doesn't make us money. That is one reason why people who don't necessarily need lenses with large f/stops, still want to have these wonderful beasts, including me.

Photo made w/ 18-200mm VR



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...The reason (IMHO) a lens is considered "fast", is due to it's ability to focus quickly.

A 70-200mm f/2.8 @ 200mm is different than a 55-200mm f/4.5.6 @ 200mm...

1st .. Each lens focuses using it's widest aperture, ie. 2.8 -vs- 5.6.
2nd .. The wider the aperture the more light that reaches the viewfinder.
3rd .. The extra light creates contrast for extra focusing speed, ie. "fast"

This speed may not make a difference out in the sun, but try using the 55-200mm indoors with available light. You will need a flash. Using the 70-200mm, you may be able to get by without the flash.

If you have a f/1.4 lens, all the better.

VR is a different issue altogether. It's purpose is to 'stabalize' the image, but only after VR has 'kicked" in. You first have to let the VR system lock onto the subject. Hence, the faster you can lock on, without the lens 'hunting', the faster VR can start to work.

So, the only advantage a 'slow' VR lens has over a 'fast' non-VR lens is the VR, but only after focusing has taken place.

Remember the 55-200mm zoom, being used in dim light. Even using a flash, the lens has to focus first, but the flash could go off before VR has a chance to work.

Again, IMHO.

Nikon-Kid

it has nothing to do with the speed at which a lens focuses. There are many 'fast' primes that are manual focus. The term was used long before AF was introduced.

Nikon-Kid said:

...The reason (IMHO) a lens is considered "fast", is due to it's
ability to focus quickly.

Click to expand...

Nikon-Kid said:

Nikon-Kid

Click to expand...

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