Which zoom? Nikkor/Tamron

[mechsympathy]

I'm looking for a zoom for my D70 and I'm tossing up between the 70-300 Nikkor D lens and a 28-300 Tamron lens, they're the same price (£250). I'm tempted by the Tamron because it'll be more versatile, but I'm not sure how much quality will be lost. Does anyone here own one??

[Mad Dave]

I would go for the Nikkor if the aperture size (f stop) is the same. You don't really need the 28mm end of the Tamron as you already have the (IMHO v. good) 18-70mm Nikkor.

What the 'f' value on them?

Dave

[mechsympathy]

The Nikkor is f4/5.6 AF, and the Tamron is f/3.5-6.3 XR DI

(And another numpty question. f refers to focal length (AFAIK), but what is the relevance of the different position of the slash? Or is it just a typo on the website?)

[luca brazzi]

Nikkor 70-300 f4/5.6 AF

Means at 70mm, the max aperture is f4, and at 300mm, the max aperture is f5.6
-----------------------------

Tamron 28-300 f/3.5-6.3 XR DI
Means at 28mm, the max aperture is f3.5, and at 300mm, the max aperture is f6.3

Tamron's xrdi lenses are excellent quality. But have a read of some owner reviews of this particular lens....here:
www.fredmiranda.com/reviews/showproduct.php?product=247&sort=7&cat=43&page=1

Hope this helps,
LB

[simpo two]

mechsympathy said:

(And another numpty question. f refers to focal length (AFAIK), but what is the relevance of the different position of the slash? Or is it just a typo on the website?)

f is actually aperture (the hole). For fixed aperture lenses the slash is optional IMHO, although it's also getting used to denote an aperture range, as you've seen.

If I was looking for an indy lens with monster range, I'd be very tempted by this new Sigma:

www.sigma-imaging-uk.com/lenses/dclenses/18-200mm.htm

However, generally the bigger the zoom ratio, the smaller the aperture - so worse low-light preformance - it's a compromise.

>> Edited by simpo two on Tuesday 22 March 11:16

[Mad Dave]

The lower the number, the bigger the aperture, so therefore the better the lowlight performance (as it can get in more light at a time).

[Prof Higgins]

Might have a good example of the Tamron for sale, bought 5 months ago for my wife as an all purpose lens but think in all reality she will stick with using her Ixus as is handbag friendly. Think the lens has shot about 100 pics max.

Certainly some pics have shown a bit of softness at the full 300mm end when shooting wide open, but then the advantages are that you can walk out the house with 1 lens and 1 camera and know that you have a lens for pretty much all occassions.

Mail me via profile if interested, am looking at about £150 for it.

Sinclair

[HankScorpio]

Not sure how it is on the Tamron but check whether the focal length is "35mm equivalent" or if it's what it will actually be on a D70.
I did read some companies are marketing the focal length in different ways.
The Nikkor would get you 400mm equivalent on the D70 but if the Tamron is a true value, you'll be getting 300mm.

[simpo two]

HankScorpio said:

The Nikkor would get you 400mm equivalent on the D70 but if the Tamron is a true value, you'll be getting 300mm.

Nope, 300mm is always 300mm: the focal length of a lens can't change depending on the camera you attach it to. The 'crop factor' is simply a mental adjustment because a 300mm lens on a D70 gives the same area of view as a 450mm on a 35mm film SLR.

So, if you're used to the wide angle that you get from a 28mm lens on a film SLR, you'll need an 18mm lens to get the same effect on a D70.

>> Edited by simpo two on Tuesday 22 March 19:05

[HankScorpio]

I stand corrected.
Field of view, not focal length.

Handy little graphic calculator on here:
www.steves-digicams.com/digi_dictionary.html

Under FOV (Only works in popup from that page). Also gives 35mm equivalent.

Fascinating really...
300mm lens on 35 mm camera/sensor gives FoV of 6.52 degrees (couldn't do notation properly) or 11.96 meters wide, on a D70 it's 4.31 degrees and 7.88 meters.

The little graphic makes it very clear.

[mechsympathy]

But...

As you say at 100m a 35mm camera/sensor gives a FoV of 11.96m and a D70 gives one of 7.88m then on the same size print that is an increase in zoom...

I guess effectively it's a digital zoom, rather than optical but that effect will be offset by the relative increase in pixels. I.e. a full size sensor with 6Mpixels will have a lower density compared to a 2/3 size sensor. It would be like cropping a 9Mpixel picture by a third.

Does that make sense


>>>>Prof Higgins, thanks for the offer I am having a think. Especially as I can't find the Nikon lens in stock anywhere.

>> Edited by mechsympathy on Wednesday 23 March 08:35