SLR lens - zoom

richieg

I am considering buying my first digital SLR and taking an evening course on digital photography but I have a question in relation to lens and zoom is specified. I am looking at the Nikon D40 and a 35-200mm additional lens (kit offer in Argos). Coming from point and shoot cameras its pretty clear how much zoom you have ie 3x or 10x etc. My question is how do you know what zoom you get from SLR lens?

Probably simple question.

Stephen

The higher the number of millimetres, the longer the zoom. I don't know of any way to directly convert from mm to 'x'. I use a Nikon D50 with a combination of the kit 18-55mm lens and a Sigma 70-300mm lens. I don't miss the 15mm in the middle that I'm missing

With digital SLR's you also get some extra zoom 'for free' due to the smaller size of the typical sensor in a digital camera compared to a frame of 35mm film - you can normally multiply the focal length of your lens by about 1.5 or 1.6 to calculate this. The down side of this is that the wide angle end of your zoom is also multiplied by the same factor, so your 18mm (for example) wide end would really be about 27mm.

rabbitinlights

Yup, Stephen is spot on, Forget about the 10X stuff:

The lower the number the wider the shot.

PaulieC

to get the zoom factor (10x, 3x) on a lens, divide the tele end by the wide end e.g. if you have a 70-300 lens, divide 300/70 and you get 4.2 (or something like that), therefore it's a 4.2x lens. However, as mentioned above, that's pretty useless information as it doesn't tell you that the wide end of the lens is still 70mm (or 105mm on a 1.5 Crop D50/40)

mathias

For landscapes etc. you want to start pretty low , I believe 10mm is the lowest for a standard lens.

A good single lens to get would have a range of say , 17 to 85 , this covers the most common usage , 17 is quite good for landscapes and 85 is a reasonable zoom.

Most kit lens are not great and if you can , buy the body only and a decent all round lens. Sigma and Tamron are well worth looking at if the prices of the Manufacturers lens horrify you.

For SLRs , its better to cover the range needed with multiple lens , thats the beauty of an SLR after all.
So for super wide , a 10 to 20 mm , for common usage , a 17 to 85mm , and a 70 - 300m for the high zoom end.

And yes the zoom is calculated by dividing the high number by the low.

There are single lens that have 10 or 12 x zoom , but picture quality as a rule suffers !!

Heres a good site for lens reviews and sample pictures ,
http://www.fredmiranda.com/reviews/

Zillah

55mm is about what the human eye will see. Higher means its more zoomed in, lower means its wider. Just try out different lenses and you'll get a feel for what they do.

35-200 will cover pretty much anything you'd need it to do. If you were trying to get big landscape shots then lower than 35 might be worth it. If you were getting wildlife or sports then longer than 200 might be worth it.