The mine field that is............lenses!

M

minimadgriff

Messages
201
Name
Ben
Edit My Images
Yes
Evening all, NEWBIE QUESTION ALERT!!!!!

Lenses, they confuse the hell out of me! So many different types but why? Which ones are essential? What makes a good lens? What ones should you definatley have etc etc? Does one not cover most basis?

I have a A350 with 18-200 lens and mostly take shots of cars and motorsport, but what other lens(s) would be good to have in my bag for these types of shot?

I keep seeing 50mm lenses mentioned and also beer can? What are so good about these and what are they good for?

Any info and help greatfully recieved! :thumbs:

Ben
 
That's a very big question!

The main thing is focal length range, and you have got most popular focal lengths from modest wide-angle to medium telephoto covered with your 18-200mm. Excellent walkabout range. What is less good there is that it will not be as sharp as lenses with less ambitious range, and it will also suffer from other optical shortcomings like chromatic aberration (colour fringing) distortion (straight lenses may be curved towards the edges of the frame) and vingetting (darkened corners).

Plus, the lowest f/number will be quite high, around f/4-5.6 typically, whereas alternative zooms will go down to f/2.8, and prime lenses (fixed focal length) can go down to f/1.8 or f/1.4 - such as the 'nifty-fifty' 50mm f/1.8. Low f/numbers gather more light for shooting in darker conditions, and also deliver much shallower depth of field - the zone of sharpness in a picture that you can control for creative effect.

Broad zoom range and low f/number tend to be mutually exclusive - you won't find an 18-200mm f/2.8 for example. It would be massive, very expensive, and not very sharp.

Apart from optical quality, you pay a lot more for mechanical quality and robustness, weather-proofing etc - eg the legendary Canon L lenses. Then there is image stabilisation to consider, lenses designed for crop format cameras (eg your Sony) that tend to be either a little cheaper or have greater range etc, as they are easier to design.

On the more specialist front, there are macro lenses that not only focus very close, but have very high image quality. Or super-telephotos, eg those big white things you see at football matches, that not only have very long focal length (expensive) but also low f/numbers (very expensive).

Lens choice depnds on a mixture of all these factors, depending on what you want to do, what you can afford, and what you want to hump around. Basically, it usually boils down to focal length range and low f/number, plus price. The usual starting point is focal length - eg wide-angles for landscape, telephotos for sport/action/wildlife, and standard 'kit' zooms somewhere inbetween for portraits and general stuff. Then take it from there.
 
minimadgriff said:
I keep seeing 50mm lenses mentioned and also beer can? What are so good about these and what are they good for?
Click to expand...

A 50mm lens is a comparatively cheap, "fast" and good quality choice. It was the "kit lens" of the film era, so there are plenty of secondhand manual focus ones about. Even the cheapest old'un (from other manufacturers) will be ƒ/2.8 and most will be "faster" e.g. ƒ/1.7 so you can use them in dim conditions or to minimize the depth of field for creative effect. Restricting yourself to a single focal length can help develop your creativity. On the other hand, the results from a "normal" focal length such as 50mm get seen a lot, and you may be happier with a fixed focal length "prime" lens that is wider (e.g. 24mm) or longer (e.g. 135mm).

The "beer can" is the Minolta ƒ/4 70-210mm autofocus zoom telephoto lens. It dates back to the mid-1980s and was better than its replacements, so has become sought-after, secondhand. Being Minolta A mount, it fits your Sony (Sony bought Konica-Minolta, and based their designs on the Maxxum/Dynax/Alpha products). The current prices for the lens would seem high to anyone who bought one 5-10 years ago, but they are still seen as good value when compared to the new alternatives.

If you are interested in the older lenses, make sure you buy A mount and not MD. A list of lenses is available here.
 
Thanks for your replies and taking the time to get back to me.

for what I am taking photo's off what would you recommend I get to go with the 18-200 or should I ditch that and get something else? It does seem to lack sharpness of other people pictures I have seen on here? Unless it's me not using it right of course.

This is the spec of my current lens

Lens Specifications

Product Name
DT 18-200mm F3.5-6.3

35mm equivalent focal length when used with APS-C sensor camera
27-300

Lens Groups-Elements
13-15

Angle of View, attached to APS-C-format camera; degrees
76ﾟ-8ﾟ

Aperture Blades
7

Circular Aperture
YES

Min. Aperture
22-40

Min. Focus (shortest distance from image sensor to subject); m
0.45

Max.Magnification
0.27

Filter Diameter; mm
62

Dimension(Max. Diameter x Length); mm
73x85.5

Weight; g
405.0



Thanks

Ben
 
minimadgriff said:
Thanks for your replies and taking the time to get back to me.

for what I am taking photo's off what would you recommend I get to go with the 18-200 or should I ditch that and get something else? It does seem to lack sharpness of other people pictures I have seen on here? Unless it's me not using it right of course.

This is the spec of my current lens

Lens Specifications

<snip>

Ben
Click to expand...

TBH Ben, I'm not sure that too many of your lens' optical shortcomings will be very obvious viewed on screen here. That's not a very demanding test. The differences will be there if you look hard for them, but it's more likely that you are comparing pictures taken in good, contrasty daylight with those shot in conditions less favourable to showing great sharpness. Focus could be a bit off, or maybe you've got some camera shake in there.

Having said that, you would do better splitting your lens into two, say the Sony 16-80 and 70-300. These are quality lenses, and not cheap. Maybe something similar from Sigma or Tamron.

This is where it gets subjective and if I were you, and clearly this is just a personal opinion, I would jump ship now to Canon and get a 7d (great motorsport camera), 17-55 2.8 Canon lens (super sharp, low f/number), plus a 70-300 IS (great value). You would be completely out of equipment excuses then, as well as broke :D But you didn't mention budget!

Do you work for AMD? They do some neat conversions :)
 
you may be right about comparing pictures being taken in better light etc. I was dissapointed with my last lot of pics from a track day but then it was a dull, over cast day with rain too. So not ideal, but then I see other people shots on over cast days and they are a million times better. :shrug: I do suffer with terrible camera shake, any pics I take in the workshop at work for our BTCC blog I have to use my tripod otherwise they are true shockers!

The lenses you mentioned are the ones I keep seeing get mentioned/used so I maybe should look into swapping the one over for two.

Im pretty sure the Sony isn't at fault and its more user error :lol: So I won't be swapping to a Canon or Nikon :p: Especially not at the silly cheap price I paid for the A350 with this lens ;)

I do work for AmD too :thumbs:
 
i would personally get a 70-210 f4 beercan for motorsport, however i dont shoot it so i cant give accurate info, but i believe a telephoto with a wide aperture is best and it tends to be easier using zooms wit this type of photography.
 
You must log in or register to reply here.
Back
Top