Which Zoom Lens(es)?

[Netvyper]

Hi folks;

I've got a 350d, taken a good few shots now; so im starting to get the hang of it; and starting to think about expanding my lens collection.

I presently have the 18-55 kit lens, and a 70-300m Tamron. I tend to find myself sticking to the 18-55 except in fairly specific circumstances; primarily because it invariably involves setting up the tripod; anything above about 150mm is incredibly difficult to handhold.

What are peoples opinions on the Canon 55-200mm F4-5.6 IS? Is the IQ higher than the Tamron, as well as being easier to hold?

If I get this lens, then I'd a shorter lens too, and while the 18-55mm f3.5-5.6 IS is tempting; the Sigma 17-70mm F2.8-4.5 is probably more so; Perhaps even a Sigma 18-50mm f2.8.

My other option is a Tamron 28-300mm VC Di, the idea being that its the only lens I need to take with me for 90% of trips; and perhaps grab an ultra-wide 10-20mm or similar for the really wide shots. The downside is the 3.5-6.3 apature; this is a bit slow at the long end; even more so than my current Tamron, and of course being double the price of the aformentioned lenses.

I would really appreciate any comments from people who've used these or similar lenses.

 

[Scam]

Why are you having difficulty hand-holding at over 150mm?

 

[Netvyper]

I dont know; perhaps I just dont have very steady hands or maybe a poor technique
might be that its over 200mm I struggle to hand hold it, I cant remember exactly; and owing to my main PC being offline atm I cant check back through my old shots. Essentially; the only shots i've taken with the 70-300 that I like; are ones where i've had static subjects & setup the tripod.

 

[Amoeba]

One rule of thumb for shooting long focal lengths is to make sure the shutter speed is at least that of the length of the lens. Ie if you have a 200mm lens you will want at least 1/200th shutter to reduce chance of motion blur.

Just something to keep in mind if you are having difficulty .

 

[Netvyper]

One rule of thumb for shooting long focal lengths is to make sure the shutter speed is at least that of the length of the lens. Ie if you have a 200mm lens you will want at least 1/200th shutter to reduce chance of motion blur.

Just something to keep in mind if you are having difficulty .

Will have to check & see what shutter speeds i've been using; thanks for the tip

 

[Scam]

Just to clarify the shutter speed should be 1/focal length (not necessarily the length of the lens!). i.e. if you're zoomed at 50mm you'll get away with 1/50th, but if you're zoomed at 300mm you should be using anything shorter than 1/300th. Just up the ISO if you cant get a shutter speed short enough.

 

[D.P.]

One rule of thumb for shooting long focal lengths is to make sure the shutter speed is at least that of the length of the lens. Ie if you have a 200mm lens you will want at least 1/200th shutter to reduce chance of motion blur.

Just something to keep in mind if you are having difficulty .

Zou will also have to take into account the crop factor. So on most DSLR a 200mm lens will require 1/300s for the average person.At 300mm you need 450th/s. But this is a rule of thumb, not a mathematical result based on the physics of the lens. Just an observation of most people hand-holding.

People with steady hands can get away with far less, parkinsons people could add a factor 2-3X. One thing to mote is that at longer focal lengths technique becomes more important. This is where most people fail as they will just point the lens at the subject and click.

 

[Hodders]

Also a couple of the lenses mentioned had IS - this will certainly help with hand held shots at longer focal lengths.

 

[Nicos Rex]

Whilst the guidelines about choosing a suitable shutter speed are correct as far as they go, they assume a modicum of correct technique.

Without going into too much detail this includes your stance, arm position, how the camera is held, and perhaps most importantly of all how you release the shutter.

Stabbing at the shutter release and/or pulling your finger away as soon as you have pressed it are in my experience the most common causes of camera shake - this is actually a really good thing because it is also the easiest error to correct.

 

[Amoeba]

Just to clarify the shutter speed should be 1/focal length (not necessarily the length of the lens!). i.e. if you're zoomed at 50mm you'll get away with 1/50th, but if you're zoomed at 300mm you should be using anything shorter than 1/300th. Just up the ISO if you cant get a shutter speed short enough.

Hehehe this is what I meant .

 

[Mr Jones]

I personally have an 18-55mm IS and a 55-250mm IS. As mentioned by Scam, the rule of thumb is still required for tact sharp photos when it comes to long zooms, the 55-250mm IS is great - because of the extra stop down I can do (Canon says 3) I usually don't stop down too much.

I almost got the 28-250mm VC but went with the 55-250mm IS due to all the photos I've seen on forums, flickr, in comparison to the 28-250mm. It looks so much sharper.

However! Having a 2 lens pairing can be a pain as when you see a longer range shot, you'll need to switch quickly before it's too late e.t.c where as the 28-250mm is great for whatever the occasion is. These ultra zoom lens are much considered as "Visiting Disneyland Lens", useful for whatever the occasion.

So have a think before you decide. I'm selling away my 55-250mm IS after a few weeks use, I realise I shoot a lot between 18 to 80ish, so crave a sharper lens in that range

 

[Amoeba]

Zou will also have to take into account the crop factor. So on most DSLR a 200mm lens will require 1/300s for the average person.At 300mm you need 450th/s.

Would the crop factor actually make any difference? The image circle projected onto the sensor will be the same (ie shaky or not!) whatever size the sensor is .

 

[Mr Jones]

Would the crop factor actually make any difference? The image circle projected onto the sensor will be the same (ie shaky or not!) whatever size the sensor is .

The way the maths works out is the actual focus length the sensor receives, as the crop factor of say 1.5x, the sensor is seeing 300mm as 450mm, therefore shooting at around 1/300 will likely result in camera shake if not steady, compared to say 1/450mm.

 

[EsaT]

Would the crop factor actually make any difference? The image circle projected onto the sensor will be the same (ie shaky or not!) whatever size the sensor is .

Yes it makes difference because with same resolution pixels are smaller in smaller sensor meaning smaller movement of projected image is enough to move "light ray" coming from one point/detail in FOV to adjacent pixel and blur image.
As proof in small pocket cams actual focal length typically starts from 5mm and in ultra zooms goes to 50mm but you've still had to use rule of thumb shutter speed related to effective/35mm equal focal length.

 

[D.P.]

Would the crop factor actually make any difference? The image circle projected onto the sensor will be the same (ie shaky or not!) whatever size the sensor is .

Yes, surprisingly no one tells you this and as a begginer I followed 1/lens FL and often suffered from soft images. One day I was working out the physics and realized I would have to take into account the crop factor for the same rule to apply. I since verified this looking online. Since then I have much higher hit rates for keepers.

The other useful thing to think about is your DoF and aperture. As a beginner I would always push for the smallest aperture for landscapes, going down to F/22 etc. In actual fact, you very, very, very rarely need such an aperture, and will keep to F/11. The advantage of this is that the lens is far sharper at F/11 than smaller apertures. And the higher the resolution of your sensor, the larger the smallest aperture you cna use to maintain the same sharpness. I guess this roughly goes along with doubling the pixel density will drop the smallest aperture by 1 stop.