Considering a Sony SLR...

[dr4gon]

1. Lens creep - as I understand this is very annoying?
2. Picture quality - I've read that the Tamron is VERY soft around the edges and at 6,3 they don't let in a lot of light?

Please try to guide me and help me make an informed dissision - would like to hear from owners of these lenses as well.....

Thanks a lot.

Carsten

1. Yes, very.
2. Yes it is soft on the long end, wide open and it has a very small aperture at 6.3

btw, the 270mm VC is not a Sony mount lens. The only option there is the 18-250mm.

[DonSchap]

You don't need VC ... it would just screw things up. It was designed for camera manufacturers that apparently didn't figure out that in-the-camera-body stabilization might be kind of handy, too.

[Peekayoh]

.........Hmm, not quite getting this, does this have a positive effect on the IQ ?

Undoubtably; the smaller pixel is a key reason for the image quality difference, especially in terms of noise and dynamic range.
So far as I know the DSC-W300 has a receptor size of 1.8 microns compared to 6 microns for the A330. That's 11 times the area (Squaring up) in favour of the DSLR and makes a huge difference when viewed at a similar size.

[calun]

Hi guys

DonSchap: Thanks for pointing out the VC thing!
Peekayoh: Thanks for explaining the pixelsize difference!
Dr4gon: Thanks for your answers.

A few followups:

1. If 6,3 is a bad aperture, what would be called acceptable at 250/270mm ?
2. Are the two lenses mentioned unusable in bad lighting conditions ?
3. Do you have any other suggestions as to lenses (maybe not made ny Sony) ?
4. Or fourth and worst, am I not getting around having two lenses ?

Thanks again.

Carsten

[Peekayoh]

...... 1. If 6,3 is a bad aperture, what would be called acceptable at 250/270mm ? ........ Carsten

You need to understand how increasing focal length affects shutter speed and also the relationship between aperture and shutter speeds.
At longer focal lengths, like 250mm, any camera movement is significantly magnified. Conventional wisdom says that shutter speed needs to be at least the reciprocal of focal length (i.e. for 250mm you need a 1/250th shutter). The AS feature improves things so you may manage 1/125th sec, who knows?.

Look at this diagram which is a graphical representation (to scale) of aperture size.



F4 is exacly half the size of f2.8 and so lets in half the light; that means you need to double the shutter speed to let in the same amount of light.
The same goes for F5.6 / f4.
You will easily see that f5.6 allows one quarter of the light of f2.8 and therefore needs 4 times the shutter duration to maintain the same exposure (f6.3 is another 1/3rd of a stop smaller).

If 1/200th sec is needed for correct exposure at f2.8, then you need 1/100th sec at f4 and 1/50th sec at f5.6. That means that, for a 250mm lens, not only will you have camera shake, any moving subjects (kids) will have motion blur. The bottom line is that you're going to need the Sun in the sky unless you use flash or take landscapes off a tripod.

That doesn't mean the lens is hopeless, just limited.

But then, why would you buy an SLR and not change lenses? There's no way a superzoom can have the quality of smaller zooms or a Prime Lens.

[DonSchap]

Peter ... I have to admit, the all-in-one lens is the "handiest" in my rack. Yes, you need to have a decent flash unit to support it (not that cheap HVL-F20AM they are releasing. I am talking about a '42 or a '58 - preferrably the latter), but it is the most convenient lens, on the fly, I have ever had. I call it the "grab and go" ... for situations like when the fire engines rip down the street and the area is going up in smoke ... you want it all ... and you want it NOW! Or pound down the streets of your vacation wonderland, where you simply do not have the ability to carry large mounts of photographic hardware. Just the flash in your pocket and the camera/lens slung around your shoulder. You're not doing an architectural journal, just vacation shots to say, "Yeah ... I've been there."

It really has a place ... for a struggling mother, with kids running to and fro. It basically turns your DSLR into a "P&S" that you a very familiar with. You can one-hand shoot it and not have to worry about tossing lenses off and on.

Now ... to be fair to your photography, you should have a pair of regular lenses to back it up ... to keep from getting complacent. Those would probably be the the 17-50mm f/2.8 and the 70-200mm f/2.8.

Once again, one of the sacrifices with this lens is that you should add a good flash to it, to make it work throughout its range, as it gets kind of dark past 135mm, not just at 200mm!

[Peekayoh]

Don, you'll get no argument from me on the versatility of that 18-200mm.
I just question Carsten's philosophy on being reluctant to swap lens'.
I guess he'll change his mind in due course.

[DWessel]

Wow guys, everyone's been busy on this thread! How did I miss it ... oh, yeh ... work .

All that I would add for now is that, while a 1 size fits all lens (and not wanting to have to change lenses) is a desire you have, there is no such animal.

I was recently in your situation ... shooting with a fixed lens zoom (no in-body) stabilzation) and looking to upgrade to a DSLR. Since I had no lens collection, I was not brand committed and looked at all of the 3 majors (Canon, Nikon and Sony). I found that each camera brand and each lens line-up/type had its positives and negatives. It ultimately comes down to how much you want to spend and what features are most important for you overall. Then make the compromises ... or plan on making it a long term proposition of continual growth.

Cameras:
Canon seems to have better noise control with its cameras and an extensive lens line-up, but I've read alot about focusing problems and you're generally looking at much higher costs overall, especially when you're looking at IS lenses.

Nikon (which you indicated you don't care for) is touted for its color clarity and also has an extensive lens line-up, but also at a generally higher cost.

Sony has the in-body SSS stabilization which opens a host of older less expensive lens possibilities in addition to new Sony/Tamron/Sigma lens choices. The Sony's generally have higher MP compared to equivalent model Canon and Nikons which can be a plus if you're planning on making large blow-ups. And, personally, I found the Sonys have faster focus in low-light.

Lenses:

I'm all for your idea of having a single main lens on your camera. But, as much as you may detest the idea of changing out lenses, I think you will soon find situations where you will be like ... damn, if only I had "..." (insert "a macro lens" "a wider lens" "a faster lens" "a longer lenght zoom")

If you go with Sony, I would recommend considering Tamron over the kit lenses. If your goal is a single lens and you don't plan on doing much natural low light photography, the Tamron 18 - 250mm f/3.5-f/6.3 XR DI-II LD Aspherical (IF) (about $500 US) or similar lens will probably suit you well. If you're going to be natural low light photography, I think you would do well to with two of the f/2.8 Tamron zooms (Tamron SP 28-75mm f/2.8 XR Di LD-IF and Tamron 70-200mm f/2.8 DI LD (IF) Macro) which cover a great deal of territory for about $1100 US with decent quality optics and low-light capability.

No matter what, you're looking at compromises with any lens ... e.g. a fast prime (50 mm f/1.4) will generally give you a crisper image than a less fast zoom (28-70 mm f/2.8) whereas the zoom lens allows you to adjust your composition by zooming while a prime requires you to do the zooming by physically moving backwards and forwards. Sony's in-body SSS can be an enormous plus in hand-held low light situations where you can't set up a tripod, but it can only do so much when you are using a long lens like the Tamron 70-200mm which is about 7" long (about 18cm) compared to a shorter lens like the Sony 50mm f/1.4 which is about 3" long (about 8cm).

For myself, I like shooting natural and low-light. I opted to buck up, skip the APSC sized sensor cameras and splurged for the a900. I've been loving it ever since. And with the Sony 50mm f/1.4 on it, I've even been able to take reasonably crisp hand-held night shots.

[calun]

You need to understand how increasing focal length affects shutter speed and also the relationship between aperture and shutter speeds. At longer focal lengths, like 250mm, any camera movement is significantly magnified. Conventional wisdom says that shutter speed needs to be at least the reciprocal of focal length (i.e. for 250mm you need a 1/250th shutter). The AS feature improves things so you may manage 1/125th sec, who knows?.

F4 is exacly half the size of f2.8 and so lets in half the light; that means you need to double the shutter speed to let in the same amount of light.
The same goes for F5.6 / f4. You will easily see that f5.6 allows one quarter of the light of f2.8 and therefore needs 4 times the shutter duration to maintain the same exposure (f6.3 is another 1/3rd of a stop smaller).

If 1/200th sec is needed for correct exposure at f2.8, then you need 1/100th sec at f4 and 1/50th sec at f5.6. That means that, for a 250mm lens, not only will you have camera shake, any moving subjects (kids) will have motion blur. The bottom line is that you're going to need the Sun in the sky unless you use flash or take landscapes off a tripod.

Great explanation, thanks for this!

That doesn't mean the lens is hopeless, just limited. But then, why would you buy an SLR and not change lenses? There's no way a superzoom can have the quality of smaller zooms or a Prime Lens.

I get the point, but still, even with an amateur/get-up-and-go lense, the pictures are still much more crisp, let in more light and the depth is MUCH better than in a compact...

Don, you'll get no argument from me on the versatility of that 18-200mm. I just question Carsten's philosophy on being reluctant to swap lens'. I guess he'll change his mind in due course.

I don't know what to say, but I couldn't help laughing when I read this. It seems that you have been dealing with guys like me before

But, there's some truth to it; I went to a party last night, my friend brought his new 30mm f/1,4 lense, amazing pictures, and the amount of light it lets in, fantastic. So you're probably right, I will be getting more lenses down the line, but since this will be my first DSLR and I don't know for sure where I'm heading, I also need to look at the economics of things...

But I sure appreciate all of you guys and the amount of help I'm getting!

Carsten

[calun]

Wow guys, everyone's been busy on this thread! How did I miss it ... oh, yeh ... work .

All that I would add for now is that, while a 1 size fits all lens (and not wanting to have to change lenses) is a desire you have, there is no such animal...........

Thanks for your extensive post!

As you might see from my last post, I'm allready convinced that you (and everybody else in here ) are right, I need more lenses.

Friday this week I'm going to the international airshow in Paris, France, and allready I'm worried about having a DSLR come along, and with more lenses...ohno... But I don't know what else to do, I want to move up to better images and more advanced shooting options.

Carsten