I used to have one of these with my old SLR, having just recently purchased a D-SLR I wonder if it's worth investing, looking to fit it to a 70-300mm zoom!

As I remember the pictures were of lower quality, but we are talking 20+ years ago.

Depending upon which brand of camera you have and also what the maximum aperture of your lens is will depend upon what results you get (or even if it will work).

I'm a Canon user and I know that you will lose two stops of light (effectively going from 1/500 sec to 1/125 sec) with the auto focus (and IS if you have it) being retained only if you have a maximum aperture of f2.8 or faster (smaller number) which I doubt your 70-300 does.

It depends on what you are photographing... the image quality is affected and like above you will not have auto focus.

If the lens is a 70-300 f4.5-5.6 and you slap the 2 times converter on, you will get 600mm but only at f11.... very gloomy!

Trying to focus manually at F11 is damn near impossible on all but sunny days and even then you need a fast shutter speed to counteract the camera shake.

I personally found better results by simply enlarging the centre of the image on the computer.

A 600mm canon lens costs thousands

However...

One of the cheapest ways to get a powerful zoom lens is to buy a camera with a long lens built in...

A Panasonic FZ45, FZ48, or FZ100 have 24 optical zoom lenses of very high quality and cost from £250

I just got a Canon SX 40 for £300 it has a 24mm to 840mm , 35 x optical zoom..... it is awesome!

More importantly you "will" obtain sharp pictures from the long end of the zoom!

Canons EF 800mm f5.6 lens costs a cool £10,000!

Don't forget that on a 'cropped' sensor (anything below a full frame / 35mm sensor) you will have a lens multiplier to factor in.

For example:

APS-C (Most Canon, Nikon, etc. cameras below £1500) you can multiple the stated lens focal length by 1.5 or 1.6' (a 50mm lens is equivalent to a 75mm lens on full frame);

Or

4/3's (Four thirds) sensors: multiply by 2 (a 50mm lens is equivalent to a 100mm lens).

It's quite often a good way of getting telephoto extension without the need for extra kit. You just lose out at the wide angle lens and a little of the depth of filed performance (but not in the light gathering abilities). You also get the best quality out of 'poorer' lenses by only using the central section of the glass which is the sharpest part and suffers less from aberrations.

Interesting, I wonder if I can do that on mine, it's only an entry level Nikon D3100?

Then it already has a cropped sensor (DX Format) which effectively makes a 100mm lens equivalent to 150mm (Nikon have a 1.5x multiplier on this sensor) and means that you can make the most of any telephoto lenses you already have.

However, if these are still not getting you close enough to the 'action' then, without spending thousands on quality lenses, there is no other way than physically moving closer.

Just a thought, they used to make mirror lenses which had limitations but were an easy and cheap way of getting much closer to the action for not a lot of weight or money. I make no recommendation on this product or website, I just use it as an example of the thing I am on about.

500mm with 2x doubler = 1000mm with sensor multiplier = 1500mm. That really is rather close...

Hope that helps.

Thanks pal, next question then as the audience is in the know. I want a wireless remote but they all seem to be grossly overpriced, found the equivalent for a Canon 500D for under a tenner......?

Your D3100 does not have any infrared capability, so the usual ML-L3 remote (£5 on Amazon at the mo) won't work. Odd, since the D3000 had this capability.

Is that progress?

Check your manual for compatible accessories (should be towards the rear of the book), but I suspect that you will need a third party combination of corded and wireless of eBay.

I have used almost every lens option on Canon SLR`s for getting really close up then and it depends what you want to get close to

For wildlife and sport you really need bespoke Super telephoto lenses which cost thousands, these will retain Full Autofocus which you need, manual focus is hit and miss .

These enses are only sharp at short subject to lens distances, at long distance they become softer due to atmospheric conditions, air pollution etc.

I have used the Samyang mirror lenses of 600 and 800mm and these are impossible to hand hold and get sharp pictures, even using tripods they are tricky to use, the depth of field is narrow and unless you have a special focussing screen are awkward to focus.

IMHO the best combination is a canon 70-200 f2.8 and a 2x converter, or the 300 f4 with a 2x of 1.4x converter

Best budget is the Sigma 50-500 but this is a heavy lens but sharp

Or, keep your current lens and move to a closer bush

Or, keep your current lens and move to a closer bush

Surely I would need a macro for bush close ups???

Here is a first attempt at the moon last night, happy with the result. :yes: