Focusing problem with a 0.45x conversion lens

[koocha]

Hi all, first time poster! Please go easy on me!

I've got a Sony A300 with a Tamron 18-200mm lens. I got a 0.45x converter lens to help me get wider shots but my lens won't focus with it on. It tries, but it physically can't focus on it.

Is there anything I can do, maybe with some kind of stepping filter?

Thanks for any help

Tim

[StuG]

:crigon_04 To another Sony user

Sorry don't have a 0.45x converter so I can't really help, but welcome anyway

[mogawowo]

whats it like manual focusing?

[lostmysnorkel]

Very often, the loss of light through the lens with a converter added means there isn't enough for the AF to be able to lock on anything.

I know the Nikon SLRs need to be at f4 or wider to AF with a converter.

And this might be a really dumb suggestion, but give the glass in the converter a good clean - it could just be that a fingerprint or summat is confusing the AF.

[koocha]

Hi, thanks for the replies.

The problem isn't that it can't focus as in it's constantly trying to focus, the problem is that the lens physically can't focus because (forgive my level of technical terms) the focusing ring can't spin round as much as it needs to.

It's just a conversion lens that screws onto the end of my normal lens (62mm).

It comes with 2 parts - the 0.45x converter and a macro "filter".

Here's the link to it:

http://cgi.ebay.co.uk/62mm-0-45x-WID...d=p3286.c0.m14

When both are together it focuses fine all through the focal range, but if it's just one one its own (converter or macro filter) it won't focus at all.

Thanks

[lostmysnorkel]

Not sure I understand the problem properly here. But will have a go at explaining what you seem to be doing.

The Macro Lens, usually called a Dioptre, is designed to reduce the minimum focus distance of the lens. This allows you to get the camera much closer to the subject than would normally be possible and therefore, take 'close-ups' from, well, much closer up!

The converter widens the angle-of-view of the lens, generally, the wider the lens, the shorter the minimum focus distance is.

If, as you say, the lens is trying to focus but doesn't have the range - I would try getting closer to the subject.

If the camera can lock on without the attachment, but can't from the same distance with it, then you need to get closer.

I know with my +4 Dioptre attached, I need to be within centimeters of the subject for it to focus, down to a matter of millimeters sometimes.

[koocha]

Thanks for the detailed reply.

I've tried the lens again to no avail.

I had the macro portion of it working sucessfully -it will focus but i need to be within milimeters of a certain point for it to work.

The 0.45 converter lens doesn't work though. You can see through the viewfinder it's trying to focus but the focusing ring on the lens physically won't spin round enough. It's the same for close things and when trying to focus to infinity.

The seller has agreed to a refund though, so I'll get my money back.

Seems the cheap option for wide angles isn't the way to go. Expensive lens here I come!

Thanks for all your help