Problem with 70-300 lens

[abacus180]

Last night I was using my new E620 with the above lens. It was overcast conditions.
All was well and then the lens started "hunting" for a focus. It went on and on each time with every attempt at different shots with different zoom levels and camera settings. All of my other lenses worked OK.
Can anyone help?

[CallaWolf]

Re: Problem with 70-300 lens

Welcome to the 70-300 club

Unfortunately, low light is one of this lens' limitations - it doesn't like it, doesn't perform well in it...

I've got it on an E5 and it hunts like crazy when the day is grey (I really wish oly'd put a limiter on it).

Others will tell you of things you can try to improve things, but in the end you have to know the limitations of your equipment, accept them and find ways around them. Don't forget this is a BUDGET lens, excellent though it is.

[theMusicMan]

Re: Problem with 70-300 lens

Yep, as Ceri mentioned... welcome to the 70-300mm users club. This low light hunting is a common feature of this lens and is something you have to get used to.

Personally, and many here will already be aware of my personal opinion - I feel the 70-300 lens is an absolute corker of a lens for the price. I sold my Bigma 50-500 because I was getting better results with the 70-300 +EC14 than with the Bigma.

Get to know the lens, practice makes perfect as they say... and you will very soon be getting great results with it.

[crimbo]

Re: Problem with 70-300 lens

For low light I usually set the the focus to manual with the AEL/AFL set to focus...I focus manually then hold the AEL/AFL button to tighten up the focus...this is a difficult lens in low light/low contrast but even wide open it is worth it...
The ones in this album http://e-group.uk.net/gallery/showgallery.php?cat=1219 benefited from the high evening light levels on Shetland but are the best of around 50...so I got a 1 in 4 success rate

[Graham_of_Rainham]

Re: Problem with 70-300 lens

One of the advantages of longer lenses is the DoF is so much smaller that manual focus is easier. I use MF is preference to AF in all but very good light, as I can achieve a focus quicker than the AF

[Ian]

Re: Problem with 70-300 lens

The 70-300 has a very long focus range as it's a semi-macro as well as a telephoto. This means the focusing takes a lot longer from closest focus to infinity. At also means that if you are more than a modicum away from correct focus the range-finding of the phase detect AF sensor loses any ability to know which way to drive the focus, so it has a 50% chance of getting it wrong. If it gets it wrong then it's very difficult to recover without lots of hunting.

Low light makes things even worse as the contrast is much lower.

My advice is to use S-AF+MF mode and then use MF to get the focus almost right and then with luck when you half press the shutter release it will snap in to focus.

When in focus, this lens is very rewarding.

Ian

[Tordan58]

Re: Problem with 70-300 lens

My advice is to use S-AF+MF mode and then use MF to get the focus almost right and then with luck when you half press the shutter release it will snap in to focus.
Ian

Hi Ian,

What you write "and then use MF" could be misread. I suppose you mean the following:
Prerequisite: Have AF mode set to S-AF+MF
Focus manually on target (using the focus ring on the lens)
When you believe focus is right, half press the shutter release to activate AF and lock on target
If AF fails in locking and starts hunting then repeat (possibly aiming at another point)


/Tord

[abacus180]

Re: Problem with 70-300 lens

Thanks everyone. I thought the lens had developed a fault.
My main problem is that my eyes aren't nearly as good as they once were, therefore AF is a must. I'll try the MF route but is there anything else to try in AF before I have a go?

[Graham_of_Rainham]

Re: Problem with 70-300 lens

<snip> I'll try the MF route but is there anything else to try in AF before I have a go?

I have a laser pointer that can project a line on to a surface. I've used it to good effect on a few occasions. There is also the focus assist on the FL-50 that can be used. If you dont want the light from the flash, turn it to very low and point it away from the subject.

[Ian]

Re: Problem with 70-300 lens

Thanks everyone. I thought the lens had developed a fault.
My main problem is that my eyes aren't nearly as good as they once were, therefore AF is a must. I'll try the MF route but is there anything else to try in AF before I have a go?

I hope you got the gist of my suggestion

If you use S-AF+MF mode, you simply turn the focus ring until the picture is basically clear and not obviously out of focus, then press the shutter release half way and the AF kicks in and locks the focus. Basically you are using the focus ring to help the AF.

Try it and see!

Ian

[crimbo]

Re: Problem with 70-300 lens

Reason I use the cruder method of MF with SAF programmed the the AEL'AFL button is that I can take an picture ands if I do not have to refocus then the lens is set...also I have found in particularly low light situations that if focus is achieved with SAF MF then when you next press the shutter the focus sequence may start again... and an image is missed

[ringneck]

Re: Problem with 70-300 lens

Can I start a sub-section to the 70-300 club...called the 70-300 club:sub section 1 : "the 135-400 club".

You have all just described the antics of my Sigma 135-400 and I have to go manual 1st then lock on in AF....or if trying for a bird in flight just go with manual...and hope.

Keith