[jabe]

Hi, I am brand new to this forum and also brand new to DSLR. I have a Pentax kx. I have taken some wonderful pictures. I have the DAL 55 -300 lens.
The problem I have been having right from the beginning however is, I have trouble with the focus on this lens when I try to get a close up. It just whirs and whirs and doesn't focus at all. (I have been doing some reading and understand this to be "hunting"o If I try to press the shutter button it won't work. I am fine when it is at a distance from the object but when I try to get close. Forget it.
I am new to all this so please be gentle with me. What am I doing wrong?????
Thanks

[dmeadows85]

How close are you to the object you're trying to focus on? All lenses have a " minimum focus distance," which means an object needs to be inches or, in some cases, feet away in order for the lens to focus. So, if a certain lens has an 8 inch minimum focus, anything less than 8 inches from the lens physically cannot be in focus.

Hope that makes sense!

[patrick9]

You don't say how close you are trying. You may be getting to close for the lens to focus. There is a minimum distance that a lens can focus at. Try backing up a bit and see if that helps.
Welcome to the Forums


I type to slow

[Numtini]

Looking at the review database, that lens has a minimum focus of 55 inches.

[jabe]

Wow! Thanks for this information. I didn't realize that I couldn't get close to flowers etc. What lens would be a good choice if I want to take closeups of flowers?

[interested_observer]

Also, how light is the environment? and are you trying to take images in the shadows? Images in the late afternoon, early evening when there is not a lot of light?

You can always, switch to manual focusing and then manual focus and take the image.

[snostorm]

Hi jabe,

dmeadows probably is on the right track. The DAL 55-300 has a MFD of 55.2" (140cm), which is actually pretty close for a 300mm lens -- older designed 300mm lenses have MFDs from 6-10 ft (2-3.3 m).

Compacts and super zoom bridge cameras can focus much closer at 450mm EQ (the same FL EQ as an APS-C DSLR with a 300mm lens) because the actual FL of the lens is much shorter. For a 1/2.3" sensored camera, a 450mm EQ actual FL would be around 83mm, so should be able to focus much closer. You'll have to get used to this limitation if you're coming from a bridge camera to a DSLR.

There are closer focusing long lenses though -- for example, the DA 18-250 will focus down to about 1.5 feet, so can be very useful if you want to shoot long FL, but at closer distances.

Scott

[Na Horuk]

Switch to manual focus (AF/MF button on camera body) and twist the focus ring all the way to the side. One side is infinity, the other side is near focus. When you have it at nearest focus, simply stand in front of an object and get closer until it gets in focus. Or move farther away.
At the closest focus, you also have the highest magnification that the lens is capable of.
Macro lenses have the ability to focus so near that you get 1:1 magnification.
Beware some third party cheap zoom lenses that claim to be "macro" - they probably arent. Check their actual magnification ratio to know for sure.

[Oldbayrunner]

What I have found with slow longer telephoto lenses and you are within it's focal length is to use spot focus to cut back on lens hunting, especially if there is a lot of closely related elements in the shot. If you are capturing birds in flight then use shutter priority, leave your focus on 5 or 11 points and switch your metering to spot, your background might blow out but the metering on your subject will be spot on with less lens hunt.

[Just1MoreDave]

Wow! Thanks for this information. I didn't realize that I couldn't get close to flowers etc. What lens would be a good choice if I want to take closeups of flowers?

Do you also have the DA 18-55? That should do a good closeup. Its minimum focus distance is 10 inches.

[sterretje]

The DA18-55 gives .33x magnification; the DA55-300 gives .28 magnification. So the DA18-55 is the better option for this.

And next you will probably start looking at close-up adapters (e.g. Raynox) or real macro lenses.

[Yos]

I think you have your answer why your lens is "hunting" but if you enjoy close up shoots why don't you save up for a macro lens
Or maybe try out some close up filters for your DAL 55-300
Happy shooting

Edit: I type to slow

[Na Horuk]

Btw, macro lenses have a great close focus ability, but they usually have rather slow AF. They have a much longer focus throw than regular DA lenses, so there is a bigger chance the AF will hunt. Some macro lenses have a focus limiter to help deal with that. Close up photography simply takes time - you usually need a tripod and (ring)flash if you want to do it really right. But macro lenses have great IQ and can focus as near as a couple inches in front of the lens.
Oh, and one more thing. The nearer you focus, the shallower the depth of field is. So you need to use a higher aperture number, or take multiple shots and stitch them in software.

[jabe]

Thank you all for your help. I have learned a few things from all of you already. As soon as the weather clears up I will try to get some pics.
Thanks again.

[JimJohnson]

Wow! Thanks for this information. I didn't realize that I couldn't get close to flowers etc. What lens would be a good choice if I want to take closeups of flowers?

Depending on your needs, a possible option is to take your photo as sharply as possible*, and then crop to obtain the desired image size. The limit is how much you have to crop versus the desired size of your print. However, if it works, it is MUCH cheaper than purchasing a macro lens!

* a tripod may be necessary