Problems with Sony 75-300 lens

[Gen244]

Hi everyone,

Recently I tried to take a picture of the moon using my Sony 75-300 lens and was very disapointed. (Note I am talking about the non-G model!)

My camera wouldn't auto-focus but this was to be expected, at least in my experience with night photography. So I used manual focus and much to my surprise I found that the change in image size was extreme.

The moon went from more than filling the entire image to only filling 1/4 of the image!

So I'd like some advice as to whether I am doing something wrong or whether I'm simply have the wrong tool for the job. At this point this lens seems to zoom no better than my Sony 18-250mm lens and I'm close to trying to sell it.

[hoffy]

Hi everyone,

Recently I tried to take a picture of the moon using my Sony 75-300 lens and was very disapointed. (Note I am talking about the non-G model!)

My camera wouldn't auto-focus but this was to be expected, at least in my experience with night photography. So I used manual focus and much to my surprise I found that the change in image size was extreme.

The moon went from more than filling the entire image to only filling 1/4 of the image!

So I'd like some advice as to whether I am doing something wrong or whether I'm simply have the wrong tool for the job. At this point this lens seems to zoom no better than my Sony 18-250mm lens and I'm close to trying to sell it.

Are you using the wrong tool? I suppose you could say that is relative. If you don't have anything else, then I suppose you are using the right tool!

Considering the lens (bottom of the rung consumer zoom) and the focal length, I would say that this kind of behavior sounds about right. There will always be some magnification difference when focussing and the longer the focal length, the more pronounced it will be.

That being said, you should be able to crop a reasonable image of the moon. I did some hand held shots with a very similar lens (the minolta granddaddy of that one) a few years ago and they came up a treat with a bit of a crop.

Cheers

[andrewda]

Hi, this is expected from this lens as it is fairly cheap kit lens. I have this lens from when I purchased my A100 back in 2007 and might have used it once or twice since then. Luckily I have the Minolta 300 APO f4 lens. You will struggle to sell the 75-300 lens as it is not really worth anything second hand.

Andrew

[nivekeel]

This lens's Maximum magnification is 1:4 (0.25x)
according to your figure of 1/4 the frame, that sounds pretty much right.
But to adjust your quote, trying to auto focus on a moon is not that hard since it is the brightest thing you can see on the sky at night (clear sky). Or simply adjust to a manual focus to infinity does the same job.
Furthermore, your 18-250mm lens has a max magnification of 0.29x which is a little better than the 75-300mm. However, be aware that 0.25x is the most usual magnification for a long zoom lens anyway. Not many of those have higher than 0.25x.