Blur with zoom, tripod doesn't help

aleksamoon · Aug 20, 2016

I've recently been experimenting with taking portraits (and other shots) with a Promaster Aspherical 28-200mm f3.8-5.6 lens on a Sony Alpha 55. When zoomed out all the way or nearly all the way the image appears to be quite blurry all over with no defined focal point. (I'm using single-point autofocus for these shots, which works fine at shorter focal lengths, as well as a tripod). This has happened in both full sun and golden hour conditions. It also happens when shooting in both RAW or JPG. These images are sometimes soft, yet usable (if I'm being liberal) as uploaded off my memory card, the problem really gets out of hand when I try need to zoom in to crop the photo at all - the detail just isn't there and the blur is overwhelming. ISO for all shots is 100.

I did some experimenting with a book in the grass last night to try to determine if I might have a front or back focus problem. When I shot the book at a distance of about 30 feet the image was just soft all over. One taken with the same exposure settings about 10 feet closer came out more clear (although still not a high enough quality to crop) and showed the grass more or less in focus on the same plane as the book.

Also took a few shots of a tree also about 30 feet away. It came out very blurry at slower shutter speeds (1/2 second and 1 second). What would be causing so much blur on a still object while using a tripod? Steadyshot was on for all of the photos I'm speaking about and there was no wind. I'm not using a remote, so could it still be camera shake from me touching the shutter button?

Sorry that I'm not able to upload more pictures, having tech difficulties with website at the moment. Any ideas would be MUCH appreciated!! I'm wondering if there might be some kind of film on the lens that I'm not seeing with naked eye (cleaning with lens wipes), if this might be some kind of damage to the camera itself, to the lens, or if this is just a crappy lens? Was also going to upload a closeup of a flower taken at 180mm in daylight that, while not blurry, also shows a lack of detail (no tripod on that shot). Thank you in advance!

aleksamoon · Aug 20, 2016

Here is the photo of the book a little closer (about 20 feet away. I can see that the book at the grass near it are more in focus that the rest of the picture, but still not good enough quality to crop and do any zoom in post. Looks to be ever so slightly behind the book to me. How does it look to every one else and could this be causing all of he problems I'm describing? Thanks!

The_Traveler · Aug 20, 2016

shutter speeds and focal lengths?

480sparky · Aug 20, 2016

Camera Maker: SONY
Camera Model: SLT-A55V
Lens: ----
Image Date: 2016-08-19 20:09:18 (no TZ)
Focal Length: 200.0mm (35mm equivalent: 300mm)
Aperture: ƒ/5.6
Exposure Time: 0.333 s (1/3)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Auto Bracketing
White Balance: Manual
Light Source: Shade
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
GPS Coordinate: undefined, undefined
Caption: SONY DSC
Software: SLT-A55V v1.10

Camera Maker: SONY
Camera Model: SLT-A55V
Lens: ----
Image Date: 2016-08-19 20:05:14 (no TZ)
Focal Length: 200.0mm (35mm equivalent: 300mm)
Aperture: ƒ/5.6
Exposure Time: 0.500 s (1/2)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Auto Bracketing
White Balance: Manual
Light Source: Shade
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
GPS Coordinate: undefined, undefined
Caption: SONY DSC
Software: SLT-A55V v1.10

Camera Maker: SONY
Camera Model: SLT-A55V
Lens: ----
Image Date: 2016-08-19 20:10:54 (no TZ)
Focal Length: 200.0mm (35mm equivalent: 300mm)
Aperture: ƒ/5.6
Exposure Time: 0.125 s (1/8)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Auto Bracketing
White Balance: Manual
Light Source: Shade
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
GPS Coordinate: undefined, undefined
Caption: SONY DSC
Software: SLT-A55V v1.10

If you're using a tripod, you're still doing something wrong. A common mistake would be jamming the shutter button. Try using the camera's self-timer, or a remote release.

Another problem is using an über-cheap tripod. The $15 ones they sell at the grocery store are gonna be junk.

dxqcanada · Aug 20, 2016

Turn SteadyShot off when using a tripod.
Do the images turn out more in focus if you manually set it (use the Focus Magnifier to get better view) ?

smoke665 · Aug 20, 2016

Just curious did you buy this lens used? I bought a cheap Sigma Aspherical lens off Ebay that would not focus sharp AF or manual. Had to send it back.

SCraig · Aug 20, 2016

I think part of the problem is that you might be starting to see the difference between a $80 lens and a $500 lens.

480sparky · Aug 20, 2016

The images are in focus. The issue is motion blur caused by the camera moving.

Sometimes, this is caused by the image stabilization system is not needed, yet being left on when the camera is on a tripod.

aleksamoon · Aug 20, 2016

dxqcanada said:
Turn SteadyShot off when using a tripod.
Do the images turn out more in focus if you manually set it (use the Focus Magnifier to get better view) ?

I do remember reading that the Steadyshot is not compatable with a tripod. Thank you for reminding me. I don't think this is the problem though, as I only turned it on after noticing this problem at a shoot the previous day when Steadyshot was not one. I'll play around with manual focus using the magnifier. I have been avoiding manual focus because I don't have the best eyesight, but seems like the only way to rule out a problem caused by auto focus.

aleksamoon · Aug 20, 2016

480sparky said:
The images are in focus. The issue is motion blur caused by the camera moving.

Sometimes, this is caused by the image stabilization system is not needed, yet being left on when the camera is on a tripod.

Thank you, you are right. However I don't think this is the solution as I only turned Steadyshot on after noticing the blur at a shoot the previous day when it was not on. I'll be sure to turn it off with tripod use in the future though

aleksamoon · Aug 20, 2016

SCraig said:
I think part of the problem is that you might be starting to see the difference between a $80 lens and a $500 lens.

Haha, I'm not seeing the "difference" because I've never had the privilege of using a more expensive lens

aleksamoon · Aug 20, 2016

smoke665 said:
Just curious did you buy this lens used? I bought a cheap Sigma Aspherical lens off Ebay that would not focus sharp AF or manual. Had to send it back.

Nope, it was purchased new a couple years ago. Barely ever used it until now.

aleksamoon · Aug 20, 2016

480sparky said:
Camera Maker: SONY
Camera Model: SLT-A55V
Lens: ----
Image Date: 2016-08-19 20:09:18 (no TZ)
Focal Length: 200.0mm (35mm equivalent: 300mm)
Aperture: ƒ/5.6
Exposure Time: 0.333 s (1/3)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Auto Bracketing
White Balance: Manual
Light Source: Shade
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
GPS Coordinate: undefined, undefined
Caption: SONY DSC
Software: SLT-A55V v1.10

Camera Maker: SONY
Camera Model: SLT-A55V
Lens: ----
Image Date: 2016-08-19 20:05:14 (no TZ)
Focal Length: 200.0mm (35mm equivalent: 300mm)
Aperture: ƒ/5.6
Exposure Time: 0.500 s (1/2)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Auto Bracketing
White Balance: Manual
Light Source: Shade
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
GPS Coordinate: undefined, undefined
Caption: SONY DSC
Software: SLT-A55V v1.10

Camera Maker: SONY
Camera Model: SLT-A55V
Lens: ----
Image Date: 2016-08-19 20:10:54 (no TZ)
Focal Length: 200.0mm (35mm equivalent: 300mm)
Aperture: ƒ/5.6
Exposure Time: 0.125 s (1/8)
ISO equiv: 100
Exposure Bias: none
Metering Mode: Matrix
Exposure: Manual
Exposure Mode: Auto Bracketing
White Balance: Manual
Light Source: Shade
Flash Fired: No (enforced)
Orientation: Normal
Color Space: sRGB
GPS Coordinate: undefined, undefined
Caption: SONY DSC
Software: SLT-A55V v1.10

If you're using a tripod, you're still doing something wrong. A common mistake would be jamming the shutter button. Try using the camera's self-timer, or a remote release.

Another problem is using an über-cheap tripod. The $15 ones they sell at the grocery store are gonna be junk.

Thanks for posting the info for everyone. Yes, I'm using a tripod. What do you mean by jamming the shutter button? I'm pressing it as gently as I can to try to reduce any shake. I will take more photos with the timer today and report back.

Dave442 · Aug 20, 2016

For 300mm equivalent then you should really use the self timer to release the shutter with the shutter speeds you are using. Even better if your camera can raise the mirror prior to taking the shot. The first two images have motion blur.

Really better with a faster shutter speed for this kind of test. In the first shot if you went to ISO 400 then to f/8 you would have 1/13 sec shutter speed in place of 1/3. For this lens you want to stop down to around f/8 at the long end to increase sharpness.

Don't plan to crop images when using this lens.

smoke665 · Aug 20, 2016

aleksamoon said:
Nope, it was purchased new a couple years ago. Barely ever used it until now.

Then as previously suggested, you're probably getting motion blur. I downloaded your treee shot, blew it up and clipped this section out of the corner of the box. This gives you a pretty good view of the double image.

When you're shooting with a longer focal length, even slight movement can be magnified, especially at such slow shutter speeds. I'd suggest you adjust your ISO and/or F stop to get your shutter speed up to equal the focal length of the lens and try it.