How do you test lens sharpness? Tamron 70-300mm VC.

I have a Tamron 70-300mm VC lens that I am not happy about. Over around 250mm it is not sharp at all. In fact, in my view the results are simply unaccptable. I sent it back to Tamron twice already - it is under six year warranty, and both times it came back as before. I am trying to figure out if I am asking for impossible for this lens, or am I doing something wrong?

And most important, I wonder if there is a standard way to test sharpness, is there a method that people use, something like using batteries when testing lens focus?

Both shots are at 300mm, 1/250 sec, F:8, ISO 320, unsharpened.

that doesn't look like a focus issue. Looking at those it looks to me to be simply crappy optics in the lens that are nowhere near as sharp as they should be. If your lens is this bad at f/8 nothing is going to help. I think given what you're asking you're asking the impossible of the lens. Hoenstly those look worse than just about any other lens I've seen and that includes EF-S 18-55 non IS kit lenses (which aren't spectacular)

icacphotography wrote in post #15946866
that doesn't look like a focus issue)

that would be my guess too.

but you might want to check out this thread.

https://photography-on-the.net/forum/showthre​ad.php?t=750736

i think there is an updated version of the template somwhere later in the thread.

Are those screenshots of image crops?

dalto wrote in post #15946903
Are those screenshots of image crops?

good catch, i didn't even notice the hand cursor in the one picture.

gotta know what we're looking at to make a judgement call.

maybe it's a photograph of a photograph on the screen


both at 300 mm :P

I opened the files in LR4, showed actual size (100%), and took a screenshot of those sections. If it is not the right way, I would appreciate the directions.

Lbsimon wrote in post #15947217
I opened the files in LR4, showed actual size (100%), and took a screenshot of those sections. If it is not the right way, I would appreciate the directions.

Open in LR, crop image, export image.

Edit: Also, did you have VC on when you took those shots?

dalto wrote in post #15947223
Open in LR, crop image, export image.

Edit: Also, did you have VC on when you took those shots?

Thanks, I will try again shortly, even though I did not see much of a difference.

Yes, the VC is always on when handheld.

I owned that lens and I thought it was a great lens. Do you have a filter on it? If so remove it and take a few pictures. Do you know any else with a camera that they can chech it also? I would think if Tamaron serviced it they would not send it to you with bad optics.

woodzy wrote in post #15947272
I owned that lens and I thought it was a great lens. Do you have a filter on it? If so remove it and take a few pictures. Do you know any else with a camera that they can chech it also? I would think if Tamaron serviced it they would not send it to you with bad optics.

No, there was no filter. All other lens that I have make very good sharp photos. Tamron 70-300 is the only one. I will try to do more experimentation, will try to compare it to the EF-S 18-200, and trying it on both the 60D and the T2i. But I would still like to hear your suggestions.

Your 60D would be capable of very good ISO and these are taken in broad daylight. Maybe bump the ISO a bit more for shutter speed? Yes I know it has near 4 stop VC but humour me and shoot at least 1/300 x 1.6 = 1/480s.

What was your shutter speed? It should be at least 1/500 to test.

My Tammy never looks like that. Turn the VC off, put it on a tripod, and shoot something static like a building. If it still looks like that, it's the lens. If it looks good, it's your hand technique.

Wow..

I am going to go thru a few shots of mine.. I want to see if I get similar results.. (I usually do not Pixel Peep.. )

what AF mode did you use?...it'd be more helpful if you could link the full photos to flickr, or some site where the Exif would be available...

I don't think the lens is supposed to be that soft...

if you want to really test it, set it on a tripod, and do testing that way...eliminate all the variables

If possible, maybe post a RAW file?