Not totally unhappy with the new (to me) tamron, but...

[pjaye]

Not totally thrilled either. These were taken outside, with the Tamron 18-270 3.5-6.3. Two pictures came out totally dark, no idea why.

These were the ones I was sort of happy with.

 

[tirediron]

Why? For a super-zoom those seem pretty decent; reasonably sharp, no scarey amount of distortion, and I don't see any horrible CA.

 

[pjaye]

Why? For a super-zoom those seem pretty decent; reasonably sharp, no scarey amount of distortion, and I don't see any horrible CA.

I think because some of the pictures are still coming out darker than I think they should be considering the settings and the light. But I also think a lot of the problem is user error and I just need to get out there more and keep practicing.

 

[Derrel]

1409 has a sort of watercolor effect, meaning smeary detail at the pixel level when zoomed in and examined; it looks like maybe a good deal of noise reduction was applied, possibly due to a fairly high ISO setting. Same with the first squirrel shot. The bird photo shows a lot of chroma noise in the smooth areas of the image, but the bird appears well-focused and sharp-ish. Honestly, it looks to me that the weaker link is sensor performance on these. I cannot get any EXIF info, and just looked at these magnified to 2x on-screen.

If any image was grossly under-exposed, and then processed, it's not a good, fair way to evaluate the image quality the lens can produce. Shot 1409 for example, that is the classic "watercolor effect" of noise reduction...the per-pixel info sort of breaks apart when you zoom in...it's not necessarily the LENS that is doing the damage.

As far as pictures coming out darker than expected: I would look closely at the camera settings (accidental Minus Exposure comp for example), and also consider that with a long telephoto, many times the metering will be measuring a VERY small area of the real world, as opposed to using a wider-angle lens that has a much broader area of acceptance. With darker subjects in the metering area, you might tend to get dimmer exposures. ALSO, with the HUGE number of lens elements in a super-zoom, many times the actual T-stop or actual transmission of light, is MUCH lower than the computed f/stop value. EACH air-to-glass surface loses light, even when multi-coated, and superzooms with 19,20,21,23 elements can have lowish T-stops compared to say, a 7-element prime lens.

 

[pjaye]

Thank you Derrel. They were not under exposded and just slightly cropped in processing. My Iso was very high so that might be the issue. I now remember playing with the exposure button a few days ago. I'm out of the house right now but when I get home will post the setting. I really appreciate you and tirediron chiming in.

 

[pjaye]

Settings -

Focal Length 270
ISO 1250 <~~~ had no idea it was that high
Metered - center weight
Shutter Priority mode
F 7.1

Exposure 1/800

 

[DarkShadow]

I have this lens and is does produce sharp images. As most lenses of this type seem to always be sharper stopped down in the f8 area but don't be afraid to open it up to let more light in. Ideally you want low ISO but in the real world it does not always happen.One thing I have been learning a lot is to work with High ISO shots. If you under expose in camera with a high ISO the noise is going to kill it. I over expose most of my shots and some to the point of almost blown out or clipping. My favorite spot I go shooting birds the sun is always in front of me peaking through tree branches and usually the birds are in the shade and If I did not over expose I would end up with all silhouette shots, So I over expose to compensate for shade and strong backlighting. I also don't use in camera Noise reduction or lighting optimizer all turned off. I also don't use noise reduction at all in post.

 

[DarkShadow]

Just an example if you don't mind, here is one with the sigma 150-500mm at 439mm - 1/800 - f/8 - ISO 2500 +2/3 Exposure Value. I have one's with the Tamron as well with High ISO.
IMG_2178 by DarkShadow191145, on Flickr

 

[Derrel]

ISO 1,250...yeah...I kind of suspected it was elevated.

 

[pjaye]

I have this lens and is does produce sharp images. As most lenses of this type seem to always be sharper stopped down in the f8 area but don't be afraid to open it up to let more light in. Ideally you want low ISO but in the real world it does not always happen.One thing I have been learning a lot is to work with High ISO shots. If you under expose in camera with a high ISO the noise is going to kill it. I over expose most of my shots and some to the point of almost blown out or clipping. My favorite spot I go shooting birds the sun is always in front of me peaking through tree branches and usually the birds are in the shade and If I did not over expose I would end up with all silhouette shots, So I over expose to compensate for shade and strong backlighting. I also don't use in camera Noise reduction or lighting optimizer all turned off. I also don't use noise reduction at all in post.

Thank you! I don't know if I have in camera noise reduction on, I'll check. I will also try your tips. I'm way to critical of my own work, or so I've been told Since this was a pricey purchase of a used lens, I was worried there was something wrong with it, but like I said before, I think most of it is user error. This was the first time I got to really try it out. I used it yesterday but it was a super cloudy, dull day and all those pictures came out really dark. Today was better. I'll keep practicing and use your tips.

 

[pjaye]

Thanks guys. I sincerely appreciate your help. Made me feel better about the lens. I'll keep practicing, change some settings and see what happens. Thanks for taking the time to help. (I love this board)

 

[DarkShadow]

Don't worry barb your doing just fine and practice is the only way we all get better just like anything else. If your shooting jpeg then noise reduction is just a matter of choice on or off. Sometimes it may do a good job and other times it seems to soften a image to much. I personally rather have control of it in post but like I said I never use it. If your shooting raw files then it don't matter if it's on or off.

 

[pjaye]

I shoot both. Not sure why, since I absolutely hate, and suck, at editing. I generally just use picassa to do a crop and warm up the picture a bit if necessary. I think I'll take the noise reduction off since I mostly just use the jpeg's.

 

[DarkShadow]

Editing is a skill in it's self. I am not that great at it my self but getting better at as I go. When I get it right in camera or at least think I did then editing becomes so minimum and quick. One thing great about raw is you capture the most detail from the sensor and when a picture is the most important but something goes wrong you have a better chance of saving it and you can always go back to the original raw and re do at a latter date.

 

[jamesparker1250]

Some nice pictures