[btnapa]

I'm at it again. This time with tripod, 3 second shutter delay to eliminate shake. Both images taken at ISO 800 & F8. Distance ~ 55 yards. Click on any image to go to Flickr to see EXIF & also the original photos.

Tamron - cropped & auto levels in post


Pentax 55-300 cropped & auto levels in post



Seems like, again, the Tamron focus can't be perfectly nailed (even used live view and magnification of it)


Comments welcomed

Hi Michael, Something is not right with the 500. Can't put my hand on it. It looks either out of focus or there is a shake. Shutter of 1/125 may not be enough to keep it steady. Again, the bad copy I have (possible mold on the front element) looks sharper than your copy. As I mentioned in my earlier post, I also shot with a copy of the 500 which my friend owns and that one is a lot sharper than what I have. The only softness I have detected with this lens has been in medium to long distances. For close up, it is a as sharp as any lens I have tried on my Pentaxes. Again, this is with the copy that my friend owns.

Try a higher shutter speed and see what happens. Let's not forget that on your K-S2, this is a 750mm lens!

[Michael Piziak]

Hi Michael, Something is not right with the 500. Can't put my hand on it. It looks either out of focus or there is a shake. Shutter of 1/125 may not be enough to keep it steady. Again, the bad copy I have (possible mold on the front element) looks sharper than your copy. As I mentioned in my earlier post, I also shot with a copy of the 500 which my friend owns and that one is a lot sharper than what I have. The only softness I have detected with this lens has been in medium to long distances. For close up, it is a as sharp as any lens I have tried on my Pentaxes. Again, this is with the copy that my friend owns.

Try a higher shutter speed and see what happens. Let's not forget that on your K-S2, this is a 750mm lens!

Thanks for your comments/reply.

I'm simply can not able to nail the focus with the Tamron at long distance shots - even though I've used both live view magnification method and also have tried the green hexagon/focus indicator method. I do believe that focus is better at shorter distances - see my bird images from 15 yards in post #14 in this thread....

I will increase the shutter speed later and post again... Or perhaps if I take some photos of things at infinite distance (?) I would like to shoot the moon, but it's been snowy/overscaste for days here in W.V.

[btnapa]

I will increase the shutter speed later and post again.

I would be curious to see if the results improve. Thanks for posting your tests with this lens. I always wanted one of these lenses for their unique (donut shape rings) rendering and I am still looking for a clean/sharp copy.

[Michael Piziak]

I would be curious to see if the results improve. Thanks for posting your tests with this lens. I always wanted one of these lenses for their unique (donut shape rings) rendering and I am still looking for a clean/sharp copy.

Well, at shorter distances, this copy seems to perform pretty good. But the longer the distance, the less in focus things are - perhaps such a shallow DOF causes this more and more as distance increases (?)

From about 15 yards away (again):

[btnapa]

Well, at shorter distances, this copy seems to perform pretty good. But the longer the distance, the less in focus things are

Looks better but not exactly sharp. I am not sure what causes it. Perhaps that is the limit of the optics. I was expecting much better resolving power than this. I thought the out of focus donuts were the only weak point of this lens. I'll try my copy again just to see if it is any sharper than the results you are getting.

[Michael Piziak]

Looks better but not exactly sharp. I am not sure what causes it. Perhaps that is the limit of the optics. I was expecting much better resolving power than this. I thought the out of focus donuts were the only weak point of this lens. I'll try my copy again just to see if it is any sharper than the results you are getting.

Post some shots here if ya can

[Michael Piziak]

I decided to take several photos with the Tamron 500, starting with it focussing just before the bird house and then turning the focus ring as small an amount as possible and taking another, and repeating, until eventually the bird house would have to be in focus somewhere, and then continuing until it was focussing behind the bird house. Again, turning the focusing ring the absolute minimum that I could turn it with each photo. I increased the shutter speed to 1/250 and ISO 800 again. Tripod and 3 second delay used to eliminate shake. Here are the results of the 6 photos taken:

1


2


3


4


5


& 6


Well, #4 comes closest to being focused.

All I can conclude is that this lens or this bad copy of this lens simply is pretty much unusable. Some will credit much of this to it being a mirror lens. I dunno.
Regardless, it won't go out into the field with me. The Pentax 55-300 will be by my side, as it's clear that cropping from its 300mm produces a superior result.


Cheers

---

Last edited by Michael Piziak; 01-20-2022 at 02:33 PM.

[normhead]

#4 sharpened, lightened, a bit of saturation, a bit of contrast, a levels adjustment...
Really not too bad.

[wadge22]

All I can conclude is that this lens or this bad copy of this lens simply is pretty much unusable. Some will credit much of this to it being a mirror lens. I dunno.Regardless, it won't go out into the field with me.

A bummer if true.
I thought the bird photos you first posted looked pretty promising. But yes, those shots at further distances are pretty disappointing. I wonder if there's anything that can be done about it.

[btnapa]

Really not too bad.

Looks really good. Much improved.

---------- Post added 01-20-22 at 04:13 PM ----------

Some will credit much of this to it being a mirror lens.

True, but somehow I think the Tamron 500 mirror is a much better lens than what we are seeing here.

[UncleVanya]

I'm at it again. This time with tripod, 3 second shutter delay to eliminate shake. Both images taken at ISO 800 & F8. Distance ~ 55 yards. Click on any image to go to Flickr to see EXIF & also the original photos.

Tamron - cropped & auto levels in post


Pentax 55-300 cropped & auto levels in post



Seems like, again, the Tamron focus can't be perfectly nailed (even used live view and magnification of it)


Comments welcomed

Clearly the Pentax wins this round. But honestly the differences aren’t “night and day“.

[normhead]

Clearly the Pentax wins this round. But honestly the differences aren’t “night and day“.

I think maybe your definition of "night and day" and mine are a little different. Given that the Pentax has a considerably larger enlargement factor, the results are pretty convincing. What would be the advantage of using the Tamron, if you had the Pentax?

[UncleVanya]

I think maybe your definition of "night and day" and mine are a little different. Given that the Pentax has a considerably larger enlargement factor, the results are pretty convincing. What would be the advantage of using the Tamron, if you had the Pentax?

Norm - strictly speaking I’m not at all concerned with what was done. I’m only looking at the final results and saying that yes the Pentax is better but you could get away with the Tamron if you weren’t looking as closely as we are in this comparison.

Clear winner, not however a case of toss that lens in the bin and run screaming from the area.

[normhead]

Norm - strictly speaking I’m not at all concerned with what was done. I’m only looking at the final results and saying that yes the Pentax is better but you could get away with the Tamron if you weren’t looking as closely as we are in this comparison.

Clear winner, not however a case of toss that lens in the bin and run screaming from the area.

I actually think using Topaz or something like it you could make a go of it, if you get the focus thing straightened out.