[sonypentax]

I am finding the vivitar to be a better lens throughout it's whole zoom range with the Tamron being slightly sharper at 70mm compared to the 75mm but oly by viewing at 100%

Your thoughts? Thank you!


top picture vivitar

second tamron

both macro shots at the equivalent 200mm range

bokeh slightly less busy with the tamron imo

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[marcusBMG]

This 75-205mm has good reviews here and I think Kiron at that time made good tp zooms. I've had 80-200mm f4, 80-200mm f4.5 and currently have the VS1. All are good sharp lenses esp stopped down.
Difficult to draw any conclusions viv a vis the tamron from a couple of hand held (I guess from the different perspective) shots. A considered comparison would take a lot of of well controlled (tripod mounted, remote shutter, magnified/live view focus) comparison shots at varying focal lengths and focus distances to build up a perspective of the relative merits of the two particular examples of the lenses. But slight differences can easily be merely sample variation.
My kiron VS1 is slightly sharper at 210mm than the tamron, but worse at 70mm, and the tamron has better contrast at all times. It's common actually for the better tp's of that era to have pretty similar IQ once stopped down.

[stevebrot]

Welcome to the Pentax Forums!

A few questions/comments:

It is not clear what version of the Vivitar you are using (there were three in multiple mounts) or how the comparison shots were made (taking aperture, tripod?, focus method, number of focus attempts, etc) and whether both were made using the same adapter. It is also not clear whether these images are reduced from the full frame on the A7, are arbitrary crops from the full frame, or are full-resolution crops.

I own the 19AH and have found that critical focus is difficult as is using the lens on tripod without a collar. The bottom image appears to be missed focus. That being said, I would say that the Viv appears to be a decent lens for the subject in your examples.

Do you have photos taken at moderate focal lengths and more common distances?


Steve

[stevebrot]

It's common actually for the better tp's of that era to have pretty similar IQ once stopped down.

Competition was very fierce at the time and the photomagazines would print the comparison reviews side-by-side along with bench-measured resolution numbers. As a result, performance was pretty consistent within a market segment.

I hate to say it, but in addition to the Tamron 19AH, I also own the rather nasty, but very compact, Tamron 70-200/4-5.6 158A. I have done table-top testing of these two against each other as well as some limited outdoor stuff and am embarrassed to report that the 158A does much better than expected and essentially equals the 19AH for some subjects.


Steve

(...the 158A is so plasticy I sort of hate to touch it...)

[Kerrowdown]

Welcome to the forum, sorry I can't comment as I have no experience of either of these lenses.

[goatsNdonkey]

I have an old screw mount Vivitar f3.8 75-205 close focusing zoom. For decades, it was my main lens for my Ricoh Singlex TLS body, along with my Takumar normal lens. I always loved that it was a 2-touch zoom -- no dreaded zoom creep, if pointing it downward on a tripod or copy stand. I didn't have another zoom to compare it to in those days, and my only Tamron I have owned is an SP series f3.5-4.2 28-80 with a k-mount adapter. I could try to compare them at the 75-80mm comparable lengths, but alas the old Vivitar has developed quite a garden of fungus inside of it. I love that old lens...maybe I'll learn how to clean its innards sometime.

[Unregistered User 8]

Hi sonypentax. Welcome to the forum.

[sonypentax]

Will post pictures later. The vivitar is the 75-205mm 3.8 essentially a scaled-down refined copy of the first vivitar series 1 Kiron version. No fogginess occurs with this lens. It does have some purple fringing yet not as bad as the 19ah.

From 150mm-200mm the 19ah shows increased fogginess in the image and the examples that I posted show the difference in macro, full frame no cropping. The vivitar shows no such fogginess and lack of clarity.

19ah strength is its sharpness from 70-150mm. From then on it falls apart. Nice bokeh as a trade-off slightly less busy than the 75-205

As a sidenote I took some shots with the Kiron first edition series 1 70-210 3.5 and found it to have NO purple fringing and just as sharp as the 75-205 3.8.

My next posting this weekend will consist of a comparison between the 19ah and three vivs (first and second edition series 1 and the 75-205 3.8)

Then another comparision between the 19ah with the 103a and the 52a just for kicks

All focal lengths

[goatsNdonkey]

sonypentax, how about some pictures of the lenses,too? Sometimes there is more than one version of a certain aperture-focal length lens from the same brand.

[stevebrot]

It does have some purple fringing yet not as bad as the 19ah.

From 150mm-200mm the 19ah shows increased fogginess in the image and the examples that I posted show the difference in macro, full frame no cropping.

OK, so they were down-sampled to the current 1350x900 resolution.

My copy of the 19AH has neither of these problems, but I shoot it on APS-C and film. I still believe that there is missed focus on the 19AH image, based on the sharp regions of that image. Not a big deal, they are old lenses and decent performance from any zoom of that vintage today is something to celebrate. I am looking forward to seeing a full suite of comparison shots from these lenses. Again, welcome to the Pentax forums!


Steve