A900 and a Tamron1.4x converter examples

[sury]

A900 seems to be doing alright with "pedestrian" converters. Here is an example of an image taken with
A900 + Tamron 1.4x converter using a Vivitar Ser 1 70-210/f2.8-4 AF lens. The image following that is
a 100% crop. As always, all comments are appreciated. For the rest of the images, you can go here:
http://www.flickr.com/photos/bigsur/

with best regards,
Sury

image:

http://farm4.static.flickr.com/3118/314 ... 5a1a_b.jpg

100% crop

http://farm4.static.flickr.com/3087/314 ... 46a1_b.jpg

[David Kilpatrick]

Impressive but central - most teleconverters are OK for central resolution, it is at the edges they lose it.

David

[sury]

David,
If the teleconverters lose out on edges, then are they preferred to be used in a FF camera rather than on a APS-C body? Especially
something like A900 which has plenty of pixels to spare? Also, should I be using center weighted or spot metering?

with best regards,
Sury

[David Kilpatrick]

Most will be worse on full frame, better on APS-C. I don't think it matters what metering you use, but be sure never to overexpose. For many tele shots, with no sky and a darker subject like animal fur, minus 1 stop over-ride is always worth setting - a smaller aperture and faster shutter speed always help with TC/zoom combinations.

David

[sury]

David,
Thank you very much for your prompt response. Much appreciated. Talking about under exposure,
I am finding that my better shots with any adapter (whether TC, M42/MA, MD/MA) are when I underexpose
the image deliberately on both A900 and A100. I have not had time yet to open the A700 (still in the box)
to experiment with.
I am wondering why that is the case. I am finding this phenomenon consistently with about half a dozen MD lenses, a MF mirror lens and
about 4 M42 lenses. These lenses have fairly distributed focal lengths (45mm to 500mm). Only thing I can think of is the technology used
to caliberate lenses in yesteryears gave more conservative readings. A F4 lens might be (slightly) faster than F4 but they played it safe, for example.
Any comments?

With best regards,
Sury

[David Kilpatrick]

I can just tell you from experience that the lowering in contrast produced by adding a telecon is always best tackled by keeping exposure to the minimum. Along with the typical cropped compositions resulting. Individual TCs may also affect metering, especially on the old MD system, by failing to maintain a perfect link the MC coupling ring - and on the AF system, the aperture mechanism may also not be accurate.

David

[sury]

David,
Thank you. Your statement about keeping the exposure to minimum vindicates my position that the manual
lenses seem to do better when the light is bright (not a problem in Silicon Valley, CA) or with a flash. Anything
in between is pretty much a wash (no pun intended).

With best regards,
Sury