Photoclubalpha

Since I have my A900, I have not take to much picture with the 20mm, probably because the summer was not there and I have missed the autumn too last year. But, after seeing some question about this lens on the A900, I have took some picture yesterday to play with it, and I have found that the lens is better than I expected.

Here is the result : http://www.pbase.com/nadeauf/minolta20mmrs



To save space, I'm compressing the picture with Pbase ... but the result is not really good ... , but you are able to see where the picture is sharp or not from center to corner.

Regards,

Frank

The lens looks like a first-quality example. But the sky at ISO 200 in the tree shot is extremely noisy - WB may be the culprit.

David

Lens looks good, you have some serious dust issues on your sensor though!

I have a 20mm non-RS version. can anyone say how this compares to the RS (&Sony?). For high quality landscape work on the A900, is it worth replacing with a later version?

Wes Gibbon wrote:I have a 20mm non-RS version. can anyone say how this compares to the RS (&Sony?). For high quality landscape work on the A900, is it worth replacing with a later version?

I have experimented the First version on my Maxxum 7D in the past and found that there was not difference between the 17-35D and this is the reason why I sold it.

But I know that the RS version support a Circular Aperture but the number of internal element is still the same. Better coating ? who knows ...

I think the first version should be a good performer too.

Regards,

Frank

David Kilpatrick wrote:The lens looks like a first-quality example. But the sky at ISO 200 in the tree shot is extremely noisy - WB may be the culprit.

David

I will post a better picture tonight, with no Pbase compress. of one or two selected picture. Do you have a preferred picture ?

Regards,

Frank

Thanks to Remote Desktop. I have spend a moment in lunch time to connect to my home computer and I have upload and not compress with pbase two of the F8 and F13 picture of the 20mm F2.8. And I have tried to reduce the Sharpness setting in Lightroom (but not easily because of the slow refresh rate of the picture in remote mode).

Here is the result :


http://www.pbase.com/nadeauf/image/1105 ... iginal.jpg (10 Meg file)


http://www.pbase.com/nadeauf/image/1105 ... iginal.jpg (20 Meg file)

Regards,

Frank

Frank, I'm afraid you desperately need a sensor cleaning.

Dr. Harout wrote:Frank, I'm afraid you desperately need a sensor cleaning.

Yes I know, but in this case, there was more dust on the back of the lens that straight on the sensor. But I know I need to clean it. I'm searching for the best way of doing this at home.

Next time I'm doing test like that, I will come to you cleaner .

I'm shooting Prime only, and this make me more in a danger way of having dust on my sensor. But, for the good detail and result of Prime lens, this is a very small problem for me.

Probably, David already know the answer about the best none expensive way of cleaning the Huge A900 sensor.

regards,

Frank

InTheSky wrote:

Dr. Harout wrote:Frank, I'm afraid you desperately need a sensor cleaning.

Yes I know, but in this case there was more dust on the back of the lens than straight on the sensor.

Definitely not. Dust on the lens elements may reduce contrast and increase flare (if it's a lot of dust) but will never become visible as individual dust spots in the image.

InTheSky wrote:Probably, David already knows the answer about the best inexpensive way of cleaning the huge A900 sensor.

Simply blow some puffs of air onto it, using a bellows blower (never blow onto your sensor with the mouth!).



This is the Hama "Dust Ex" (image from the [url=http://www.hama%20de]Hama website[/url]) which I have. Similar devices exist from many other manufacturers, for just a few bucks.

-- Olaf

I don't know how it is in different countries, but in mine for example, I would suggest to buy such blowers from pharmacies, thus spending much less from one purchased from a photographic store.

I have the opportunity to get this lens fairly inexpensively but could not realize its full potential on my a700. I already have a 24/2.8, and to grab up a 20/2.8 might just be vanity...but I wish I'd found the 20mm first.

Did you notice some focus shift with that lens?

youpii wrote:Did you notice some focus shift with that lens?

Good point! The Minolta AF 20 mm 1:2.8 suffers from a fairly strong aperture-related focus shift indeed, much like the AF 50 mm 1:1.4. When focusing at f/2.8 but shooting at f/5.6 then the plane of focus will be closer to the camera than intended.

-- Olaf

For now I have not seen this effect. The kind of picture I have take for now with the A900 was more landscape with far subject.

But I have just check on my day of shooting with some composition with my Girlfriend on the front of the picture and every picture are in focus.

Has David told before, It is look like that I have a very good copy of this lens.

I will even check on my next shot for the focus precision and come back to you, but for now, this lens impress me a lot on the A900.

The only wish I could have for this lens is to be small like the 24mm or the 28mm ... , but I think it to much demanding for a wide angle like that .

Regards,

Frank