Second chance to the Minolta 500mm Reflex on A900

[InTheSky]

After having sold first the lens with my 7D ... and having sold a Sony version with some attempts with the A700 and the A900 ... Some discussion on Dpreview has forced me to tried an another time the lens on my A900.

Well ... I received the lens a few days ago ... and just found time yesterday to go outside on "day light". Day light a a quick work to say that there was not a good light and a some smog in the air ...

http://www.pbase.com/nadeauf/secondchan ... reflexa900



Again ... It seams that there is something in the lens that limit to feed full detail on the Sensor ... But ... I cannot explain what ... It is not looking as it is a real optical problem ... Like a smog or effect that the digital sensor don't like. Probably David will have good explanation about that. (and I don't think is because of not enough fast exposition time, the SSS looks very impressive with the lens ... even the Focus ability for F8.0)

If I pumping up the contrast the image start to look good ... but not enough.

This is the best for now with What I got on the street : (I reduced the image max 4000x4000) because In my taste there is not place for more pixels with this lens ...

Probably I'm stubborn ... but I have idea that this lens should be able to give good result ... , waiting for good light.

If I have time this weekend and it is not too cold, I will try this challenge : 500mm Reflex vs 50-500mm , and 200mm HS + 2X TC. I'm pretty sure who will win in detail ... but let's give it a chance again .

Regards,

Frank

[InTheSky]

Is there a reason why there is vignetting with a Mirror design lens ?

Regards,

Frank

[Javelin]

Is it possible SSS doesn't work as well with that lens? I ask because it looks a little soft like you get with a slow shutter. the one I tried seemed sharper than that and was thinking about buying one eventually

[David Kilpatrick]

The vignetting is inherent to the design. The lens is temperature sensitive, like all mirror lenses, and may give it sharpest results when the entire lens is at 20C (the normal 'standard' for temperature related design aspects). It also has a very inefficient lens hood and shows loss of contrast due to flare, but I've never seen a 'proper' lens hood made to fit it.

David

[Argonaut]

I've owned this lens for a long time and agree with your observations. I carry it when I must travel light, but if I am really serious about wildlife shots I take my other "bargain" tele, a [discontinued] Sigma 400mm APO macro (don't get one unless "macro" is part of its name - the non-macro is a very ordinary lens). It's heavier and larger, but it's better in several ways. It seems to be easier to hand-hold because of its length and heft compared to the mirror lens, but of course a tripod is always a good idea.

The vignetting can be dealt with in post; Lightroom has an easy to use anti-vignetter. The doughnut holes in the bokeh are nearly impossible to remove - I like to tell people "I meant that." I'd be curious how anyone has processed images to give them some more snap. I mess around with it, but am always looking for better techniques.

[David Kilpatrick]

I just use the doughnut bokeh the way we always used to in the 1970s and onwards, from the days of the first Minolta RF lenses - enjoy it!

mallardblue-mirror.jpg (269.32 KiB) Viewed 4707 times

This is why I am unlikely to sell my 500mm RF. Like my 16mm fisheye, it has a function.
David

[InTheSky]

I really like the donut's in the picture.

For me the donut's effect has never been a problem with the lens, I was more to be able to have a sharp picture from it ... This is what I'm working on for the moment.

And I'm agree with the Minolta 16mm 2.8 ... This lens has to stay in the bag or some place available when it is time to really use it.

Your explanation about the vignetting and the flare has rang me a bell ... On the Lens There is this strange hood that we can remove from the 500mm reflex lens ... At first when I got my first lens in my hand past years ago I was not sure If this part of the lens needed to be removed ...

It's look like if Minolta knows the problem ... and tried to offer and alternative to put custom hood that can screwed at the closeness of the front element. Unfortunately with my actual lens no paper or user manual has come with it (low price ). But, I was wondering if anybody has this user manual in hand an can check if they telling something about this detachable hood.

I'm thinking that probably making a paper hood in kind of conic shape can probably solve the flare and the vignetting at the same time ... Food to talk when I will get the time to do the test. For the moment I need to go downstairs and finish my basement for the baby's coming room .


Regards,

Frank

[InTheSky]

There is way when controlling to situation to have at least no trace of donuts too ...





For bigger picture : (with the A700) : http://www.pbase.com/nadeauf/image/9684 ... iginal.jpg

A+

Frank

[NevHi]

And I'm agree with the Minolta 16mm 2.8 ... This lens has to stay in the bag or some place available when it is time to really use it.

I like mine, especially to take cloud pictures.

But, I was wondering if anybody has this user manual in hand an can check if they telling something about this detachable hood.

The Sony two sided 'manual' (Part 2685148110) that came with mine says two things about the hood.

On a diagram of Names of parts it has
9....Lens Hood

and
in another section

To attach the front lens cap
Always attach the front lens cap with the hood attached.

It looks like the hood is made to be always on. Mine has never been off. The black "rubberised" insulation [~3.5" or ~9cm] diameter used for pipes and refrigeration could be slipped over the end as an extended sunshade/hood, as could polystyrene "bottle coolers" etc.

[InTheSky]

Thanks !

Frank

[Chris Malcolm]

I have the Sony version, which has a big fixed lens hood, or at least very hard to remove

I understand this kind of lens is inherently low in contrast and soft in detail. If I boost contrast and sharpness a lot the results start looking like the images from my other lenses. It's very sensitive to exact focus. My A350 slightly back focussed with it, an effect that was only perceptible on one other lens, my 50mm f1.4 at its widest. Correcting that very slight back focus by adjusting the A350's AF sensor plane sharpened up the 500mm reflex images a lot.

It's also very critical indeed of atmospheric seeing conditions and camera shake. At shutter speeds below about 1/300th sec mirror slap intrudes and starts to smear the images, and possibly some shutter slap too. If the sun is shining any shot over about 100 metres is likely to be softened quite a bit by thermals, and quite likely even if the sun is obscured.

It took me quite a while to learn how to get good vivid sharp results from it. I would have decided all the bad rumours about the lens were true were it not for the fact that every so often it would pull off a very nice sharp shot. That proved that the lens was capable, so I just had to find out what other factors were usually spoiling its performance. Now that I know how to get the best from it I'm very happy with it. But I haven't a long refractor to compare it with.

Here's examples of the kind of results I get from it. For a higher resolution version click on the URL below each image.



http://farm4.static.flickr.com/3464/389 ... 0ec4_o.jpg



http://farm4.static.flickr.com/3594/360 ... cb70_o.jpg



http://farm3.static.flickr.com/2695/402 ... bc28_o.jpg

[Mark K]

Very nice. Sony salesman talked me into 70-400G but ....your samples say otherwise