PDA

View Full Version : 30mm macro?



winjeel
07-02-2009, 03:28 AM
I've seen the news that Sony has a 30mm macro lens either coming out or came out. But, I can't help but wonder, what would you use it for? To me, long the better, not wider! :confused:

Ian Grant
07-02-2009, 05:24 AM
Depends what format it's being made fore, Sony don't make film cameras, 30mm on the Sony SLR's would be the digital equivalent of a 50mm macro lens on 35mm.

Macro lenses come in various forms and it really depends what's being photographed, some are longer than a standard lens 80/90mm, others 50/60mm, while for more extreme close up they can be shorter still 28mm/40mm, any shorter and they tend to be called Micro lenses. I've used an 8mm Micro lens on a Pentax for scientific work.

Ian

wayne naughton
07-02-2009, 06:58 AM
30mm on a full frame A900 would be 30mm, Ian....

xtolsniffer
07-02-2009, 08:17 AM
The shorter the focal length, the more magnification you get for any given length of extension. I use Zuiko 20 and 38mm on bellows, the working distance is very very small, but the magnification is very very high.

Anon Ymous
07-02-2009, 08:26 AM
30mm on a full frame A900 would be 30mm, Ian....

This lens will be 30mm on the full frame A900, but will give you a round picture. It's an APS lens, just like there are Canon/Nikon lenses specifically for APS cameras. The equivalent to 135 is 45mm IIRC.

Ian Grant
07-02-2009, 08:58 AM
30mm on a full frame A900 would be 30mm, Ian....

Only when the 30mm is designed for a full frame camera :D

The APS version may still be usable on a full frame on extension tubes/bellows as coverage increases as the extension is increased.

Ian

wayne naughton
07-02-2009, 09:27 AM
Whoops.... my mistake..... grin.

Q.G.
07-02-2009, 12:12 PM
No mistake.
A 30 mm is a 30 mm is a 30 mm. No matter how small or large the format, and not matter whether it fills that format or not.

Especially when macro is concerned, a lens' focal length matters more than an angle of view.
Try to do 1:1 with a 1200 mm lens. Very, very hard. No matter whether on APS or on 8x10".
Try to do 10:1 with a 30 mm lens. Easy! On APS, Full frame 35 mm format, MF, LF.

winjeel
07-02-2009, 08:34 PM
Actually, slightly off topic, but thinking about the difference between APS-C and 35mm, has there ever been any APS-C (film) slr's made? If not, why not?

DWThomas
07-02-2009, 08:48 PM
Actually, slightly off topic, but thinking about the difference between APS-C and 35mm, has there ever been any APS-C (film) slr's made? If not, why not?

Yes there were several, but they never quite caught hold, partly I suspect because the full array of films available for 35 mm never made it to APS.

DaveT

Q.G.
07-03-2009, 06:54 AM
Partly too, because 35 mm already is very small, and APS was just too small to deliver quality. Too small to appeal to people who would buy SLRs and not just P&Ss.

And that will be behind not all films making it to APS format too.

polyglot
07-03-2009, 09:13 AM
As has been pointed out, it's an APS lens and will not cover a 135 frame. As to the original question, wider macros are useful when you want to get some perspective effect into the shot rather than flattening everything in the scene. Clearly it's of little to no use shooting insects, but if your subject won't run away then it can be a good effect.

The wider perspective means that with a small subject (hey, it's a macro!), the distance between the camera and subject better matches the scale of the item being photographed and as a result, the item can look larger and/or more natural than it would with a longer lens.

If you want that effect on 135, may I recommend the CZJ Flektogon 35/2.4? It goes to 1:2 without tubes, has great sharpness and lovely bokeh.

Q.G.
07-03-2009, 09:22 AM
As has been pointed out, it's an APS lens and will not cover a 135 frame. As to the original question, wider macros are useful when you want to get some perspective effect into the shot rather than flattening everything in the scene. Clearly it's of little to no use shooting insects, but if your subject won't run away then it can be a good effect.

It has also been pointed out that:

1) It will cover 35 mm format, even larger formats, when you use it for what it is meant to be used.

2) that being 30 mm does not make it a wide angle lens.
Angles of view change with lens to subject distances.

The purpose of making close-up lenses short is to avoid huge amounts of extension.
I'm very happy with my 16 mm lens, because i would hate to have to figure out how to get to 10:1 using an 80 mm lens.

But 'wide angle"? Where? How?
;)

polyglot
07-04-2009, 09:45 AM
It will not cover 35mm format unless you put long tubes on it - the image circle is simply too small. If you put tubes on it long enough to cover "any other format", the focus point won't be outside the lens. Doesn't matter how much you love your 6x6 QG, this lens will either not cover your format or it will do so with the focus point being inside the lens body. It's not even certain you could cover 135 with it unless you use a teleconverter, which makes it a different lens.

30mm is quite wideangle compared to the 100mm and 180mm macros typically seen on DSLR systems, which is what this lens is designed for. The OP asked "why so wide?", which is a perfectly reasonable question because reduced working distance is generally seen as a negative. 30mm is the shortest macro ever made for the Alpha system.

Q.G.
07-04-2009, 11:18 AM
Where the focus point is depends on the lens design.
It may get so close that it touches the glass, or even is inside the glass.
But is it? I don't know the design of this lens, so cannot tell.
But i bet you it will easily cover even larger formats than 6x6 and not have any problem with the subject being inside, instead of in front of the lens. ;)

If you base your assumption not on knowledge of the lens's design, but on the believe that you can get too close, then know that there are many short macro lenses lenses that go to magnifications high enough to even cover LF, and still leave room between them and the subject.
It is not a fundamental impossibility.

APS format varies between 1.2 and 1.7 times smaller than 35 mm format. Sony's version is 1.5 times smaller.
So if this lens covers APS C at infinity, it will cover 35 mm format fairly rapidly when focusing closer.
I'm too lazy to do the sums to figure out at what focussing distance or image scale.
But, it will certainly do so at 1:1. Not very extreme for a macro lens. Certainly not for a short macro lens (as mentioned, short macro lenses are made short, not to provide a wide angle view, but to make getting a decent magnification easier. So we can safely assume that 1:1 is not very extreme for this lens).


So i think that the answer still stands: this short to allow decent magnifications.

The same reason, for instance, Olympus (the 'champion' of photomacrography) brought out 21 and 35 mm lenses.
Those, by the way, also work great on larger formats.

dougjgreen
07-05-2009, 12:31 AM
Actually, slightly off topic, but thinking about the difference between APS-C and 35mm, has there ever been any APS-C (film) slr's made? If not, why not?

Yes - APS stood for Kodak's Advanced Photo System format. I know for a fact that Nikon marketed a family of APS SLRs called Pronea, and Minolta marketed a family of APS SLRs called Vectis-S. Canon marketed an APS SLR called the EOS IX.

In fact, you can still buy these cameras on ebay. There is actually some compatibility between the Nikon and Canon APS SLRs and their current lens mounts. Nikon's family of F-mount lenses mount on Proneas, and Canon's EOS mount lenses mount on the EOS IX.

These SLRs sell for prices in the $20-80 range on ebay nowadays. I have no idea what the availability of APS film is currently.

winjeel
07-06-2009, 10:21 AM
Thanks, all. I'm a little wiser. :)