Macro Lenses?

[Tim H]

Local camera shop has a secondhand 50mm macro lens for a reasonable-looking price.  Since I already have a 50mm f1.4 lens I use for low-light photography, is a macro lens worth getting for close up shots (I model in N)

[Gordon A]

It is worth asking the question over what range from the object will the lens focus.

 

If the shop selling the macro cannot tell you try looking up on the net.

 

The alternative is if you are using a digital camera use your standard lens as close as it will focus, then crop and enlarge the subject.

 

Gordon A

Bristol

[wagonman]

A decent macro lens is always worth having. Apart from the closer focus – generally down to about half life size without extension tubes, or should be – they tend to be sharper/better corrected. I still use an old manual focus Micro-Nikkor on my DSLRs as it's still sharper than most modern lenses.

[ParkeNd]

A macro lens by definition focuses to 1:1 without extension tubes. The term is often misused to describe close focus lenses. At 1:1 the object you are photographing would be reproduced life size on the film/sensor. Useful if you want to photograph tiny model train components like wheels life size. A 20mm lens (35mm equivalent) - 14mm if you use APS-C crop sensors - would be more useful for train layout photography because of its depth of field.

[dasatcopthorne]

A macro lens by definition focuses to 1:1 without extension tubes. The term is often misused to describe close focus lenses. At 1:1 the object you are photographing would be reproduced life size on the film/sensor. Useful if you want to photograph tiny model train components like wheels life size. A 20mm lens (35mm equivalent) - 14mm if you use APS-C crop sensors - would be more useful for train layout photography because of its depth of field.

 

Isn't a 20mm lens on APS-C = 32mm?

[ParkeNd]

Isn't a 20mm lens on APS-C = 32mm?

 

Yes - but that's not what I said.

 

What I said was that a 20mm lens on a full frame digital camera or 35mm film camera is more useful for layout photography than a macro lens. If however you use an APS-C digital camera you will need a 14mm lens for the same field of view.

 

i.e. 14mm x 1.5 (for a Nikon) is 21mm in 35mm equivalent terms. Being pedantic if the 14mm lens was on a Canon then it's effective field of view on an APS-C camera would be 14mm x 1.6 = 22.4mm.

[EddieB]

A couple of comments.

 

At life size (1:1) magnification, the distance from the the subject to the lens is equal to the distance from the lens to the sensor, which is equal to twice the focal length of the lens.  The shorter the focal length, the more cramped the working distance - not a problem with a "flat" subject, but might become problemmatic with layouts and dioramas.

 

While we tend to think that depth of field increases with decreasing focal length (for any given f number), it's generally because when subjects are taken at the same distance the DOF will be greater for the shorter focal length.  However if the subject is shot to give the same image size at different focal lengths, the DOF is roughly the same across the range of focal lengths (obviously the perspective changes).

[ParkeNd]

A couple of comments.

 

At life size (1:1) magnification, the distance from the the subject to the lens is equal to the distance from the lens to the sensor, which is equal to twice the focal length of the lens.  The shorter the focal length, the more cramped the working distance - not a problem with a "flat" subject, but might become problemmatic with layouts and dioramas.

 

While we tend to think that depth of field increases with decreasing focal length (for any given f number), it's generally because when subjects are taken at the same distance the DOF will be greater for the shorter focal length.  However if the subject is shot to give the same image size at different focal lengths, the DOF is roughly the same across the range of focal lengths (obviously the perspective changes).

I'm not sure what that means Eddie - but this photo of my layout was taken on a Nikon D810 full frame camera with an 18-35mm full frame lens lens set at 18mm. No focus stacking used.

 

[alfsboy]

I have always found that the little silver cameras once so popular gave fantastic results  for models on a macro setting .I had  an early Olympus c2000(I think .I took some shots of US brass and  also some wildlife shots on my new Canon 10D DLSR  with a 200 mm F2.8  to my usual  pro  film processor  lab .He had just started digital processing and was gobsmacked at the results  .Both  came out stunningly but the brass shots were great ,sharp and well detailed  and very close up but great depth of field ..He quickly grabbed on to the fact film was on a warning  .I dont think he realised before .I always used a  little silver camera or my  old Canon G5 ,still a favorite camera and obtained when my C2000 died rather quickly  and Warehouse Express gave me a fantastic deal ,for close ups .I usually just use an iphone now as most shots are just for illustration to a customer rather than a "proper " shot .Their ability to take great shots of  tiny models  always amazes me .

[rogerzilla]

The macro setting on a zoom will get you close enough for most model railway shots but distortion is usually terrible and may be noticeable on buildings, tracks etc.  A 55mm Micro-Nikkor is about £100 secondhand if you use Nikon bodies.  Obviously it's more like 85mm on a DX body.  The Micro-Nikkor does half life size and a PK-13 extension ring (also cheap) gives 1:1; but you really don't need to get that close for 4mm scale.

 

Depth of field is always going to be a problem and a compact digicam suffers less in this respect because of its tiny sensor.  The main thing to do is to get the camera at scale eye level, which basically means plonking the camera body flat on the baseboard.  Then everything looks realistic; If you take photos from above it looks like a model or (at best) one of those tilt-shift photos of real life scenes that were so popular a few years ago.