Why do I need a macro lens?

[Stolireef]

I just ordered my first DSLR (was an old school film SLR guy with an AE-1 that I still own). With a film SLR, you'd need a macro because blowing up shots from a longer distance would often cause graininess. But, with a 24 MP DSLR, I would imagine (though I'm no expert at all) that you'd have significant ability to zoom in without needing to get too close for the shot. I'm assuming that if I'm shooting in RAW mode, that I could get a pretty good closeups (granted not 1:1) from a couple of feet away and perhaps a better depth of field.

The only thing I can think of (and again, I'm the resident photog idiot) is that the geometry of the lens might produce some artifacts at the edges.

So, help a DSLR newbie and explain why I'm wrong (and feel free to make fun of me in the process, wife loves reading those posts).

Thanks.

 

[jsker]

I have a 100mm on my wish list, like yourself I know enough to be dangerous. I have had a couple of conversations and seen some of the pictures taken with a 60mm and 100mm lens. I like the pictures with the 100mm

 

[saltyfilmfolks]

A macro lens has a close focus distance. That's the key. Besides magnification, it also allows you to put an object close to the lens.
Grab the AE1 and look at infinity. then set it the other way. It should be about (with a 55mm) about 4 feet. any thing closer is out of focus. SOME lenses naturally have a closer focus and you can fake a good macro shot. (my nikon 35mm manual is abot 1.8 feet. In general this is marked on the lens,

Fwiw my macro is a 1965 minolta 55mm manual focus.

RAW

Now to poke fun at you. (get the wife.)

Raw is a larger color gammut(or range) Similar to film stocks, inexpensive print film has less color and light range than Kodachrome(all hail the chromes!!)
So the only thing you get is a broader color adjustments in post production software.


Now that the wife is gone and laughing, lets go shopping! What camera did you get?

 

[Stolireef]

Thanks for the response. I got the Nikon D3300. Got great reviews by Ken Rockwell. I'm really not looking for professional results. From my film days thought, I know that the glass is key. Plus, I want to be able to take some shots of my son playing tennis.

Oh, and I loved Kodachrome. We just dated ourselves. We lived in Rochester, NY for about 20 years and got the best prices. I even remember when Kodak set up the first scanning kiosks in supermarkets. Then, Fisher came in and said digital photography was a fad and would never amount to anything...Kodak goes bankrupt.

 

[Charles Weller]

RAW files are just the raw sensor data. You need to process them to actually create an image from the file. When shooting in jpg the camera records all of the raw sensor data and then processes the file to create the jpg, after which the raw data is removed. Shooting in RAW format allows you to process the image the way you want it before saving it off a jpg. This process can be repeated as many times as you want, allowing you to create multiple versions of the same photograph. Other benefits include increased levels of brightness, much easier correction for over/under exposed images, adjusting the white balance and non-destructive editing of the image.

As far as needing/using a macro lens, every lens has a minimum focus distance. For example, my 70-200mm lens at 200mm is 4.5 ft. So when I am trying to take a picture of a new coral I have to set up my tripod 4.5 ft away from the aquarium. This prevents me from filling the frame with the coral. If I were to use the Canon 100mm macro lens I only need to be 12" away from the tank allowing me to fill more of the frame. You can use a non-macro lens and then crop the image to achieve this, but you would sacrifice image quality.

 

[Derek]

I use a 100mm and works great. With the 100mm, you don't need to be so close to the coral to have a nice macro pic. If you get a macro lens, you'll need to get a tripod. I have one that can go flat for top pictures.

 

[saltyfilmfolks]

Thanks for the response. I got the Nikon D3300. Got great reviews by Ken Rockwell. I'm really not looking for professional results. From my film days thought, I know that the glass is key. Plus, I want to be able to take some shots of my son playing tennis.

Oh, and I loved Kodachrome. We just dated ourselves. We lived in Rochester, NY for about 20 years and got the best prices. I even remember when Kodak set up the first scanning kiosks in supermarkets. Then, Fisher came in and said digital photography was a fad and would never amount to anything...Kodak goes bankrupt.

One of the nice things about Nikon is you can use the old glass. If you don't mind manual focus. There is a slight difference in the very old glass. The auto indexing needs to be machined. But you can buy them already done for you. Also most later auto focus models will work. There is a slighbdifference in the auto focus drive.
But Ken I belive talks about that too.

 

[QuixoticReefer]

If budget is concern you don't need a macro lens, you can reverse a lens that you have and use it as a macro lens. There are adapter rings sold for this use and other than losing af it is pretty easy to take a really nice macro (btw always use a tripod) ... that being said if budget isn't an issue get a 150-180mm internally focusing macro lens it give you an additional 3-4 inches of focusing range at 1:1 over an 100 mm (use a tripod) and to sum it all up have fun and use a tripod

 

[Stolireef]

I guess I didn't do a good job asking my question. Basically, since I have a high resolution camera, why do I need to get so close to the coral with a macro lens. Can't I shoot from a normal distance and then just zoom in on the image?

 

[saltyfilmfolks]

Get the old camera out and try it.

With the zoom you are getting and the lens you have you will have to stand back 4 feet.

And Kodachrome film has more resolution than your new camera.

But yes. You will still be able to get some pretty good pics.

 

[RamsReef]

You don't.

Say you shoot a subject and lets say you want to shoot a polyp. The polyp will fill x% of your sensor without the macro. With the macro it will fill x+y%. The macro allows you to put more of the subject onto your sensor sort to speak.

Also you will find that as you zoom in you loose focus and the image becomes soft. This is like taking a piece of paper and zooming it into your face until you can't read it, your eyes cant focus anymore.

With the macro you will gain that ability to focus, up close, and fill your sensor.

 

[Holy_makerel]

I guess I didn't do a good job asking my question. Basically, since I have a high resolution camera, why do I need to get so close to the coral with a macro lens. Can't I shoot from a normal distance and then just zoom in on the image?

Yes, you can.....but.... the resolution is what will come into play here even on a 24mp sensor. ISO also plays a part. The higher you have to bump ISO the more artifacts are going to find their way into your image, add a heavy crop to it and you may be disappointed with your results.

Something else to look into for you might be extender rings. These move the glass further from the sensor and decreases the minimum focusing length so you can get closer. Draw back is less light getting to the sensor.

The plus side for your camera is that it is a crop sensor so your focal length is always multimplied by 1.5x(on lenses not specifically made for crop sensor cameras). So if you were to buy a 100mm macro its EFL will be 150mm on that camera.

I shoot a nikon d7200 with both 100mm tokina and 50mm sigma macro lenses.

Good luck and have some fun!

 

[Stolireef]

Now it makes sense. Thanks for the help. Camera arrives Thursday so I'm pretty excited.

 

[dragon99]

So the lens that came with my D5500 (and probably the OP's D3300) is a 18-55mm with a minimum focus distance of only 10-11 inches. Most of the time I can put the lens on the glass and focus on my corals.

So with that in mind is there much benefit still with the 90mm or 105mm macros? Obviously you can fill more of the frame, but 90% of the time I'm posting these pictures online and the resolution is so limited that I don't feel like I'm losing anything by cropping half of the picture out.

 

[saltyfilmfolks]

So the lens that came with my D5500 (and probably the OP's D3300) is a 18-55mm with a minimum focus distance of only 10-11 inches. Most of the time I can put the lens on the glass and focus on my corals.

So with that in mind is there much benefit still with the 90mm or 105mm macros? Obviously you can fill more of the frame, but 90% of the time I'm posting these pictures online and the resolution is so limited that I don't feel like I'm losing anything by cropping half of the picture out.

It depends on the goal of the picture. You can get great ones with a non macro standard zooms..
This is a standard zoom on a Panasonic lumix. In fact where this coral is a 100mm on this 4/3 sensor would been too close, my 55mm actually is.

This is the macro on the same camera

 

[tenurepro]

I guess I didn't do a good job asking my question. Basically, since I have a high resolution camera, why do I need to get so close to the coral with a macro lens. Can't I shoot from a normal distance and then just zoom in on the image?

You can certainly take a picture of a coral with a regular lens - say that coral is 25% of the frame. You can then crop the photo to make a picture where the Coral is low 100% of the frame. Depending on the camera and the lens, the result may be acceptable. But if you where to get a macro lens and cover the whole frame with the same coral, then that picture will have more data and details than the cropped photo with the regular camera.

This shooting 'fake' macro by cropping a non macro image is limited to shooting fairly large objects, because non macro lenses typically have a large minimum focus distance. To give you an analogy. I can easily shoot a monarch butterfly with a typical 50 mm lens - the butterfly will fill about 40% of the frame at the min focus distance. I can crop the picture, lose more than half of the data, but still have it look decent. Now if I want to shoot a regular house fly with the same 50 mm lens, at the minimum focal distance, I would get a picture where the fly is a measly 5% or so of the frame. You can crop around it but the end result would be really awful with little detail and contrast. Now if I put on my 105 mm micro nikkor, then I can take a full frame shot if the fly preserving al of the details and sharpness.

Even for medium size objects, the macro lens - which are typically built with better glass - will have more detail and sharpness than a non macro lens. Macro lenses also have a shallower depth of field, which can be a good thing - say for generating crisp focus on the subject and having a nicely blurred background.

So do you need a macro for shooting your tank; not for most fish and shooting large corals. You can get away with cropping to a point. But if you get a macro, you would be able to take some detailed pics that would otherwise be very difficult with your stock lens

- qualification; been in photography for about 20 years. While I have sold a few pictures and had few more featured on covers, I consider myself an amateur. My kit includes a couple of Nikon dslr bodies; 105 mm micro nikkor, 200 mm micro nikkor, and a bunch of primary lenses

 

[tenurepro]

Ok - I did a super quick demo
Camera Nikon d7000. I didn't do any post pic editing, and I shot jpg

With a 18-70 mm stock lens, set at 70 mm and f11, ISO 800. Here is the closest I could get to my brain coral colony which is 2 to 3 inches wide

So I cropped it and got this

Not bad.

But then I got out my 105 mm micro nikkor and took this shot

Close, but I can see more subtle details in the macro. Look at the mouth of the bottom left polyp by the snail... it's a lot more sharper and detailed.

I also wasn't shooting the macro at the closest possible distance, I could have taken a portrait of a single polyp.

You do get a bit more depth of field with the stock lens. Note that the snail is more in focus with in the cropped stock lens pic vs the macro lens pic.

So in summary, you can get away with cropping medium sized subjects for closeups, you would get better results from a macro. But the differences may be too subtle depending on the application.

 

[Stolireef]

You guys are awesome. Really learning quite a bit. I did take out the AE1 and played with focal lengths. For the time, I had one of the fastest 55mm lenses out there (down to F 1.2). I also played with my zoom lenses and it was an interesting experience. Then again, with the DSLR, I'll be able to avoid burning through very expensive film to get that one good shot.

 

[dragon99]

thanks @tenurepro @saltyfilmfolks

Examples really helped. The macro shots are just a bit sharper.

@tenurepro
On the macro shot of the acan, the DOF is shallower. Is that a result of the different settings (F?) or a result of the lens?

 

[tenurepro]

thanks @tenurepro @saltyfilmfolks

Examples really helped. The macro shots are just a bit sharper.

@tenurepro
On the macro shot of the acan, the DOF is shallower. Is that a result of the different settings (F?) or a result of the lens?

I should have mentioned that I resized all 3 photos to 1500 pix wide to illustrate how the three pictures would look side by side. The original un cropped shots out of the camera are 3000+ pixels wide and about 8.5 mb (I forgot the actually value but bigger than 3k).

When I cropped the acan out of the 70mm lens, the actual size of the crop was 4 mb and the width of 1750 pixels. Compare that to the macro pic of the acan at 8.5 mb and 3k* width. So two pictures with the acan filling the frame but the macro shot has twice the data and is sharper / more pleasing to the eye. If you wanted to blow it up and print it, then the macro pic is certainly the way to go. But if you are going to make smaller for web devices, like my example above, the differences in quality between the two shrink.... just another thing to consider

Re. Depth of field. Normally the bigger the focal length of the camera, the shallower the depth of field. I think I had set both cameras to f11, but the 105mm has a shallower depth of field than the 70mm. I could've shot the macro at f16 but I didn't want to complicate things.

I actually really like the shallow depth of field. Check out this little video of corals in my tank shot with the 105mm micro nikkor on a tripod. Not the best cuts and yes I was manually focusing to get the polyps in and out of the focal plan (-> some camera shake), but you got love what you can do with a shallow depth of field