Cameras with removable lenses

[melev]

I have a question about those lenses people put on their Nikon or Canon cameras, esp. DSLRs. What numbers are you looking for for Macro mode? What about normal mode and then Zoom for those shots of the Grand Canyon?

The numbers in millimeters never make sense to me. What are the standard sizes?

 

[Blazer88]

Most people seem to use the 100mm'ish focal length for macro's. The minimum focusing distance, where you get the most magnification, is about 6" on the Canon which is very useable for aquariums. I plan on getting the Sigma 150mm macro but the minimum focusing distance is about 18", I will have to use extension tubes to bring the focus point closer (which means more magnification) or stand further back from the subject. The higher the mm number the more "zoomed" in the lens will be. For Grand Canyon shots, I would take my 10-20mm ultra-wide angle to fit as much scenery in the frame as possible. My "everyday" lens in a 24-105mm.

 

[BlueCorn]

I cover 12-700mm with the lenses in my bag. On top of that my sensor gives me a 1.6x effective magnification so I actually cover 19 - 1120mm.

For macro, to really be macro, the lens needs to be able to do 1:1, lifesize, magnification. What that means is that the size of the image on the sensor is the same size as the item in real life. I use my 100 f/2.8 for that.

For "normal" shooting I have a 24-70 f/2.8 that lives on my camera most of the time. I also use a 70-200 f/4L and a Tokina 12-24 f/4 for landscape work. If I really want to get in tight I have a Tamron 200-500 and a 1.4 Tele-convertor.

 

[melev]

So a standard range is 24 - 70mm, and if the number is higher then it is better suited for Macro mode? From the responses so far, it doesn't seem like there are ranges.

I looked up a little info on dpreview and looked over gho's tutorial on lenses, but didn't see anything that I could understand and memorize.

 

[jwedehase]

The "higher number" is simply more zoom, Marc, and not related to macro. As an example, Canon has macro lenses in 60mm, 65mm, 100mm and 180mm focal lengths. Beerguy's 700mm is exceptionally long (lots of zoom) and not extremely useful beyond sports and wildlife photography. On the other hand, the 24-70 would be pretty worthless for shooting a bear from across a meadow.

I shoot a 28-135mm on my Canon. It's my primary lens, the lens I use about 98% of the time (until I can afford that same 24-70L that Beerguy uses). I also have a 100-400mm zoom that I use at the race track, the zoo, and stuff like that, but it's a very soft (not sharp at all) cheap lens. When it comes to macros, I borrow a club member's 100mm f/2.8 macro, the same lens as mentioned above.

My goal "set" of lenses is:

Canon 16-35mm f/2.8L
Canon 24-70mm f/2.8L
Canon 70-200mm f/2.8L
Canon 100mm macro f/2.8

As a side note, the "L" in some of Canon's lenses stands for "Lots of money for the nicest glass you can buy."

 

[Blazer88]

The word macro doesn't really relate to the focal length of the lens. The term macro is generally defined as 1:1 magnification. 1:1 magnification means whatever you are taking a picture of will appear the same size on the camera's sensor. I know that sounds weird, but maybe this will help explain. The Canon 30D has a 22.5 x 15.0 mm. You can take a picture of a zoathid that same size and it would "fit" on the sensor and fill it. The difference is at what point the lenses will give you the 1:1 magnification. I know the 100mm gives 1:1 at about 6", and the 180mm is closer to 15". The higher focal length won't give you any more magnification, you just don't have to be so close to get 1:1 magnification. I'm sure I'm confusing the hell out of you know, lol. Hopefully the wikipedia link will help clear things up.

http://en.wikipedia.org/wiki/Macro_photography

 

[Frisco]

maybe this will help sort out some of the basics about focal lengths in a more tangible way:

http://www.usa.canon.com/app/html/EFLenses101/focal_length.html

 

[melev]

I guess it is clear why I don't get this topic. There seems to be no simple answer to my question.

I do understand about the 1:1 ratio, and that the f/stop should be around 2.8 to get the proper depth of field. My problem is that people contact me asking me what camera I recommend, and even worse what lenses. A friend of mine called me from the store telling me exactly what he liked, and I looked it up on dpreview while he waited. it was highly recommended on that site, and I reviewed both the pros and cons of the camera.

However, I didn't have a clue what lenses were good, nor if the ones included would give him some good macro shots or not. Had I told him you need "100mm" or whatever, I think that would have been a tad more helpful.

Using jwedehase lens wishlist does help if others can confirm that is the number they'd look for: 100mm macro f/2.8

http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=155&modelid=7400

That one isn't cheap btw. It is slightly less than what I paid for my camera a few years ago. And I see that the closest you can get to the subject is 5.9" and still be able to focus. My own camera lets me get within 1 centimeter of the object, something I've always appreciated. Mine seems to be 35mm to 210mm with its built-in lense.
http://www.dpreview.com/reviews/fujis602z/page2.asp

 

[StCraft]

jwedehase - Why not this lense ?
EF 24-105 f/4 IS (L)
is it better then the
EF 24-70 f/2.8 (L)

I guess the answer come with that question : Are you shooting outside or inside...

 

[Blazer88]

StCraft, I was trying to decide between those two lenses and I went with the 24-105L for a few reasons. One, I didn't think I would need the F/2.8. The 24-70 would be a better, quicker, lens for freezing motion but I thought the IS would be better for me as I generally take pictures of non-moving objects. Plus I will be doing lots of travel and the 24-70 is not a small and light lens by any means, the 24-105 looked to be a better lens for travel/hiking with.

 

[jwedehase]

StCraft, sure 'nuff, it's the aperture. I may not need the 2.8, but I'd just like to have it there. It does look, however, that the longer lens could make up for it with the IS. This is the same reason I think I'd choose the 16-35 over the 17-40 f/4. I've used the 17-40, and it's downright awesome. It's also reported to be sharper than the 16-35. Realistically, in both cases, I'm not actually decided yet.

But so many shots I've seen with the 24-70L are some of the best shots I've ever seen.... so sharp! And there's just something cool about having the f/2.8L lineup.

Marc, again, the 100mm is the amount of zoom. Your current camera lets you get within 1cm of the subject. The Canon 100mm will let you take that same close-up from 5.9" away because it's that much zoom. Unfortunately focal lengths between SLRs and point-n-shoots don't equate, so there's no real way to compare those numbers.

Also, 2.8 doesn't necessarily give you the best depth of field. In fact, that's a very shallow DOF. While this often works beautifully, it's not necessarily "the best." I shoot at f/8 a lot, as an example, specifically to pick up more DOF.

And.. please don't equate 100mm with macro-ability. It just so happens that Canon has the one of the most famous macros out there, and it happens to be a 100mm lens. It's purely coincidental, and macros can be had at any focal length.

 

[melev]

So I remain confused. Today I went to see the Olympus camera that my friend bought, and tried out both lenses while I was there. The camera worked, and of course I'd need more time to understand how it was set up but overall I wasn't all that impressed with the results.

I guess the lenses he got weren't as good as what I'd need.

 

[TheVillageIdiot]

<a href=showthread.php?s=&postid=9413416#post9413416 target=_blank>Originally posted</a> by melev
So I remain confused. Today I went to see the Olympus camera that my friend bought, and tried out both lenses while I was there. The camera worked, and of course I'd need more time to understand how it was set up but overall I wasn't all that impressed with the results.

I guess the lenses he got weren't as good as what I'd need.

Some of my thoughts about Macro...

1:1 ratio is acheived at the minimum focal distance of the lens, i.e., the closest the front element of the lens can get to a subject and acheive focus on the camera film or sensor.

There are many different focal lengths that can acheive a 1:1 ratio, but they all acheive it a different min. focus distances. The smaller the mm number, the closer you have to be to your subject to get a technical macro shot.

We'll use sigma's standard macro lineup as an example because they have quite a few 1:1 lenses... (MFD = min. focus distance)

50mm f2.8 - MFD 7.4"
70mm f2.8 - MFD 10.1"
105mm f2.8 - MFD 12.2"
150mm f2.8 - MFD 15"
180mm f3.5 - MFD 18"

There are other lenses that are called "Macro" but do not achieve a 1:1 ratio at any focal distance. As you can see from the lenses above, each one acheives 1:1 ratio but as your focal length increases, the further away you have to be to get a shot in focus.

In other words, w/ the 50mm on your camera, if you take a picture at 7.4" away of a coin and do the same with the 180mm at 18" the coin will print out (in both shots) at exactly the same size on a 4x6 print. At least, that's how I understand it...

hth,

Matt

 

[TheVillageIdiot]

A quick addition, for comparison, canon's f1.8 50mm lens has an MFD of 18" (same as the 180mm) but w/ out the additional 130mm, it can only achieve a magnification ratio of 1:6.6...

 

[kryppy]

This thread reminds me why I love P&S cameras.

 

[kwl1763]

Marc, granted I'm a newb to DSLR but I'll try to explain and Blazer et al with way more knowledge feel free to correct!

Macro means 1:1 or more plain and simple

Minimum Focusing Distance is more a function of the lens and has nothing to do with macro (except that in taking macro shots your usually close so you want a close focusing distance)

The mm you see as others have mentioned are zoom numbers. "Normal" film day cameras were 35mm (remember that number?) So larger numbers mean you fit less in the frame (zoom in more) and smaller numbers more in the frame (zoom out more)

Fixed focal lengths (say a 100mm) lens always has the same amount of "stuff in them" you can only zoom in and out by moving the camera. The only adjustment is a focusing mechanism

When you see 28-105 or 17-85 etc it means the lenses can zoom in or out to those levels.

For Grand Canyon shots it depends what you want to do. for panoramic landscapes your going to want a wide angle (low mm) If you want to really zoom onto widelife, the river, whatever you need a high zoom telephoto (say 300mm or greater)

So for the aquarium. A good macro ( I have the 100mm 2.8 myself) is all you'll need. The nice part is with 10MP cameras the images are so big you can "zoom by crop" In other words the pic comesout as a whole coral but you crop to just one branch and still have a nice big 6 inch picture. (or you could simply resize the huge one of the whole coral and get the "full shot")

This would be an absolute pathetic walk around lens though. You would find that it would be hard to get enough in the frame when close, no zooming ability, etc, etc.

Now ideally we would want a say 15mm-700mm lens. That just doesn't exist so you have to chose a couple. One for everyday stuff should be somewhere in the 15-100 (or 17-85, or 18-55, you get the point, somewhere in that range) zoomable and if you need/want a telephoto (big time zoom) go to 200 or 300 or 700 or whatever.

And yes lenses are the expensive part. In fact it's the difference. Basically all the DSLRs are very good, it's the lens that makes the difference.

Also on the f-value. It has to do with speed/quality of the lens. An f1.8 lens can have a very large aperature (small f-stop) and therefore a high shutter speed when compared to say a 4.8f lens. Shooting fish this is super important and for the macro you don't want less then 2.8 and if you can afoord it a 1.8. Now you can do other things like increase ISO and such to buy you some speed also. Larger f-stops translate into more depth of feild also. So if you need a whole coral in focus an f-stop of 2.8 wouldn't work. you would need probably and f/8 or higher (see the difference, in fish you care about speed (to freeze the motion) of shot so we want the lowest possible DOF because we only care about the fish and not what's behind him, here we don't care about speed (coral is not moving) but need to get the DOF correct to see all the coral . But three things are always related. The f-stop, the shutter speed, and ISO. A larger depth of field (more of the image in focus) means a longer shutter speed. And ISO can let you "buy back some speed or DOF by increasing it but at the expense of introduced noise) So those things come into play on every single shot not matter what and there is not such thing as the best f-stop, etc. It depends what you need to get done.

Anyway enough of my newbie rambling but that should help.

 

[TheVillageIdiot]

<a href=showthread.php?s=&postid=9417762#post9417762 target=_blank>Originally posted</a> by kwl1763
Marc, granted I'm a newb to DSLR but I'll try to explain and Blazer et al with way more knowledge feel free to correct!

Macro means 1:1 or more plain and simple

Minimum Focusing Distance is more a function of the lens and has nothing to do with macro (except that in taking macro shots your usually close so you want a close focusing distance)

1:1 magnification is achieved at only one focus distance, the closer you get to your subject w/ a fixed focal length lens, the larger the magnification of that subject. I'm pretty sure that you are only acheiving 1:1 on a macro lens at or near the Min. focus distance. At least, that's what I've always assumed, I have never tested a 1:1 lens to find out...

I.E., w/ the 180mm f3.5, if you take a picture of a coin at 18", the coin is represented 1:1 on the film or sensor.

This is why we use bellows or extension tubes that allow the lens to focus even closer to the subject than it normally does and thereby achieving a higher magnification ratio than before, and also why many extention tubes don't work on lenses less than 50mm because the MFD would be pushed past the front element of the lens...

does that make sense?

 

[melev]

Actually it makes a lot of sense, and Keith's post helped me the most. Thanks for taking the time.

Keith, what are you going to do with your old camera? I'm probably going to buy another one off Ebay when this one quits, since I'm so comfortable with it and it does what I need.

 

[kwl1763]

Sell it, let me know if your interested.

 

[melev]

Sure, as long as it isn't too salty. You know how to find me.