18-55mm kit lens macro limitation?


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Gengh

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May 6, 2007
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#1
Hi, as a new DSLR user, I would like to check with kit lens users, that I haven't got this wrong.

Is the 18-55mm kit lens not suitable for close ups and macros at 55mm and large apertures?

I've been shooting the random bug that wanders into my home, but I always end up disappointed with the fuzzyness of the pictures. Friends have advised me to use a smaller aperture, so that it's easier to manage the DOF (they thought it was a focusing problem). But I kind of like the shallow DOF effect. So today I decided to test things out. I shot close ups of my watch and a DVD box at 55mm and various aperture sizes, with my K100D sitting flat on the table, and this is what I see (these are 100% crops):

Watch at f5.6


Watch at f6.7


Watch at f8


Watch at f9.5
 

Gengh

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#2
DVD box at f5.6


DVD box at f6.7


DVD box at f8


DVD box at f9.5


It seems that at f5.6 the sharpness is just not there, at f6.7 it gets better, and only from f8 onwards do the pictures seem really sharp. Has anyone else noticed the same effects in their pictures?

I know that the kit lens would have its limitations (in fact I'm sure all lenses do), but I just want to confirm that this is one of them, and not just me doing something wrong. In fact, at for things further away (eg. portrait) 55mm f5.6 works fine.
 

kcuf2

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Dec 29, 2005
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in general, lens do not perform at their best wide open, in your case f5.6 at 55mm.... lens sharpness, contrast etc. then to improve when u stop down the apeture to arnd f8 or f9.
one of my previous lens need to go till f11 or f13 before tt sharpness kicks in.

there's nothing wrong with ur lens. That is why people pay a premium for the pro grade lens. eg. a few thousands for those 70-200mm f2.8 lens, 85mm f1.4, 500mm f4 etc. etc. because these lens are able to give very sharp and good colour pics wide open at f2.8 or f4 respectively...
 

longko

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Sep 7, 2006
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#4
The kit lens is not a macro lens, nor does it have macro function. It allows you to take close-ups only to a certain extend. To get a sharp image, you need a step down to get better Depth Of Field (DOF). My macro shots using a 1:1 macro lens, are often taken with f11-f16.

These are few ways to make your kit lens take macro shots;
1. Extension tube
2. Close-up filter
3. Reservse lens
4. Macro converter

If you like to take macro shots I suggest that you either invest in a true macro lens (Tamron 90mm Di, Pentax FA 100mm, Sigma 105mm) or a zoom lens with macro function (Sigma or Tamron 70-300mm 1:2 macro). You'll need external flash too for those narrow aperture.
 

creampuff

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Jul 11, 2006
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#5
Ahh bro, now you're starting to discover the limits of the kit lens. The kit lens is a starter lens with a focal length that covers everyday picture taking. It's also a variable aperture design, so when you're at the longest focal length, your maximum aperture drops to f5.6.

From your pictures, you've just shown the physics of optics. Lenses aren't as sharp at maximum apertures as when they are stopped down with the optimum sharpness somewhere in the middle between the largest and smallest apertures. That apparent sharpness is also helped by greater DOF when we stop down to a smaller aperture.

Like bro longko (aka Mr Macro :bsmilie: ) has suggested, if you want to take close-ups, there are other options available. IMO your best bet is to use a cheap 50mm lens (can be a manual focus) with an extension tube instead of the kit lens for the occasional close-up.
 

night86mare

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Aug 25, 2006
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#6
Cannot use to take macro la, focusing distance is too short. You can either choose to crop massively or end up with very very huge pictures where your "macro" subject is way too small in the frame.

Another point is that if you use true macro lenses or zoom macro lenses, you can focus much better since you can see the details in your viewfinder. When the say, dragonfly's eyes are a small little dot on your screen, you can't really tell whether it is in focus, can you?

-But- the kit lens can take certain larger creatures like dragonflies, etc.. Not impossible, just have to crop massively, here are some I 've taken with my kit, won't really call them macro, more like closeup :dunno: In any case, the kit lens is obviously not the best of lens, though Pentax kit lens is better than most other brands, from what I've seen.





Mmm, and if budget is your concern you can get the Tamron/Sigma 70-300 macro zoom lenses, both are pretty bang for buck! =)
 

Snowywolf

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Apr 21, 2007
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#7
Cannot use to take macro la, focusing distance is too short. You can either choose to crop massively or end up with very very huge pictures where your "macro" subject is way too small in the frame.

Mmm, and if budget is your concern you can get the Tamron/Sigma 70-300 macro zoom lenses, both are pretty bang for buck! =)
i wan the 70-300mm..........
actually.. tamron 90Di is very good for a starter..
:thumbsup:

wana go for any shoots in the west today, nightmare?
 

night86mare

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#8
i wan the 70-300mm..........
actually.. tamron 90Di is very good for a starter..
:thumbsup:

wana go for any shoots in the west today, nightmare?
Hahaha, I wish I could, but I'm stuck at home, have a trip starting tomorrow so have to prepare.

When I'm back! =)
 

Gengh

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May 6, 2007
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#9
Thanks a bunch guys, that puts me more at ease, and I've tried again on a moth at f11 and gotten much better results than before. :D I guess I was just expecting too much of the lens before. And I've paid a bit more attention to the exif of the macro photos I see around, the apertures are not as wide open as I thought I needed them to be. Lesson learnt. :embrass:

Not planning to buy new lenses yet, but a 50mm is probably something I'll get eventually. Hope you guys can help me make a more informed choice here:

1. If I get a 50mm macro lens (either Pentax or Sigma), will it be good for non-macro stuff such as portraits and even scenery, or will a normal 50mm lens (one without the macro label) be clearly superior for such shots?

2. If I understand correctly, I can use a 50mm extension tube with a normal non-macro 50mm f1.4 to get a setup equivalent to 100mm f2.8. But how would this affect the maximum and minimum focusing distances of the setup? And at best (with what Pentax and Kenko has) I retain auto aperture control, but not auto focusing right?
 

creampuff

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Jul 11, 2006
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#10
Thanks a bunch guys, that puts me more at ease, and I've tried again on a moth at f11 and gotten much better results than before. :D I guess I was just expecting too much of the lens before. And I've paid a bit more attention to the exif of the macro photos I see around, the apertures are not as wide open as I thought I needed them to be. Lesson learnt. :embrass:

Not planning to buy new lenses yet, but a 50mm is probably something I'll get eventually. Hope you guys can help me make a more informed choice here:

1. If I get a 50mm macro lens (either Pentax or Sigma), will it be good for non-macro stuff such as portraits and even scenery, or will a normal 50mm lens (one without the macro label) be clearly superior for such shots?
Yes, a 50mm macro is versatile enough to be used for general, non-macro shooting. Obviously it doesn't have the low light edge of a standard 50mm (between 1 to 2 and a half stops slower in maximum aperture) and focusing may be a little slower (longer focus travel from infinity to min focus & slower max aperture), but it's versatility is where it shines. Where most standard 50mm lenses focus down to 0.45m, the 50mm macro's closer focusing and superior sharpness allows you to shoot a lot of subjects up close. Macro lenses are optimised for flat field reproduction which means you can shoot objects like posters/documents, people's faces up close without the curvature distortion that creeps in when compared to standard 50mm lenses. Most 50mm macro lenses today are f2.8 which isn't too bad but you won't get the very thin DOF, background completely out of focus kind of shots at regular focusing distances of the 50/1.4 or 1.7 unless you're shooting up close.

2. If I understand correctly, I can use a 50mm extension tube with a normal non-macro 50mm f1.4 to get a setup equivalent to 100mm f2.8. But how would this affect the maximum and minimum focusing distances of the setup? And at best (with what Pentax and Kenko has) I retain auto aperture control, but not auto focusing right?
An extension tube reduces focusing distance and increases image magnification. but it doesn't double your focal length. You will need a 2X teleconverter for that instead. To my knowledge, there isn't any extension tube for Pentax that allows for AF. If you want AF, get a macro lens with AF (essentially a 50mm with a helical extension tube). If you're shooting macro, you'll need to get used to... manual focus.
 

longko

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Sep 7, 2006
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#11
It really depends on what kind of macros you are after. Here's a guide on which focal length to get;

50 or 60mm - Products (still life) & flower photography
70mm - Very slow moving insects (some of the bettles) or snail
90mm, 100mm or 105mm - Slightly active insects like spiders, dragonflies, ants
150mm, 180mm or more - Very active insects like butterflies or bees

Using an extension tube, reverse lens, close-up filter/lens will means you cut down your working distance by a lot. Unless you are used to macro photography or want make life difficult for yourself, a true macro (1:1) or zoom lens with macro (1:2) would be a better bet.

Pentax 50mm f1.4 is about $315+
Pentax 50mm f2.8 macro is about $400+
Tamron 90mm Di f2.8 macro is about $580+
Pentax 100mm f2.8 macro is about $700+
Sigma 105mm EX f2.8 macro is about $580+
Sigma/Tamron 70-300mm with 1:2 macro is about $280+ (Can't expect sharpness as a prime lens)

If you don't mind MF, you can get a legendary new (old stock) Vivitar 105mm f2.5 macro made by kiron for US$215 (w/shipping) on ebay.;)
 

Snowywolf

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Apr 21, 2007
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#12
It really depends on what kind of macros you are after. Here's a guide on which focal length to get;

50 or 60mm - Products (still life) & flower photography
70mm - Very slow moving insects (some of the bettles) or snail
90mm, 100mm or 105mm - Slightly active insects like spiders, dragonflies, ants
150mm, 180mm or more - Very active insects like butterflies or bees

Using an extension tube, reverse lens, close-up filter/lens will means you cut down your working distance by a lot. Unless you are used to macro photography or want make life difficult for yourself, a true macro (1:1) or zoom lens with macro (1:2) would be a better bet.

Pentax 50mm f1.4 is about $315+
Pentax 50mm f2.8 macro is about $400+
Tamron 90mm Di f2.8 macro is about $580+
Pentax 100mm f2.8 macro is about $700+
Sigma 105mm EX f2.8 macro is about $580+
Sigma/Tamron 70-300mm with 1:2 macro is about $280+ (Can't expect sharpness as a prime lens)

If you don't mind MF, you can get a legendary new (old stock) Vivitar 105mm f2.5 macro made by kiron for US$215 (w/shipping) on ebay.;)
greattt advice..
now's the tricky part..
to save enuff $$ and SPEND on the lenses..:confused:
 

longko

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Sep 7, 2006
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#15
You have been warned. :bsmilie:

Sadly, there is no cure for it.:cry:
There's a cure, it's call go broke.:bsmilie: It's like my ears, my doc said that the only way I get cured is when I go deaf:bsmilie:
 

Snowywolf

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Apr 21, 2007
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#17
There's a cure, it's call go broke.:bsmilie: It's like my ears, my doc said that the only way I get cured is when I go deaf:bsmilie:
hahaha....
tt's very very corny...:thumbsup:
upppss for the joke of the day...

eh.. for LBA right.. the only way to curb it..
is for one to go 'blind' which i think none of you guys want it to happen right?:sweat:
-laughs-
 

longko

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Sep 7, 2006
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#18
hahaha....
tt's very very corny...:thumbsup:
upppss for the joke of the day...

eh.. for LBA right.. the only way to curb it..
is for one to go 'blind' which i think none of you guys want it to happen right?:sweat:
-laughs-
Eh... What my doc says is true leh... I'm deaf on high pitch cause there's a constant high pitch sound in my ring (like ringing sounds in the ear.), this result to my deafness. So if I go deaf, I won't be able to be hear that ringing sound anymore:bsmilie: This is what it happened to my doc's sister:(
 

May 22, 2005
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#19
There's a cure, it's call go broke.:bsmilie: It's like my ears, my doc said that the only way I get cured is when I go deaf:bsmilie:
That's not a cure, it only makes you to want to get out of being broke and buy those lenses!
 

Gengh

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May 6, 2007
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#20
Haha, yes, to fight off my temptations to buy lenses (after looking at all those pretty pictures that are clearly beyond what the kit lens can do) I'm telling myself to buy all the cheap and small things first, like filters (circular polariser, GND comes to mind) maybe.... and play with the kit lens more. Longer term plan would probably be to replace it with a Sigma 18-200mm and one of the 50mm (thanks longko for the list, MSColor quoted me $600+ for the Pentax 50mm macro when I happened to drop by AMK). Just not very sure yet which lens I should prioritise, must see what I end up shooting more of.

Sorry to hear about your ear longko, is your doctor a GP or already a ear specialist?

And hope nightmare is having a good trip! Remember to bring back lots of pictures of beautiful sunrises/sunsets!
 

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