Which Pentax focal length for Macro?

tscip22 · 09-22-2008, 08:59 PM

I am wavering between a 35, 50 or 100 mm focal length Pentax DA macro lens. Which one do you use, and why? I currently use a K10

Ole · 09-22-2008, 09:22 PM

100mm - you need to have some distance from the lens to the subject!

Wheatfield · 09-22-2008, 10:38 PM

Up until a month ago, I would have agreed 100% with Ole. I just returned from the annual hauling of the trailer. Something I noticed with my flora pictures was that I could have used a standard focal length macro really effectively, and would have had a nice walkaround lens as well.

However, I did shoot some really wonderful macros of some of the various mushrooms that were erupting all over the place, and found for this that the 100mm focal length was still the best.

So now I only agree with Ole 84.693%

innershell · 09-22-2008, 10:48 PM

If it will fly away and get scared easily, get the 100mm. Otherwise, any of those lenses will work. I got my 90mm simply because bugs don't like a big piece of glass near their face.

Venturi · 09-22-2008, 11:00 PM

I've got the Tamron 90mm and absolutely love it as an all around macro lens. But if you're going to get serious about shooting macro there's more to consider than merely how close you are from the subject.

DOF plays a huge part in macro photography. For example at f/16 and 6 inches from subject:

50mm yields a DOF of 0.16 inches
100mm yields a DOF of 0.02 inches

So the subject matter and light can drive your focal length requirements quite a bit. Flash and/or ND filters can even things out but they are not always available or feasible for the shot.

Venturi · 09-22-2008, 11:09 PM

Corrected my numbers above. did calculations on inches but had feet in my head.

tubadad · 09-23-2008, 04:35 AM

Originally posted by Wheatfield

Something I noticed with my flora pictures was that I could have used a standard focal length macro really effectively, and would have had a nice walkaround lens as well.

This makes sense, but what other lenses does the OP have? I already have a 50mm f/1.4 so would go with the 100mm. This would give me twice the reach of my 50 and also a macro lens.

audiobomber · 09-23-2008, 04:36 AM

I photographed a coin with a DA 35mm macro lens. I moved closer and closer until I had the magnification I wanted. It was an impressive shot, but the lens was actually resting on the coin. I intend to go for the 100mm macro, because I like to shoot insects.

Russell-Evans · 09-23-2008, 05:45 AM

Originally posted by tubadad

This makes sense, but what other lenses does the OP have? I already have a 50mm f/1.4 so would go with the 100mm. This would give me twice the reach of my 50 and also a macro lens.

But you could just go with extension tubes for the 50mm.

Thank you
Russell

Russell-Evans · 09-23-2008, 05:49 AM

Originally posted by audiobomber

I photographed a coin with a DA 35mm macro lens. I moved closer and closer until I had the magnification I wanted. It was an impressive shot, but the lens was actually resting on the coin. I intend to go for the 100mm macro, because I like to shoot insects.

If you have a TC, you might try it with the 35mm to see if the IQ is acceptable to you.

Thank you
Russell

flyer · 09-23-2008, 06:41 AM

Originally posted by Venturi

I've got the Tamron 90mm and absolutely love it as an all around macro lens. But if you're going to get serious about shooting macro there's more to consider than merely how close you are from the subject.

DOF plays a huge part in macro photography. For example at f/16 and 6 inches from subject:

50mm yields a DOF of 0.16 inches
100mm yields a DOF of 0.02 inches

So the subject matter and light can drive your focal length requirements quite a bit. Flash and/or ND filters can even things out but they are not always available or feasible for the shot.

You are right about depth of field and distance, BUT to have the same object at the same size with a 35mm lens or a 100mm lens, the depth of field will be the same because you are going to be farther away from the subject with the longer lens, so the depth of field shouldn't be part of the equation when selecting a macro lens. The subject you intend to photograph is the most important criteria.

Jewelltrail · 09-23-2008, 06:52 AM

I vote for the 100mm, mainly because it gives you working distance, which gives you more options in your Macro shooting. But you will have lots of fun no matter which one you choose.

Serpiente · 09-23-2008, 07:11 AM

depends what you want.. for animals you need at least 100mm.. for flowers lower is also good, because you can get close.. I wish there was a 150mm for Pentax

flyer · 09-23-2008, 08:07 AM

I wish I could put my hands on an old PENTAX 200 macro.

augustmoon · 09-23-2008, 11:23 AM

funny how many answers given so far, when the original poster was so completely vague about what they wanted to shoot with it, or how they wanted to use it or what other lenses they had...

Originally posted by innershell

If it will fly away and get scared easily, get the 100mm. Otherwise, any of those lenses will work. I got my 90mm simply because bugs don't like a big piece of glass near their face.

I don't see where the OP mentioned bugs.

Macro could mean a wide variety of subject matter (bugs, flowers, coins, product detail, abstract, etc..) and shooting distances, styles (hand-held, or tripod) methods (fleeting moment or carefully staged studio shot) , type of background desired, how much DOF, size of subject and level of magnification, etc...

So, until the OP responds with this info, it could be anything from the da35 to the da300 or anything in between or shorter or longer with tubes, or bellows, or reverse-mount rings.

09-22-2008, 08:59 PM	#1
tscip22 Senior Member Join Date: Sep 2007 Location: Minnesota Posts: 157	Which Pentax focal length for Macro? I am wavering between a 35, 50 or 100 mm focal length Pentax DA macro lens. Which one do you use, and why? I currently use a K10

09-22-2008, 11:00 PM	#5
Venturi Veteran Member Join Date: Mar 2008 Location: Tulsa, OK Photos: Gallery Posts: 2,636	I've got the Tamron 90mm and absolutely love it as an all around macro lens. But if you're going to get serious about shooting macro there's more to consider than merely how close you are from the subject. DOF plays a huge part in macro photography. For example at f/16 and 6 inches from subject: 50mm yields a DOF of 0.16 inches 100mm yields a DOF of 0.02 inches So the subject matter and light can drive your focal length requirements quite a bit. Flash and/or ND filters can even things out but they are not always available or feasible for the shot. Last edited by Venturi; 09-22-2008 at 11:09 PM. Reason: crossed numbers. d'oh

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09-22-2008, 09:22 PM	#2
Ole Administrator Join Date: Sep 2006 Location: Copenhagen, Denmark Photos: Gallery \| Albums Posts: 4,409	100mm - you need to have some distance from the lens to the subject!

09-22-2008, 10:38 PM	#3
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,987	Up until a month ago, I would have agreed 100% with Ole. I just returned from the annual hauling of the trailer. Something I noticed with my flora pictures was that I could have used a standard focal length macro really effectively, and would have had a nice walkaround lens as well. However, I did shoot some really wonderful macros of some of the various mushrooms that were erupting all over the place, and found for this that the 100mm focal length was still the best. So now I only agree with Ole 84.693%

09-22-2008, 10:48 PM	#4
innershell Veteran Member Join Date: Sep 2007 Location: Edmonton, AB, Canada Posts: 408	If it will fly away and get scared easily, get the 100mm. Otherwise, any of those lenses will work. I got my 90mm simply because bugs don't like a big piece of glass near their face.

09-22-2008, 11:09 PM	#6
Venturi Veteran Member Join Date: Mar 2008 Location: Tulsa, OK Photos: Gallery Posts: 2,636	Corrected my numbers above. did calculations on inches but had feet in my head.

09-23-2008, 04:35 AM	#7
tubadad Inactive Account Join Date: Nov 2007 Location: Scarborough, ON, Canada Posts: 30	Originally posted by Wheatfield Something I noticed with my flora pictures was that I could have used a standard focal length macro really effectively, and would have had a nice walkaround lens as well. This makes sense, but what other lenses does the OP have? I already have a 50mm f/1.4 so would go with the 100mm. This would give me twice the reach of my 50 and also a macro lens.

09-23-2008, 04:36 AM	#8
audiobomber Veteran Member Join Date: May 2008 Location: Sudbury, Ontario Photos: Albums Posts: 6,806	I photographed a coin with a DA 35mm macro lens. I moved closer and closer until I had the magnification I wanted. It was an impressive shot, but the lens was actually resting on the coin. I intend to go for the 100mm macro, because I like to shoot insects.

09-23-2008, 05:45 AM	#9
Russell-Evans Veteran Member Join Date: Nov 2007 Posts: 1,553	Originally posted by tubadad This makes sense, but what other lenses does the OP have? I already have a 50mm f/1.4 so would go with the 100mm. This would give me twice the reach of my 50 and also a macro lens. But you could just go with extension tubes for the 50mm. Thank you Russell

09-23-2008, 05:49 AM	#10
Russell-Evans Veteran Member Join Date: Nov 2007 Posts: 1,553	Originally posted by audiobomber I photographed a coin with a DA 35mm macro lens. I moved closer and closer until I had the magnification I wanted. It was an impressive shot, but the lens was actually resting on the coin. I intend to go for the 100mm macro, because I like to shoot insects. If you have a TC, you might try it with the 35mm to see if the IQ is acceptable to you. Thank you Russell

09-23-2008, 06:41 AM	#11
flyer Veteran Member Join Date: Jan 2008 Location: Ste-Anne des Plaines, Qc., Canada Posts: 2,013	Originally posted by Venturi I've got the Tamron 90mm and absolutely love it as an all around macro lens. But if you're going to get serious about shooting macro there's more to consider than merely how close you are from the subject. DOF plays a huge part in macro photography. For example at f/16 and 6 inches from subject: 50mm yields a DOF of 0.16 inches 100mm yields a DOF of 0.02 inches So the subject matter and light can drive your focal length requirements quite a bit. Flash and/or ND filters can even things out but they are not always available or feasible for the shot. You are right about depth of field and distance, BUT to have the same object at the same size with a 35mm lens or a 100mm lens, the depth of field will be the same because you are going to be farther away from the subject with the longer lens, so the depth of field shouldn't be part of the equation when selecting a macro lens. The subject you intend to photograph is the most important criteria.

09-23-2008, 06:52 AM	#12
Jewelltrail Veteran Member Join Date: May 2008 Location: Rhode Island Photos: Albums Posts: 4,180	I vote for the 100mm, mainly because it gives you working distance, which gives you more options in your Macro shooting. But you will have lots of fun no matter which one you choose.

09-23-2008, 07:11 AM	#13
Serpiente Senior Member Join Date: Jul 2008 Posts: 154	depends what you want.. for animals you need at least 100mm.. for flowers lower is also good, because you can get close.. I wish there was a 150mm for Pentax

09-23-2008, 08:07 AM	#14
flyer Veteran Member Join Date: Jan 2008 Location: Ste-Anne des Plaines, Qc., Canada Posts: 2,013	I wish I could put my hands on an old PENTAX 200 macro.

09-23-2008, 11:23 AM	#15
augustmoon Inactive Account Join Date: Mar 2008 Location: Toronto, San Diego, Seattle Posts: 455	funny how many answers given so far, when the original poster was so completely vague about what they wanted to shoot with it, or how they wanted to use it or what other lenses they had... Originally posted by innershell If it will fly away and get scared easily, get the 100mm. Otherwise, any of those lenses will work. I got my 90mm simply because bugs don't like a big piece of glass near their face. I don't see where the OP mentioned bugs. Macro could mean a wide variety of subject matter (bugs, flowers, coins, product detail, abstract, etc..) and shooting distances, styles (hand-held, or tripod) methods (fleeting moment or carefully staged studio shot) , type of background desired, how much DOF, size of subject and level of magnification, etc... So, until the OP responds with this info, it could be anything from the da35 to the da300 or anything in between or shorter or longer with tubes, or bellows, or reverse-mount rings.