[trog100]

the detail in these is pretty much lost with the downsize..

one was taken with sigma 50mm EX true macro prime lens..

the other with a tamron 1.4 tele converter (cheap) a sigma 28-90 super cheapo zoom lens and a plus 4 close up on the end..

completely untouched except for the downsize.. jpegs from a k100d..





trog

[clarenceclose]

I think I am seeing greater DOF with the macro and more clarity on the serrated wheel. If I were looking for hairs on a bee's back it would probably be using the macro lense.

[trog100]

seem full size there really isnt a lot in the detail differences the sigma 50mm is tack sharp it cant really be beaten and at that magnification we are talikng hairs on a flies back not a bee.. a bee would pretty much fill the entire frame..

to be honest i am amazed the cheapo sigma zoom cobble-up comes anywhere near a real macro lens.. it also does it from a reasonable working distance.. of about six inches.. as opposed to an unusable in the field 1.5 inches from the 50mm lens.. its basically similar to a 130mm macro lens.. not a cheap item..

the dof comes down to how small a lense opening u can get away with.. its pretty good on both of them to be honest one is at f22 the other f32..

seem fullsize on my monitor the flint wheels are about 12 inches across.. i can see the difference.. at the posted image size all u can do is imagine the difference..

i assume u have read the exif info and know which image is which.. ???

trog

[clarenceclose]

No but it looked like the upper one was the macro and the lower one was not as sharp. Very interesting and as you said, 6" is a better working distance for macros than 1.5". So which was f22 and which f32?

[trog100]

a 100% crop.. size wise lets say a small part of a bee..



the real macro lens was f22 i think.. but one is at more of an angle than the other and it dosnt help it from a dof point of view.. one is slighty more exposed than the other which gives it an edge at small size viewing from a sharpness point of view..

trog

[philzucker]

Interesting comparison! I assume in the original post the upper one was done with the combination, the lower one with the macro lens? (Just looked at the filenames ...)

AFAIK the difference between a "true" macro lens and any other combination is not only sharpness, but also better contrast and color rendition and less lens errors.

A macro lens with it's built in tube is optimized for what it does, has (or should have) corner to corner sharpness and "flat field" view (meaning everthing is sharp in a single focal plane - important for reproducing e.g. documents). Especially standard close up lenses like you used here tend to loose sharpness noticeably at the edges, standard lenses especially in combination with tubes have problems with flat objects if used wide open. Would be interesting to see if you photograph e.g. a stamp or a part from a stamp directly from above (sensor and stamp perfectly parallel) with different f-stops and then to compare overall and corner to corner sharpness of your two setups.

Combinations like you have used here with the "cheap" alternative can magnify lens errors not noticeable in normal use. In challenging light conditions you may see CA crop up, or will have reduced contrast and not so good color rendition compared to dedicated macro lenses. One reason for that is the simple fact that with a teleconverter and a close up lens added you introduce more glass surfaces, and every single surface - coated or not - will worsen optical quality a bit - especially if there is direct light or very contrasty light to deal with.

On the other hand you can save much in the digital age through PP work. so the impact of those differences can diminish - and we never should forget that not the tool used, but the result achieved is all that counts. Here a macro I once did with a pretty cheapo setup - a Kenko 2.0 tele converter combined with a manual SMC-M 50/1.7 gave this uncropped pic:



Phil

[trog100]

theory apart for handheld live subjects the cheapo combo would be hard to beat.. the working distance enables the cameras inbuilt flash to function without the lens getting in the way.. the errors towards the outer edges of the frame dont really matter with live subject macros.. most of the image normall isnt in focus anyway.. getting enough dof is the real problem..

1/15 of a second f1.7 at iso 800 i assume mounted on a tripod on a windless early morning.. wouldnt capture a live moving subject.. the dof would be about 1/8 inch at the most.. the cobweb is a beautifully image but a 2x tele on an old pentax prime 50mm isnt going to produce a true macro..

the sigma 28-90 or 28-80.. lets say 50 dollars new.. mine cost £30 pounds.. the tamron tele.. that one cost £40 new last week.. lets say £10 for a hoya plus 4 close up.. a frame fill of say about 3/4 inch from a six inch working distance is remarkable..

it would need £600 worth of real macro lens to get even vaguely close to it..

on its own the little sigma zoom produces a 1:2 macro at about 3 to 4 inches with a frame fill of about 2 inches.. the image quality is very good.. the more expensive 50mm macro pime has superb image quality but its working distance is too close.. it needs a ringflash.. sadly there isnt one available for the pentax 100d or k10 at the moment..

the cheap tamron 1.4 tele is a little gem as well..

i am not much into post processing to be honest.. i think the dividing line between photography and graphics artistry is being oversteped.. lots of thing can be done with post proccessing.. a little too much in my oppinon.. he he

trog

ps.. i am more concerned with in the field handheld flash usage small aperture capturing of very small objects.. i agree entirely with your comments as regards the other types of macro..

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Last edited by trog100; 12-06-2006 at 07:37 AM.

[jeffkrol]

Not really , a good used manual 50mm Macro would not cost you anywhere near 600, and would have less glass, weight, better field flatness, arguably sharper (I wouldn't argue it), fewer fingerprints . As to cheap, a Vivitar Macro teleconverter and a cheap M50 f1.7 prime would be a good alternative.... $200 US tops, unless you are carried away by ebay fever. Though it's fun, stacking glass upon glass upon glass is just not errr "nice" and seems counter productive to achieving quality and simplicity.

[trog100]

i tend to think new prices as cheap.. old quality glass is a bargain.. he he

my pentax manual 50mm 1.7 cost me 15 quid.. okay it was very cheap even at ebay prices but if something similar was produced today it wouldnt be cheap.. in fact it would be ludicrously expensive..

the 1:6 or less type magnfication a normal 50mm prime gives isnt a macro.. the 2 x tele just makes it into a 100mm prime not a macro lens..

the one to grab is the old vivitar 100mm manual macro with a genuine 1:1 magnification.. the ebay priceof such things is going up thow someone paid £135 for an old pentax 50mm manual macro just few days ago on ebay.. my son and i have tried many a macro alternative.. i am currently watching an old manual 200mm so called macro.. if it dosnt rise to silly money it will become part of the macro testing collection .. he he

the word macro is tending to mean silly money on ebay at the moment.. not sill money compared to the new offerings but silly money for 25 year old glass that not long ago nobody wanted..

my problem with the silly money is the condition they are in.. its a risk.. the risk factor limits what i am prepared to pay..

my £600 price is the price a half decent 150mm 1:1 new macro lens would cost.. the 150mm is needed for the live subject working distance..

trog

[philzucker]

theory apart for handheld live subjects the cheapo combo would be hard to beat.. the working distance enables the cameras inbuilt flash to function without the lens getting in the way.. the errors towards the outer edges of the frame dont really matter with live subject macros.. most of the image normall isnt in focus anyway.. getting enough dof is the real problem..

My remarks were aimed at the general differences between dedicated macro lenses and combo setups like yours (and mine with the cobweb shot). It's true that for a lot of subjects - but definitely *not* for all! - sharpness in the middle of a lens is good enough. The working distance you mention here is just a factor that is introduced with the focal length. Compare a dedicated macro lens of one of the typical focal lengths - e.g. 50, 70, 90, 100 or 180mm - with a combo setup giving the same focal length (and do incorporate the close up lens into the equation, it changes the "real" focal length) and then compare the results ...

1/15 of a second f1.7 at iso 800 i assume mounted on a tripod on a windless early morning.. wouldnt capture a live moving subject.. the dof would be about 1/8 inch at the most.. the cobweb is a beautifully image but a 2x tele on an old pentax prime 50mm isnt going to produce a true macro.

I'm not sure what you are driving at here? The shot is an uncropped 1:1 macro shot done with a Kenko 2.0 macro tele converter (has a built in tube). We can discuss edge resolution and other lens errors produced by this setup, and of course overall sharpness compared to a 100mm macro lens - but if a 1:1 macro shot is not a true macro then what is?!

Phil

[trog100]

i really am not about the perfect picture nit picking debate.. i simply posted a couple of comparison macro pics.. in your original post u did not mention a "macro" tele converter simply a 2 x tele converter my assumption of the combination not being a true macro was quite reasonable..

here is a flat type full frame shot taken with the cheap combo.. it seems reasonably across the entire frame with no obvious problems.. its part of an english £20 pound note.. the queens eye..



the working distance was about three inches from the end of the fully extended lens.. about ten iches from the centre of the camera body.. quite workable in real life..

the combo produces about a 24mm frame fill or just under one inch.. F32 with an olympus T32 flash on the camera.. the little on-camera flash would probably have done the job.. handheld and taken pretty much the same way as say a bee on a flower..

its as much about usabilty as taking the best macro picture on the planet.. most of the live subject ones i take fail abysmally..

handheld its not going to work at f2.8.. in good light it might work at f16 or f22 with no flash..

dont get me wrong.. i expected poor results the combo isnt mine the bits belong to my son.. when the results compared favouably to the results from my 50mm macro prime it atracted my interest..

i really aint into the real macro vs the cheap cobble up debate.. this particular cobble up works.. some seem offended by the mere suggestion that "cheap" can work.. me.. i see the kings clothes for what they really are..

trog

ps.. straight from the camera jpeg.. just down sized for posting..

ps. 2.. your cobweb picture gets better the more i look at it.. especially the reflections in the larger droplets.. he he

[philzucker]

Sorry for my reaction, but I thought that one could see that those drops on a spider web couldn't be 1:6 only. And I hope you don't mean *me* with "some seem offended", because I posted my pic in support of low cost alternatives.

I stay with what I said: Dedicated macro lenses generally offer better sharpness & better contrast compared to non dedicated combos. At least that is my experience - I use the combo I took the spiderweb with, but also own a Tamron 90 macro lens. Generally means that you *can* achieve great results with a combo, even with a close up lens under certain conditions (still looking for a deluxe close up lens, a diopter, as light, portable and high quality "take with you" macro). But with any specialized optics it is usally easier to achieve consistent high quality results with it, especially under challenging conditions. YMMV of course.

That said I don't want to harp on flat field comparisons, because I think they are simply not important to you (if they were I'd advise not stopping down that much for optimum results - diffraction kicks in at f32 for one ...) Usablity is what counts for you, and your combo simply seems better for your because it allows for a better working distance compared to your 50mm dedicated macro lens. So use your combo (if your son can loan the parts for a while), make pics with it and share them! :-)

Phil

[trog100]

i havnt finished expermenting yet.. he he



a 100% crop of another flint wheel.. a 15 quid ebay komura x2 manual tele with my 50mm sigma macro lens.. never heard of komura but its a seven element nicely made looking thing and probably quite old..

at about 2 inches from the end of the lens working distance it gives an 11mm frame fill.. the old olympus T32 angled down is just high enough to light it and clear the lens end..

as regrads usabilty.. well u have to be able to take the picture before u can pixel peep it.. he he.. the very small lens opening just has to be for things with any depth..

anyways that image of your is a work of art the more i look at it the more it fascinates me.. all i am after is the ability to take casual snaps of very small things..

take care

trog

[HogRider]

The most important thing to me in a macro lens (besides sharpness, but they all are anyway) is the way how a lens renders the out of focus areas. The way a Macro shows the "bokeh" is what it is all about for me. Now if you are just using it for re-pro work, bokeh isn't important, but for bugs and flowers etc.. it can make the difference between a good and sharp macro image and a "great' macro image. Just my 2 ¢.

[trog100]

yes.. more so with flowers i think..

trog