MPE focus tests.

[BasAndrews]

I am away on a course, so won't be able to do more tests until next week. I will catch up and test the same subjects at wider aprtures on my return.

Thanks again for your help everyone.

[ZoneV]

I am reading and looking at your test pictures with interest.
Are these ball-pen pictures maximum resolution you get? Did you made it with flash?

[BasAndrews]

These were shot with full flash and then an area of 1024x 768 was cut from the image to show how it looks at full size.

[ZoneV]

Thank you very much!
First I was shocked about the low resolution. But then I made a not perfect test with my lens - and it doesn´t looks better. Seem to have color problems. It is not a Canon MP-E, but a old lens without name or focal length on it, and without iris.

[Snowyman]

Picking up on a few tips from this thread, it would seem there is agreement that there is a trade off between big aperture sharpness and small apertures DOF. Clearly there is a lot of merit in having a stunningly sharp macro image but a sharp macro image is not the be all and end all. An interesting captivating image can be blurry and obscure.

It doesn't make any sense to me to scare people into not using F/13,14,16 because of the risks of diffraction occurring. I have been advised not to use F13 countless times and am still frightened to use F/16 - for fear not of creating an inferior image - for fear of creating a good image that gets panned for being slightly blurry and being told I shouldn't have used F/16. It's a trade off, there should be free trade.

Just to be absolutely clear Bas the images in Macro thread "Trying out the MP-E again Pt1" are not suffering from diffraction or if they are it is the least of their problems.

Sorry if this sounds like a rant, I've got some baggage associated with diffraction.

3x Mag at F/13

IMG_2639 by snomanda, on Flickr

[BasAndrews]

Snowy, your shots have been amongst the shots that made me assume I could get some quality at F/11 and 2 or 3x mag.

The annoying thing is it may still be me (and probably is), but I need to know.

[Snowyman]

Originally Posted by BasAndrews

The annoying thing is it may still be me (and probably is), but I need to know.

You need to describe to me/us in detail your focusing technique/s, even down to what sort of things you are thinking and experiencing in your head. Are you like me struggling to discern detail in certain light conditions and above 2x mag... Are smaller critters with smooth bodies catching you out... Do you frequently use the modelling light?... does it help? Have you tried bracketing? (taking three consecutive shots whilst moving toward the subject). Have you recalibrated your diopter? Does your eyesight vary depending on the amount of sleep you get?

Because I have all sorts of problems with my eyesight from working far too long with my computer my vision varies quite a lot day to day, hour to hour. So I have been working very hard with various techniques for achieving a degree of focus. If I restricted myself to F/8 as one person suggested I should, I would have a gallery with 3 images in it!

[Martin G.]

Snowy,

I do not think anyone is trying to scare people into using smaller apertures, but it was my impression that Bas was unhappy with the sharpness of his MPE, so it is normal that I (we?) suggest to open wider at higher magnification, in Bas's case. The suggestion is to improve sharpness only (which he is unhappy with), obviously not the shot itself. Like you mentioned, it is possible to have nice images at narrower apertures, I think Toby here does not hesitate to go smaller when he thinks it is necessary. There are a lot more important things to make a good shot than sharpness.

But before going wider, I think one needs to be able to nail everything all the time, at 1:1 and at narrow apertures, than move into more technical difficulties. One cannot start stacking images if he cannot achieve the focus where exactly he wants it consistently. So shooting wider is useless if you cannot overcome the small DOF that comes with it.

I think in the case of Bas, like you mentioned, we need to know more about the technique. I have a feeling, no offence to you Bas, that most of it is "user's" error, not the MPE.

I may have asked that to you already and I am sorry if I am repeating myself, but do you use liveview? For me, that is what makes it possible. My eyes are not good enough for the viewfinder at higner mags. Liveview is the key.

Bas, I would be interested to see shots at 1:1 just with the Tamron (no extension tubes), maybe you can post some here, or link to some you have already posted. That would already be a start. Before analysing the MPE that is a tricky lens to use, might be interesting to see what are your results with a normal macro.

Martin

[BasAndrews]

Martin,

here is a shot of a backswimmer before I got the extension tubes.

EOS 550D2562 by BasAndrews, on Flickr
and a flower shot

EOS 550D2560 by BasAndrews, on Flickr

both Tamron, F/11, 1/200th.

[BasAndrews]

All, thanks for your input, It does seem that I am at fault with the focus issue. I have a few shots even at F/14 and 3x which show the lens can give decent results.

How the previous tests gave such soft results I don't know, but for now I just need to work on taking pictures well (sounds easy if you say it quick enough!)


Again thanks to all who took the time to help, very much appreciated.