Olympus High Resolution Mode test w/60mm macro

[CarlosHermosilla]

It is also an advantage to fill the viewfinder with the subject because the focus is better appreciated (Micro 43) than to see a smaller subject in the viewfinder if we later have to crop the image (FF). I use FF, APSC and Micro 43 depending on the subject but in recent years I use the Micro 43 equipment a lot more, especially in the field. For high magnification shots I use a 200mm f 2.8 Panaleica and Mitu tube lens with an adapter, the focus bracketing capacity makes work very comfortable but above all it is very good that at Panasonic I can focus in manual mode for example in the air, before reaching the closest area of ​​the subject and the system does the focus stacking without problem; In Nikon, focus bracketing is only done in AF mode and that makes it difficult to focus accurately when the elements are very fine and poorly contrasted. Focus bracketing with manual focus is much more convenient. All the best.

[CarlosHermosilla]

One thing I don't understand is why Panasonic and Olympus don't allow you to combine high resolution mode with focus bracketing mode, that would be ideal.

Thanks

Carlos

[Lou Jost]

Carlos, I very much agree with both your posts. MFT is also my choice for most field work, and the focus bracketing is extremely easy. And it seems so stupid or lazy for Oly and Panasonic not to allow hi res focus bracketing.

However, I disagree with your choice of tube lenses. My choice of tube lens is the 45mm-175mm zoom, much cheaper than the Panasonic 200mm, and the focal length is much better suited to the MFT sensor; using more of the microscope objective's image circle and getting higher resolution on the sensor than either of the 200mm tube lenses you use. An even shorter lens would be better (for a given objective, the best tube lens for MFT is about half the focal length of the best tube lens for that objective on FF) but the other MFT lenses I have tried do not have along enough focus throw to make good focus stacks with objectives.

[CarlosHermosilla]

Lou, thanks, I can't say anything because I don't have that 45mm-175mm zoom. I'm going to make a table of magnifications and working distances for the equipment I use. For now I can say that the field covered by the Panaleica 200 mm + Mitutoyo 5x is 3.7 mm which is very useful for small subjects, the working distance is 36 mm. I am interested in knowing the field covered by the framing and the working distance of the 45mm-175mm zoom. Thank you.

Carlos

[Lou Jost]

Carlos, the image scales directly in proportion to the tube lens focal length, so whatever its field of view is on FF with a 200mm lens, you will get that same FOV on MFT sensor with a tube lens of 100mm (allowing for some variation in quality of tube lens, and the slight difference in aspect ratio between FF and MFT sensors). If the edges are soft on FF with a 200mm tube lens, then they will be soft on MFT with a 100mm tube lens. If you are happy with the objective using a 200mm tube lens on APS, then you would be just as happy with the objective on a 135mm lens on MFT.

The important thing to realize is that there is nothing special about a 200mm tube lens, except that it gives the nominal magnification for a Mitu or Nikon objective. It is just a scale issue.

Recently this issue came up on another thread, see the last page:
http://www.photomacrography.net/forum/v ... 3&start=45

Having said that, the Panasonic 200mm lens seems like a wonderful one, maybe the very best of all MFT lenses, since in some tests it is essentially diffraction-limited wide open.

[CarlosHermosilla]

In my case, using a 200mm isn't exactly a choice, it's the only one that worked as a tube lens out of the MFT lenses I have. And I'm happy with the result. If I buy a 45-175mm it would be solely for use as a tube lens as I will not be using that lens for any other type of photography. But I appreciate the advice and information, if I get a copy I'll test it and I'm interested, yes.

Thanks

Carlos

[Lou Jost]

That makes sense....