Lighting for macro photography of fern gametophytes

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

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jsp
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Post by jsp »

Thanks JohnyM, I think that's what I'm seeing.

jsp
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Post by jsp »

I just listed my MP-E on ebay, so I can switch to the x5 Mitutoyo. Fingers crossed.

ChrisR
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Post by ChrisR »

The 10x on 100mm is a very sharp combination, but it won't cover your frame.

You mentioned putting a 10x objective on a 50mm "tube" lens. That will give you a circular image.
The 5x is designed to give a 24mm diameter image on a 200mm tube lens.
That would become 6mm diameter on your sensor with a 50mm tube lens. We know they do a little better, but even so.

I wouldn't part with the MP-E before trying a Mitutoyo - pester the person with "a drawer full" !
Beatsy's test didn't show the corner detail, as far as I remember. This one, once you find it, does show corner fall off for the Mitty 5x:
http://www.macrosmuymacros.com/index.ph ... me-test-5x


NB if you add a comment on your ebay listing that the lens is advertised elsewhere, you have a degree of freedom. If ebay think you are selling "behind their back" they can take the commission from as though you had sold it on ebay, if you withdraw it. (Recent rule change).
Chris R

jsp
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Post by jsp »

Hi Chris,

Thanks, that's good to know about the ebay rule. I didn't know that. I have stopped the sale on ebay and here. It's really tricky to know what to do as the images I'm getting on the MP-E are not great. They Mity ones are much better. It seems silly to keep it. I have emailed the guy with the drawer of lenses and I will try emailing again. Maybe he will reply this time. :-)

I didn't realise the circle would be smaller with a shorter lens. I was reading a book on 35mm photography last night, but I still struggle to get to grips with the implications of the different lengths and the ways they combine with the objective.

I'll try that guy again and see if I get anywhere.

Thanks!

jsp
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Post by jsp »

My helpful new friend has asked if I can borrow this lens. Fingers crossed.

Image

ChrisR
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Post by ChrisR »

Prudent move, I think.
I don't know if ebay have actually implemented their new rule and they wouldn't do it lightly I'm sure. Nasty though.

Bothering me, is that if you look at say Beatsy's comparison of the whole frame, both look OK. You have to go right in to see the difference. It makes it looks like something else is being difficult, in your test. Your subject is quite shiny - even more diffusion may help. (Though I'd have thought it should show similarly at similar effective aperture).

Beatsy's comment:
Bear in mind this picture does not tell the whole story by a long shot. The MP-E 65 does 1x-5x with continuous zoom across the range, has little or no corner vignetting, has adjustable aperture (f/2.8 - f/16), and image quality at the edges is way better than a mitty on tube lens shorter than 200mm. ... .. Having said that - if you want one specific magnification like this, and resolution is most important, then yes, the mitty is probably for you.
The nub of the problem is that an image width around 7mm is a crossover between mainstream macro lenses and microscope objectives. Resolution+coverage wise, there's a bit of a tight point. (Using a smaller sensor shifts the magnification you need, but the pixels are smaller so it's something of "a wash".)

How big a print do you need? There's no actual limit, you can always stitch a load of images (ugh :shock: ). You have to stop somewhere!

Again Charlie's http://www.photomacrography.net/forum/v ... =9757#9757

Beatsy's http://photomacrography.net/forum/viewt ... e037b84f28
Chris R

jsp
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Post by jsp »

Hi,

I'm aiming for A3. Hopefully I might get a go of this borrowed Mity and then I'll have a better idea.

I know what you mean about there maybe being some other factor though. Adding those two UV filters to my current setup was transformative, which is now making me very suspicious of details. :-)

Thanks!

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Post by ChrisR »

I've been checking. If you get an appropriate tube lens, the 10x will cover your frame, down to about 150mm "tube", giving 7.5x. A 135mm lens will vignette a little. The edge quality will be going off, but you can probably crop the worst off in many cases.

As you'd be using NA 0.28 still, it would resolve more detail than a 5x NA 0.14.
Chris R

jsp
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Post by jsp »

Interesting! I might wait and see if get a go of this Mity 5x. Useful to have options though.

jsp
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Post by jsp »

I tried fixing the 2x Canon teleconverter on between the camera body and the 200mm prime, using a 12mm Canon extension tube in between to stop the clash between lens bits inside. This is what the stack looks like with that combination:


Image

jsp
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Post by jsp »

This is back to just the 10x. Sometimes it works well and sometimes it doesn't. With this one I had the lights on either side but one slightly from the front and one from slightly behind, still with the polystyrene cup over.

Image

Image

Then cropped:

Image

jsp
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Post by jsp »

Hello!

I've just been given a £4000 grant to buy the x20, x5 and x2 Mitutoyo objectives so I can photograph the bigger and smaller fern gametophytes. Does that sound like a good plan to buy those sizes? My plants go from a few cells tall to about 1cm tall. I will order them straight away if you think it is sensible as I have 6 months to do the work and the ordering takes a long time.

Thanks!

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Post by enricosavazzi »

jsp wrote:Hello!

I've just been given a £4000 grant to buy the x20, x5 and x2 Mitutoyo objectives so I can photograph the bigger and smaller fern gametophytes. Does that sound like a good plan to buy those sizes? My plants go from a few cells tall to about 1cm tall. I will order them straight away if you think it is sensible as I have 6 months to do the work and the ordering takes a long time.

Thanks!
The Mitutoyo M Plan Apo 2x makes sense mainly if you need to use it on the same microscope (or photomacrography stand) as the other Mitutoyo objectives. Doing this does make things simpler, especially changing magnification without moving the subject specimen to another setup. With the Mitutoyo 2x, however, you are essentially forced to use focus stacking, while a finite lens with variable aperture, at least with some subjects, may have enough DOF to allow much faster and simpler single-exposure imaging.

In conclusion, if you can use a different setup for the 1x to roughly 3x magnification, there are other solutions (finite photomacrographic lenses in the 1x-3x range with adjustable apertures) that are cheaper than the Mitutoyo and about as good image-wise, and more versatile. The setup differs from the Mitutoyo mainly in that a tube lens is not used, and magnification can be changed within a significant interval by varying the lens-to-sensor distance.

The Mitutoyo 5x is a closer call. It is not quite as good as the 10x, but close enough, and an alternative solution at 5x is more difficult to find (and most likely would involve focus stacking in any case).

The Mitutoyo 10x and 20x are very likely the best at these magnifications.
--ES

ChrisR
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Post by ChrisR »

I'd missed your latest pictures - things are looking good :)

Do you still have your MP-E 65?

I'd have to scour about old files for an image, but the Mitutoyo 2x doesn't cover as well as the rest. You get some CAs showing, which largely can be removed in post processing, though that's a pain if it's special workflow. It is a big advantage NOT to have to change "rig" to use a different objective, but would it cope anyway with your widest possible field?

I hope someone has harder info handy for full frame, Mitty 2x.
Chris R

jsp
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Post by jsp »

Hi Chris,

I do still have the MP-E but the photos aren't anywhere near as good as with the Mity 10x.

I thought maybe the lower magnification Mity lenses would be better.

This is an MP-E image:

Image


and these are a slices from another one:

Image

Image

My aim here is to get the best optics I can to cover from a few cells height up to 1cm tall, and I've currently got the MP-E and the Mity 10x, and £4000 budget. It would be great to know people's views on how best to do it.

In return for the money I committed to write a training course for secondary school kids and undergraduates to teach them focus stacking - essentially to teach them everything that you've taught me. I'm really looking forward to doing that as I've enjoyed learning it so much myself. It will be really good to have a chance to explain it to others. :-)

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