Are you aware of Robert O*Toole's own sites? www.closeuphotography.com/
Good reviews and tests of macro lenses.
July 3, 2023
50
-
-
Thanks! Yes, of course - it‘s one of my most-trusted sources. Also had a lot of interesting conversations with him - he‘s very helpful and knowledgeable in a range of topics! I appreciate people like him with a real curiosity who continually tread new ground.
-
I started that forum with Tom in 2002, brought on Mike and early this year handed it over to Rik. Not many forums last that long 😀
-
Wow - excellent work, then! A vast amount of experience and knowledge in that place.
@JimKasson I‘m looking forward to your macro experiments - it‘s a really interesting magnification range you‘re about to try. Hope everything works out as planned.
-
Thats really cool mate. just now ive picked up a used Olympus 10x objective with 10.5mm working distance for $50 bucks couldnt resist. my current 10x is only 5.5mm so 10mm is going to be a game changer. i was considering a new one for $700. $50 is fish and chips 😁
-
Hi,
I am curious to see how this works out.
I have done a lot with microscopes. Usually binocular with a way to switch one path to a tube rather than an eyepiece. Then there is a camera on the tube. I've had many Nikon scopes at places I have worked. My personal one is a Leica which sports a Canon mount. That one has had a Kodak DCS 520c on it for decades now. All of 2 MP and APS-C.
I've not tried greater than 1:1 with a macro lens directly. I do use the macro lenses on a Kodak 760c on a copy stand. But the entire idea is to have 1:1 or less. I refer to it as my Wide Field Macroscope. In use, the 760c 6 MP APS-H gives me a shot of damage with the undamaged area around it. Then we zoom in, so to speak, by sticking the board under the microscope.
And the microscope has polarized light with a polarizer filter so I can vary the field to best show the damage. This is a step beyond Bright Field, Dark Field some scopes offer as the polarization is continuously variable.
I'm not sure any of my experience can be of any help here, though.
Stan
-
I've thought some more about this and I see an issue that I'll have to deal with should I pursue your-- quite inventive -- idea. The LoCA occurs because the lens has different focal lengths for different wavelengths. Therefore, I'll have to scale two of the color planes before I generate the color image.
-
At 10:1, 4.4x3.3 mm. The image circle diameter at that magnification is 14.5 mm.
-
No need. The image circle is 14.5 mm in diameter at 10:1.
-
I don't see how that applies to this lens.
-
I don't think I'll be making images of insects. Others, including you, have done that quite well. I'm expecting a FoV of 3.3 by 4.4 mm. We'll see what the working distance is. I don't think it will be as short as 6mm.
-
But...
Isn't that just what the CA correction is doing in photo editing programs? Scaling color channels to cover the same area?
Yes, that's correcting LaCA and LoCA makes those color halos. But if you use LEDs with very narrow band, no overlapping, is there so much to correct or is the correction too hard? Maybe it's hard to get color balance right if color channels are not overlapping? -
I'm not saying that it's impossible, just something I'll have to account for and correct. Using three narrowband sources will allow production of a color image, but not one with anywhere near accurate colors.
-
9 should work ;)
-
Not only scale - it is possible that other wavelengths create astigmatic images, their focus planes are not planes at all and whatever other distortions may occur. This 'multispectral imaging' is just idea for experiments.
If you have different colors of same part of object focused in different images, then IMO you can't apply successful CA correction, even focus stacking seems not easy.
Correct (unless source object has no peaks in reflection spectra - in this case relatively good colors may be achieved).
I didn't explain in my original comment that I thought about creating 'false color images' (this was implicitly referenced by 'astrophotography'). If your goal is to get best resolution, then you probably have to sacrifice some color information.Anyway, we are eagerly waiting for your results [of inverse photolitography], first in monochrome of course :)
-
Beg to differ ;)
It's easier to try in colour first.
A similar lens was quite usable in 400 .. 700 nm range. -
with all our great programs we have today, wouldnt be easier to just stitch together 2 FF stacks . your going to be shooting 2x as many images to get the same overlap and DOF compared to FF anyway and its so much easier and way cheaper to buy FF atachments. i wish i had a link to a guy 5 years ago that shot microchips for a living. and shot 3d revolving images sometimes taking up to 40,000 images. his set was amazing a whole 5x5 meter room was needed to setup the gear. he used to visit DPR quite regulary. from memory he shot nikon d850.
-
I've got the GFX 100S already, and an Actus, an Ultima II, and a TC-1. So that's a sunk cost. To get the same DOF by picture height as FF, I need to shoot 33/24 = 1.375 times as many images, not twice as many.
