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Canon 20mm f3.5 Macrophoto lens
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PostPosted: Tue Aug 28, 2018 1:49 pm    Post subject: Canon 20mm f3.5 Macrophoto lens Reply with quote

Couple of shots of a flower in my garden using the Canon 20mm f3.5 Macrophoto bellows lens. Mounted straight on the camera this time, as I was just trying it out. As these are with the lens mounted directly on the camera without bellows, and I think it gives a 1-2x lifesize image like that. To be honest this lens needs a tripod and additional lighting, especially at higher magnifications. These were taken at ISO2500 and 4000 and f8, and even so, I was at the limit of hand holding it. 2 pictures showing the lens on a camera as well.


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PostPosted: Tue Aug 28, 2018 4:49 pm    Post subject: Reply with quote

Very nice Jonathan! Bit used outside its specs (which calls for longer extension), but clearly shows how well this lens works even there!
Here it is on my macrolenses database: http://www.macrolenses.de/ml_detail.php?ObjektiveNr=9


PostPosted: Wed Aug 29, 2018 12:03 am    Post subject: Reply with quote

Canon also made a 35mm f/2.8 bellows macro lens. I've long wondered how these two lenses perform, and I think these are the first photos I've seen from one.

Back when I was a regular FD shooter, obtaining one of those lenses was always on my "to buy" list, but I never did get one. Nice to finally see one being put to proper use. You should really try them out on bellows, though.


PostPosted: Wed Aug 29, 2018 9:16 am    Post subject: Reply with quote

Thanks Klaus, yes outside of how it's meant to be used, but still I'm very impressed with it.

Cooltouch, definitely, I shall be trying it out either on bellows or using extension rings. These shots were really just to see if it was ok. Even like this, hand holding was virtually impossible, so I shall have to have a good think about how I will hold it and light the subject for using it on bellows/extension tubes. This one came up for auction near to me, and I made the guy an offer on it. I was amazed when I opened the box, that it looked basically unused. Apparently the guys father bought it in the 1980s for some reason and he found it when emptying his fathers house. I shall keep an eye out for the 35mm one too Smile


PostPosted: Wed Aug 29, 2018 1:27 pm    Post subject: Reply with quote

You're gonna have to use a tripod, or some other sort of stable support -- like a copy stand -- when you use that lens with a bellows. What I found to be very useful when working with high magnification, especially when outdoors, was a focusing rail. I bought one of these:

Click here to see on Ebay

It's useful because it allows for small precise movements in both the x and z directions, but not y. Can't have everything, I suppose. I mount my bellows with camera attached directly to this focusing rail, then mount the assembly to my tripod. With this employed, once I have my subject within a reasonable range of the viewfinder, I can use the focusing rail's controls to center the subject and even bring it into precise focus. Very handy for high magnification work.


PostPosted: Wed Aug 29, 2018 3:19 pm    Post subject: Reply with quote

Thanks for the link Cooltouch. I do have a Kaiser copy stand, with a fine control on the vertical, so will give that a go first, however I probably will end up getting a dedicated rail for the fine movements.

As an aside, the 35mm version, there are a few on eBay at the moment but for considerably more than I paid for the 20mm version. I think the 35mm one will have to wait for now....


PostPosted: Thu Aug 30, 2018 11:59 am    Post subject: Reply with quote

While it wasn't raining I tried a couple of shots of a sunflower in UV. These were done with a UV converted Canon Eos 7D, and again without extension tubes. Hazy sunlight, ISO640, f11 and 30 seconds exposure. Mirror lockup and a 2s delay on the shutter. White balanced on a PTFE tile. Camera and flower balanced on the wooden decking in the back garden, and yes I need to get a better support sorted out. The first image is of 2 of the petals, and the second image part of the centre of the flower with the petals in the background.


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PostPosted: Thu Aug 30, 2018 12:11 pm    Post subject: Reply with quote

I have a Olympus Zuiko 20mm F3.5 which is very similar to this Canon. The link to the thread about my lens:

http://forum.mflenses.com/viewtopic.php?t=68105


PostPosted: Thu Aug 30, 2018 3:47 pm    Post subject: Reply with quote

Wow, nice detail. Only thing is, for the subject, even f/11 is a bit lacking as far as depth of field goes. Might be time to try f/16 or higher. If you can do a 30 second exposure with no movement of the subject, you should be able to do longer with little problem.


PostPosted: Sat Apr 11, 2020 11:00 am    Post subject: Reply with quote

JMC wrote:
While it wasn't raining I tried a couple of shots of a sunflower in UV. These were done with a UV converted Canon Eos 7D, and again without extension tubes. Hazy sunlight, ISO640, f11 and 30 seconds exposure. Mirror lockup and a 2s delay on the shutter. White balanced on a PTFE tile. Camera and flower balanced on the wooden decking in the back garden, and yes I need to get a better support sorted out. The first image is of 2 of the petals, and the second image part of the centre of the flower with the petals in the background.


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Missed this one, nicely done Jonathan! Never tried UV with those Canon dedicated macro lenses!!


PostPosted: Sat Apr 11, 2020 3:53 pm    Post subject: Reply with quote

There might be something of interest here:

https://www.photomacrography.net/forum/viewtopic.php?t=38216

https://www.photomacrography.net/forum/viewtopic.php?t=36249

https://www.photomacrography.net/forum/viewtopic.php?t=12506


PostPosted: Sat Apr 11, 2020 8:02 pm    Post subject: Reply with quote

Thanks Klaus. I'd forgotten about this - I must run the Canon 20mm through my lens transmission setup and see how far into the UV it goes.

E6filmuser, cool links. The stacking that people do for these macro images amazes me. I don't have the patience for it at the moment, but later perhaps.


PostPosted: Mon Aug 16, 2021 9:31 pm    Post subject: Reply with quote

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Last edited by Blazer0ne on Tue Feb 22, 2022 4:09 pm; edited 1 time in total


PostPosted: Thu Oct 14, 2021 12:48 pm    Post subject: Reply with quote

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Last edited by Blazer0ne on Tue Feb 22, 2022 4:09 pm; edited 1 time in total


PostPosted: Thu Oct 14, 2021 10:07 pm    Post subject: Reply with quote

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Last edited by Blazer0ne on Tue Feb 22, 2022 4:09 pm; edited 1 time in total


PostPosted: Sat Oct 16, 2021 12:37 pm    Post subject: Reply with quote

Blazer0ne wrote:

.......... I ran into the end of the focus helical.



Do you have a picture with the whole macro rig?


PostPosted: Sat Oct 16, 2021 1:49 pm    Post subject: Reply with quote

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Last edited by Blazer0ne on Tue Feb 22, 2022 4:09 pm; edited 1 time in total


PostPosted: Sat Oct 16, 2021 5:09 pm    Post subject: Reply with quote

That helicoid tube is not good when working at high magnifications.
Put the lens on a dedicated macro rail: Contax, Minolta, Pentax etc.
Hand held is out of the question.


PostPosted: Sun Oct 17, 2021 1:24 pm    Post subject: Reply with quote

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Last edited by Blazer0ne on Tue Feb 22, 2022 5:39 pm; edited 1 time in total


PostPosted: Mon Oct 18, 2021 6:38 pm    Post subject: Reply with quote

I've not seen the drop in filter adapter unit. Explain please.


PostPosted: Mon Oct 18, 2021 8:58 pm    Post subject: Reply with quote

Blazer0ne wrote:
Of course I use a tripod. I can really dial it in with a video head.

For the macro rail are you referring to something like the Nikon Pb-4 or Pb-5 bellows?


PB-4 would be my choice due to swing & shift movements.


PostPosted: Wed Oct 20, 2021 8:49 pm    Post subject: Reply with quote

Blazer0ne wrote:
I used focus stacking so it was nothing more than a standard M42 macro helical.


Interesting drop-in rear filter tube - did you 3d print it entirely or did you combine existing hardware?

/Edit/ I just saw your post in the adapter subforum:
http://forum.mflenses.com/mounting-2-filter-drawer-behind-lens-t82992.html


BTW, most people report better stacking results when they vary the distance between camera and subject, either by moving the camera or the subject. Varying the amount of extension can introduce problems for the stacking software.


PostPosted: Thu Oct 21, 2021 4:44 am    Post subject: Reply with quote

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PostPosted: Sat Dec 17, 2022 1:46 pm    Post subject: Reply with quote

A few years ago I got both the Canon Macro Stage as well as the Canon Auto Bellows for the FD system. Some months later I had the chance to buy a Canon Macro Photo Lens 20mm 1:3.5 with the dedicated Canon Macro Photo Lens Adapter. THese four parts (or a similar other bellows) are necesssary to take good images with the 3.5/20mm Macro lens.

For years the setup was laying around, litteraly collecting dust. Yesterday - on the attic, while looking for something else, I found a small piece of rock I had found as a teen in the Val Nalps (Swiss Alps). Apart from some rutile crystals (titanium dioxide) it had also a tiny (< 0.5mm) yellow crystal from a rare elements mineral (maybe monazite). So finally I took out the Canon 3.5/20mm Macro lens ... and here it is:





Monazite used to be the main mineral for getting rare earth elements, especially lanthanum (which is used in nearly every high performance lens). Later on (from the 1970s) monazite was replaced by bastnäsite, since monazite does contain (radioactive) thorium which is rather difficult to separate.

S


PostPosted: Sat Dec 17, 2022 3:39 pm    Post subject: Reply with quote

Ah yeah, scale is about 10:1, thus still in the recommended range (4:1 ... 10:1). At this level of magnification, the effective aperture is far smaller than the nominal aperture (eg f3.5 wide open). Therefore diffraction kicks in violently when stopping down the lens. The two images above were taken af f8 (nominally). The distance from the sensor to the lens is about 20 cm or tenfold the focal length. Thus I would estimate the effective aperture to be around f32 wide open and around f80 in the images shown above. Of course this results in strong diffraction effects, and in an accordingly reduced detail resolution. A 100% crop from the center 24 MP FF sensor looks quite mediocre:



This, of course, isn't a fault of the lens.

Other than that, at an effective aperture of around f100, any dust on the sensor is a huge issue. Even small particles with a diameter of maybe 20 micrometer can create spots on image (with a diffraction induced onion / donut pattern).

S