Macro Filters vs Extension Tubes

[cgw]

With respect, I'd look for any dedicated short (50-60mm) macro lens in Canon mount and skip the diopters and tubes, especially if dslr scanning is your objective. The difference in image quality isn't subtle.

 

[petrochemist]

77D doesn't have focus peaking in the turn-focus-area-red sort of thing. Besides, the focus ring might be inaccessible depending on lens choice and final design of the assembly, autofocus might be necessary.

AF is never necessary, it's a helpful extra in many situations but macro is not usually one of them - It can be used to fine tune focus however it often doesn't pick the best point to focus on, so unless working at low magnifications (technically close-up rather than macro) or shooting a flat subject, it's near useless.
Once fitted to tubes you often have to change the camera subject distance to make focus possible, the focusing movement available to the lens is often tiny compared to the extension tube length.
With many modern lenses the camera needs to communicate with the lens to change aperture, this is where the 'AF tubes' come into their own.

 

[480sparky]

Spam reported

 

[TWX]

Tubes arrived today. They're definitely cheap, and paired with one lens I get recurring camera errors that require pulling the battery to restore function (even with the tube connected) but for my purposes this won't be a big deal.

I ended up stacking all three tubes and using my 18-135mm lens at 135mm. I got basically full coverage this way, with further modification to my mozzarella imaging rig.

Long story short, I took that mozzarella bottle that I'd already cut the bottom off of and I cut the threaded top end off too. With various experimenting I realized that it was only just smaller than the 67mm-ish end on the 18-135, and with a UV filter on the lens I could slip it over that filter and it would hang on with pressure. This in turn meant I didn't have blocked or wierdly behaving focus or zoom rings, so I was able to manual focus the lens.

This is what I ultimately built:

This was the whole setup:

And this is the kind of results I got:

Those were only scaled down from 6000x4000 to 3000x2000 for the forum.

I wonder who this guy was, and which of these slides he took versus whomever took this picture took:

 

[Original katomi]

I noticed that you have a bit of colour cast and CA but I am sure software can remove that.
Nice retro of the slides

 

[JBPhotog]

Any reason you are not using a speedlight as your light source? It is a known quality in the visible light spectrum and balancing your images will be far more accurate.

Flashlights I presume are LED which are very suspect in their CRI. Older tungsten flashlights are going to be inconsistent in their tungsten balance too, CT ages with bulb life.

 

[TWX]

Any reason you are not using a speedlight as your light source? It is a known quality in the visible light spectrum and balancing your images will be far more accurate.

Flashlights I presume are LED which are very suspect in their CRI. Older tungsten flashlights are going to be inconsistent in their tungsten balance too, CT ages with bulb life.

I don't have any sort of speedlight or other camera-based artificial light source.

I noticed that you have a bit of colour cast and CA but I am sure software can remove that.
Nice retro of the slides

Thanks. I'll have to play around with them a bit. I realize in hindsight that I probably should close-down the aperture more (f/5.6 in these) to help with CA. They've come out at least useful, even if they're not perfect. The narrower aperture might also help a bit for focus since the depth of field will increase.

 

[Derrel]

You might be able to use the camera's built-in pop-up flash and a tube which carries the light from The Flash and to your white diffusion material which is located near the slide to be copied.

 

[petrochemist]

You might be able to use the camera's built-in pop-up flash and a tube which carries the light from The Flash and to your white diffusion material which is located near the slide to be copied.

An angled mirror to send the light onto the diffusion material should work too, if you get the alignment right.

 

[Solarflare]

Tubes are fine with short focal length lenses, but don't do much with longer lenses.

And yet I use extension tubes on my Zeiss Makro-Planar 100mm f2 just fine. Just needs to be a longer tube.

If that's true, why do lens designers use such complex designs, more than 10 elements is now quite common, yet the earliest cameras used single element lenses.

Number of elements doesnt matter.

Output of a lens matters.

Lenses of just one element havent been used in early cameras, but in very cheap ones, like the Holga.

Cheaply made extra glass will certainly degrade the image, but well made optics do not automatically cause degradation.

A lens element will obviously never have zero influence on the light.

 

[petrochemist]

Filters = glass. Extra glass = increased image degradation.

If that's true, why do lens designers use such complex designs, more than 10 elements is now quite common, yet the earliest cameras used single element lenses..........

Because they're forced to design lenses with a fixed flange-to-focal plane distance.

Even large format lenses which don't have a fixed flange distance use multiple elements. Extra elements are used to reduce spherical aberration, coma, chromatic aberration... The need for correction often increases dramatically when fast glass is wanted.

There are good reasons why lens design evolved to give the 'Cooke Triplet', 'Double Gauss', 'Biogon', 'Ultron' etc. which have nothing to do with the registration.

 

[petrochemist]

Number of elements doesnt matter.

Output of a lens matters.

Lenses of just one element havent been used in early cameras, but in very cheap ones, like the Holga.

The number of elements can matter considerably. Lenses designers don't just add a few more in for the sake of it. The do intensive calculations to work out the effect.

Single element lenses will always show chromatic aberration. The advantage of combining crown glass & flint glass to produce an achromatic doublet has been around for over 150 years. The 'french landscape lens' from this time used an achromatic meniscus lens but was effectively limited to F/16 by other aberrations.

Cheaply made extra glass will certainly degrade the image, but well made optics do not automatically cause degradation.

A lens element will obviously never have zero influence on the light.

Just as well or there'd be no point using lenses, but 'influence on light' is not necessarily degradation.

 

[Derrel]

Close-up made with 100-300mm f/5.6 AI-S with reverse- mounted Nikon 6T achromatic doublet close-up "filter" on front of lens. Hand held, shot back in 2013. There were a number of Nikon Zoom from the 1980s and 1990s which were designed with a special close-up range which was optimized for the Nikon 5T and 6T close-up lenses. The 100 to 300 is one such lens and the 6T fits perfectly in its 62 mm filter threads. However when the close-up lens is reverse mounted it becomes even better and you have a very flat field and virtually no chromatic aberration. As I recall this was shot basically wide open, and it was hand held. I think I could maybe have done better stopping down a little bit and using a tripod, and of course taping the dollar bill perfectly flat not just tossing it on the kitchen counter. As you can see the bill is curved upward on the right hand side of the photo.

 

[480sparky]

Filters = glass. Extra glass = increased image degradation.

If that's true, why do lens designers use such complex designs, more than 10 elements is now quite common, yet the earliest cameras used single element lenses..........

Because they're forced to design lenses with a fixed flange-to-focal plane distance.

Even large format lenses which don't have a fixed flange distance use multiple elements. Extra elements are used to reduce spherical aberration, coma, chromatic aberration... The need for correction often increases dramatically when fast glass is wanted.

There are good reasons why lens design evolved to give the 'Cooke Triplet', 'Double Gauss', 'Biogon', 'Ultron' etc. which have nothing to do with the registration.

I never said LF glass has single elements. I said LF glass has FEWER elements because they don't have a fixed flang-to-plane distance.

If the FFL of a SLR/DSLR camera is, say 45mm, how does a designer make a lens with a focal length shorter than 45mm? By design, it would have to be inside the camera itself, interfering with the mirror. So they add glass to force the back of the lens back out beyond 45mm in front of the focal plane.

 

[petrochemist]

Filters = glass. Extra glass = increased image degradation.

If that's true, why do lens designers use such complex designs, more than 10 elements is now quite common, yet the earliest cameras used single element lenses..........

Because they're forced to design lenses with a fixed flange-to-focal plane distance.

Even large format lenses which don't have a fixed flange distance use multiple elements. Extra elements are used to reduce spherical aberration, coma, chromatic aberration... The need for correction often increases dramatically when fast glass is wanted.

There are good reasons why lens design evolved to give the 'Cooke Triplet', 'Double Gauss', 'Biogon', 'Ultron' etc. which have nothing to do with the registration.

I never said LF glass has single elements. I said LF glass has FEWER elements because they don't have a fixed flang-to-plane distance.

If the FFL of a SLR/DSLR camera is, say 45mm, how does a designer make a lens with a focal length shorter than 45mm? By design, it would have to be inside the camera itself, interfering with the mirror. So they add glass to force the back of the lens back out beyond 45mm in front of the focal plane.

You said they had more elements to cope with the flange distance, but a basic retrofocus design can be built with two elements. So it's clearly not just for that reason.
Your earlier comment 'Extra glass = increased image degradation' is true when the extra elements are not well chosen, but in lens design extra elements are often used to reduce aberrations, giving less image degradation.

I wasn't aware you'd even mentioned LF lenses, but many of the old lenses I use are similar designs whether on LF or mirrorless - I've certainly used triplets on my A7ii this week and none of my LF lenses are more basic than that. I don't use my DSLR much anymore but there are certainly some very basic lenses I've used on it in the past (typically 100mm+ focal length so not needing retrofocus designs) A few of those I've played with have had designed elements removed specifically to introduce spherical aberration for a soft focus effect.