Standard 28mm lens or Enlarger lens for 2x to 4x?

[leinadbc]

Hi everyone,

It's my first time here.

I started macro not long ago, when I saw I could reverse my 50mm to make amazing pictures, I added a bit of equipement later on and now I need some advice.

I am currently able to get 2:1 ratio with my 50mm and extension, and 3:1 with a 180mm and a reversed 58mm at the end.

However, I was interested in buying a 28mm to get 2x and 4x with tube (those are my aprox calculations, based on the ratios I get with all of my lenses)

I was considering normal 28mm lenses in any mount before I came by here, and I was recomended the olympus zuiko, canon fd and nikon als for low cost lenses.

I now see there is also enlarger lenses, telescope lenses and much more techniques that could help me get that ratio, but the most important thing for me is that I want to be able to still take pictures handheld WITHOUT stacking, so from what I heard microscope lenses might not be ideal for that.

I am looking for cheap used gear (maybe 50$?) if that's possible, I might add more if I find something really worth it. I do pictures for fun, not money. I plan to shoot insects mostly.

My gear:
Nikon D600
180mm f2.8
50mm f1.4
helios 58mm f2
1.4x teleconverter (is that useful for macro?)
extension tube 60mm and soon a 2nd one ( Can I use both at the same time? Or maybe put a part of one at the end of the lens to act as a hood and use like 100mm of tube?)

reverse ring
and 72mm to 52mm step down ring... which does not fit my 52mm thread 50mm lens, I guess I need some sort of 52 to 52mm thing too

Here's an exemple taken with 50mm and 60mm of tube:



What's that in the center?

Thanks

[leinadbc]

Which Enlarger lenses are cheap and usable at f8-11?
Maybe I can use reversed 50mm ELs with 2 sets of tubes?

Will I get sharper images than by using my nikon 50mm f1.4 at f11?

[Artiii]

Hi,

I'm using an old 28mm Pentax lens with a set of extension tube (68mm) for 2x - 4x magnification. You can easily find on e-bay, it's very cheap and good. I use this lens mostly at f5.6, sometimes at f4 but f5.6 is diffraction limit for my setup.

Without stacking your DOF will be very limited even at f11, and at 4X magnification your effective aperture will be f55 ( Effective Aperture = Lens Aperture x (1 + Magnification) ). You can't get sharp results and enough DOF without stack.

Take a look at this;
http://zerenesystems.com/cms/stacker/do ... romicrodof

[ray_parkhurst]

The reference (not best but good) is Nikon 50/2.8. Should cost $25-$50.

[leinadbc]

The reference (not best but good) is Nikon 50/2.8. Should cost $25-$50.

Will it be better than my Nikon Af-D f1.4?

[rjlittlefield]

1.4x teleconverter (is that useful for macro?)

I'm assuming you mean a physically short lens that fits between the camera and another ordinary lens, normally used to increase the focal length of a telephoto.

Yes, this is quite useful for macro. For example, your 180 mm plus a reversed 58 gives about 3.1:1. Place the teleconverter on the camera behind the 180, and the new combo gives about 4.3:1. Further, it does this without changing your working distance, and while still allowing the use of automatic diaphragm (view open, stop down at the instant of exposure). A good teleconverter can be very helpful for getting more magnification. Some people say that the extra glass degrades your image, but the whole truth is more complicated than that. For discussion, see What does a teleconverter do and why might you use one?

What's that in the center?

The bright spot in the middle is glare. It probably results from stray light bouncing off the inside of the extension tube. Tubes are notoriously prone to this problem. It can be reduced a lot by adding masks and baffles made of black paper or flocking inside the tubes. The offending light came from outside the field of interest, so another aid is adding a tight fitting hood to the front of the lens to block light except from the subject area you care about. See HERE, panel 1, lower left.

I guess I need some sort of 52 to 52mm thing too

The normal "72mm to 52mm step down ring" will have a male 72mm thread and female 52mm. That's intended to allow the use of 52mm filters on your 72mm lens, but indeed it won't fit your other lens which also has a 52mm female thread. The device you need is a "reverse ring" with 52mm male threads on both sides, to go between the step down ring and your 50mm lens. The cheapest one I know is HERE.

I am looking for cheap used gear (maybe 50$?) if that's possible

Except for the reverse ring, I suggest not buying any more equipment at this time. The stuff you already have can do good work, so I think your resources would be best spent on figuring out how to use it well.

One key thing is to systematically try different aperture settings until you have a solid feel for what effect stopping down has on your images. What you'll find is that stopping down a little both gives more DOF and makes your images sharper (by reducing aberrations), but stopping down a lot makes them blurred (from diffraction). When you're not stacking, the trick is to identify the aperture setting that gives the best compromise between DOF and sharpness. That best compromise will vary depending on your application and personal tastes. However, the tradeoff between DOF and sharpness is limited by physics, not by lens design, so aside from stacking there's no "magic bullet" that will give you significantly more DOF at the same sharpness than what you currently have.

--Rik

[ChrisR]

What's that in the center?

It's sometimes called a "hot spot". Some lenses just DO do that when reversed, but often the problem lies in the reflections inside tubes and adapters. Look, ie with one eye, into the back of your tubes+reversed lens. If you can see anything reflecting light around, take measures to stop it.
Those can be a disc of black paper with a hole which forms a mask, or black flocking material such as Protostar.

but the most important thing for me is that I want to be able to still take pictures handheld WITHOUT stacking, so from what I heard microscope lenses might not be ideal for that.

I misread - missed the "not" and wrote a retort - which I've now modified!

DOF is deternined by the Effective Aperture, for a given magnification. How you achieve that aperture makes no difference. Microscope objectives can have the largest apertures once you get to about 4x and above. Below that magnification their working distance is unfavourable.

Effective aperture is normally given by
(Marked aperture x (Mag +1)) for a camera lens
or
Mag/(2 x NA) for a microsope objective.
(Some lenses are asymmetrical which alters the numbers a bit)

[ray_parkhurst]

The reference (not best but good) is Nikon 50/2.8. Should cost $25-$50.

Will it be better than my Nikon Af-D f1.4?

Maybe, but more likely the same. The main difference will be that the smaller enlarging lens will make lighting easier. You still need to buy a reversing ring, a 52mm...40.5mm in this case.

One thing to keep in mind is that you can beat the physics (sort of...) of the DOF versus diffraction tradeoff through downsizing. Each 2x downsizing gives you 2 stops of additional aperture from diffraction perspective, but the same DOF. So if you are downsizing your images for Web publishing you can stop down more than if you are looking at them full size.

[leinadbc]

Thanks for all your replies. I think that glare or hot spot might be because the rear element on my nikon 50mm is very exposed to the light, since it's at the very end of the lens.

I will use my 58mm for better results, and I'll try to make some kind of hood for it. I bought that adapter, well a 49 to 52mm, since that 58mm has a smaller filter size.

I will keep experimenting with different appertures

thank you

[ChrisR]

and I'll try to make some kind of hood for it.

Extension tube

[leinadbc]

and I'll try to make some kind of hood for it.

Extension tube

Exactly

[leinadbc]

A fly and a damselfly

Both taken with my 180mm + reversed 58mm, I think it's not that bad, but I might have to get my d600's sensor cleaned...

thanks for your help!