Reversing Lens question

clockwurk · Sep 10, 2011

Most of the tutorials I see online use a 50m f/1.8 reversed. Is there a particular reason for this other than its a cheap lens?

Would I be able to get more of a magnification with something like a 100mm macro reverse? Or would it be the same?

I currently have experimented with a 100mm macro on a full set of extension tubes and I'm very happy with it. But I keep seeing shots that seem to get much closer than setup above. I would like to get tips on how I can get more magnification with my current setup.

Thank you in advance

Overread · Sep 10, 2011

The 50mm f1.8 reversed is a popular option because, as you say, its cheap. It's a cheap, yet good lens which can be turned to a good use with several macro methods, such as reversing. I think, however, if you want to go greater when you already have a 100mm macro lens you've a few options to consider:

1) Reversing a shorter focal length lens onto the 100mm macro. A coupling ring between two lenses would let you reverse a shorter focal length lens onto the 100mm macro; the rough math for this is (note I'm not aware if the magnification of the 100mm would add to the end result or not, I've never tried this and I typically encounter it with non-macro lenses when its used).
Focal length of the lens attached to the camera - divided by - focal length of the reversed lens = magnification : 1
So say a 35mm would give around 3:1 magnification.

2) Extension tubes - you've used them and can get so far, but for a 100mm macro to get to 2:1 or 3:1 you are starting to get way too much tube length need to be reasonably feasible.

3) Teleconverters - a simply increase by the teleconverter capacity - a 2*TC would jump you to 2:1. The added bonus is that teleconverters are about the only method of increase that will retain the lenses full normal properties; you still have infinity focus and your minimum focusing distance is unchanged. However not all lenses work with all teleconverters so a compatibility limitation might be present. If possibly I'd strongly encourage a 1.4TC as I use one myself almost all the time - almost no degradation for a good gain in magnification.

4) Close up lens attachments/macro filters/diopters - these are often slated as being a poor choice because many people that use them early on use the cheap kits. These are made with lowgrade single element glass and typically work, but cost a lot in image quality. There are however more powerful options which are of a much higher grade and give very tiny degradation (to the point where its often not noticeable in normal shooting and processing.
The Raynox series, starting with the DCR 150 and 250 would give you a boost, whilst options like the MSN 202 and 505 would give you big boosts in magnification.
They work the same way extension tubes do, however they give more magnification (per unit of diopter power) on longer focal length lenses (unlike tubes where the greater magnification gain per tube length is on shorter focal length lenses).

Personally I like the fast to attach Raynox close up lens attachments and, considering that you're already dabbling in higher magnifications I would say start with the DCR 250 (diopter power 8) at least, but the MSN 202 (diopter power 25) might be a better bet for getting a good jump in magnification.

I use the 250 myself, but I've yet to experiment with the others (chances are I will at some point, however I jumped on the canon MPE 65mm macro as my main higher magnification lens setup).

clockwurk · Sep 10, 2011

This is great! Thx Overread!

Josh66 · Sep 10, 2011

Overread said:
1) Reversing a shorter focal length lens onto the 100mm macro. A coupling ring between two lenses would let you reverse a shorter focal length lens onto the 100mm macro; the rough math for this is (note I'm not aware if the magnification of the 100mm would add to the end result or not, I've never tried this and I typically encounter it with non-macro lenses when its used).
Focal length of the lens attached to the camera - divided by - focal length of the reversed lens = magnification : 1
So say a 35mm would give around 3:1 magnification.

Yes, that's how I've always figured it too. When I was doing this a lot, I used to use a 50 reversed onto the 70-200 (@200) for 4:1.

Another tip I read somewhere when doing this, is that you should mount the lens with the smaller maximum aperture to the body. This is because you only have aperture control over one of the lenses, and it is supposedly better for that to be the one with the smaller aperture - which is usually the longer one anyway, so it makes sense as far as weight goes too.

You can get some pretty sweet shots with a setup like that, but man is it hard to work with. At f/32 my DOF was about 1mm.