[Philoslothical]

A lot of the overall IQ question lays with the host lens used. A Raynox, or any other corrected diopter lens, will produce better results on a better host lens, simple as. Some people use a Raynox on the end of a dedicated macro lens, just to push the magnification further without losing light. They get some incredible results. I think it's realistic to expect the general quality and character of your host lens, rather than trying to compare it to a dedicated macro lens. Sorry if that's not much help.

[luftfluss]

Image quality is going to depend more on the lens to which you attach the Raynox rather than the Raynox itself. Image quality would be better with, say, a DA 300/4 than a Tamrom 70-300. That said, I've been quite happy with the Tamron/Raynox combo for years.

You'll lose some AF ability with the Tamron/Raynox combo. Not an issue for me, because macro (IMO) is generally a MF endeavor, anyway.

Edit: heh, Philoslothical beat me to it...

[epqwerty]

From my personal exoerience i would pair it with the 150 i have a sigma 70-300 with a 250 it isnt useable at 300 due to the lack of working distance. The 150 will be more useable across the entire range. As for hints do not use af with the 250 at 300mm or anything at all the working distance.

[RioRico]

I cover the Raynoxi and other close-up adapters a bit in https://www.pentaxforums.com/forums/pentax-lens-articles/152336-cheap-macro-b...lose-work.html

I have a few sets of cheap +1+2+4 dioptre adapters, a few +10dpt's (but not an Opteka) and a Raynox DCR-250. I know the Raynox is optically corrected and the others aren't, but they don't bother me much. Anyway, here are how the numbers work.

A lens' dioptre measurement is the inverse of its focal length, in meters. A +1dpt glass has a focal length of 1m or 1000mm; +2dpt= 500mm; +4dpt= 250mm; +8dpt (like the Raynox DCR-250)= 125mm. When stacking glass, just add the dioptres. So a +2dpt stacked on a +8dpt gives +10dpt. We use this dioptre-addition to calculate the effective focal length of any optics combination. A +10dpt glass on a 100mm lens is thus 10+10= 20dpt = 1000/20mm= 50mm.

And yes, we can treat stacked adapters like a lens. I can (and do) put a +2dpt onto my Raynox DCR-250 and mount them on an M42 bellows for an effective 100/2.5 optic. A bit soft and romantic, too! I'll let y'all figure out how to compute effective apertures, eh?

To calculate the magnification of any lens plus adapter, use:

M = F*D/1000

where M is magnification, F is host lens focal length, and D is dioptre of the add-on lens. Rewriting that to find D or F, we get

D = 1000*M/F

F = 1000*M/D

A +8dpt Raynox (or whatever) on a 100mm lens gives M = 100*8/1000 = 0.8x. On a 200mm lens, M = 200*8/1000 = 1.6x. Et cetera.

So magnification depends on the adapter's dioptres and the lens' focal length. Working distance is a different matter -- that depends entirely on the adapter's dioptres. Here is a table of working distances:

+1 >> 20-38" (500-950mm)
+2 >> 13-20" (330-500mm)
+3 >> 10-13" (250-330mm)
+4 >> 8--10" (205-250mm)
+5 >> 6.5-8" (165-205mm)
+6 >> 6-6.5" (153-165mm)
+8 >> 5" --- (127mm)
+10 > 4" --- (102mm)

And here's what all this boils down to:

* A close-up adapter can dramatically thin a shot's DOF.
* Close-up adapters don't do diddly-squat on short lenses.
* Stronger dioptres and longer lenses give more magnification.
* The stronger the dioptres, the closer the working distance.

Anyway, I have lots of fun with such cheap adapters, and with the Raynox too.

[Culture]

This might be a stupid question but why not just use the macro capabilities of the Tammy or Sigma. What is the difference using a Raynox

[Philoslothical]

This might be a stupid question but why not just use the macro capabilities of the Tammy or Sigma. What is the difference using a Raynox

It's not a stupid question. If you mean the 70-300mm in your signature, it can only reach 1:2 (half life size), but if you put a Raynox 150 on the end of it, you can get anywhere from 1:3 (at the 70mm end!) to 1.35:1 (a bit stronger magnification than a typical dedicated macro lens) at the 300mm end. The latter will have some distortion, but hey, this is a cheapie way of getting that close.

With a Raynox 250 on the same host lens, you're looking at ~1:2 at the 70 end (the same magnification as fully extended and fully focused in, without the Raynox) to 2.4:1 magnification at 300mm.

In both cases, you'll actually get a little more, if you put the lens in macro mode and fully focus in. Expect the distortions to be pretty wild around the edge of the frame. Keep in mind that these distortions are caused by the cheap host lens, not the Raynox. The Raynox is just magnifying the effect. If used on a quality host lens, the effect is much better. There are some pictures in the Raynox club thread where it was used on a dedicated macro lens, to great effect (and easily exceeding 2:1 magnification).

These +dioptre lenses are an easy way of getting close to a subject without losing light, and without spending much money, but there are better, cleaner ways of doing it. They just take more patience, better light or flash, or in the case of actual macro lenses, more cash.

[el baroda]

Message for Luftfluss -

I received my Raynox DCR 150 yesterday. When I attach it to my Tamron 70-300mm, my working distance is only about 4 inches (at 300mm, focused at infinity), far shorter than the 10" that you get from the same combo. I would appreciate very much your comment/advice as to why my working distance is so short. Thanks in advance and best regards.

[newarts]

Message for Luftfluss -

I received my Raynox DCR 150 yesterday. When I attach it to my Tamron 70-300mm, my working distance is only about 4 inches (at 300mm, focused at infinity), far shorter than the 10" that you get from the same combo. I would appreciate very much your comment/advice as to why my working distance is so short. Thanks in advance and best regards.

I am baffled at this result. It is what you'd expect from a Raynox 250. Maybe that's what you received. What's the apparent magnification at 300mm, infinity focus?

PS. You should expect about 8.3" working distance with the 150.

[RioRico]

I am baffled at this result. It is what you'd expect from a Raynox 250. Maybe that's what you received. What's the apparent magnification at 300mm, infinity focus?

PS. You should expect about 8.3" working distance with the 150.

Quite right. How is the optic marked? Mine says RAYNOX MACROSCOPIC LENS Model M-250 around the front.

[el baroda]

It is definitely the 150 model, not the 250, and I'm getting much less than 8.3" working distance. I set the Tamron at 300mm, macro mode and infinity. I also set my camera on Manual mode and use flash on bracket. Am I doing something wrong? Really looking forward to comments and suggestions. Thanks.

[Philoslothical]

Odd. There's really nothing you can do wrong. The working distance would be the same at any focal length, as in the same for a 50mm prime as your 70-300mm zoom. It's just the magnification that changes.

[el baroda]

Hi Philoslothical. Thanks for your response. With all respect, I am now more confused. I will play with my combo this weekend and see where the problem, if any, lies. My "problem" really is my working distance being less than what I've read here. Happy Easter in advance.

[Philoslothical]

My "problem" really is my working distance being less than what I've read here.

Indeed. What I was getting at is that all these +dioptre addon lenses have a fixed working distance dependent on their strength. A +4 dioptre lens should focus about 10" from the subject regardless of which host lens is used. RioRico posted the chart above:

+1 >> 20-38" (500-950mm)
+2 >> 13-20" (330-500mm)
+3 >> 10-13" (250-330mm)
+4 >> 8--10" (205-250mm)
+5 >> 6.5-8" (165-205mm)
+6 >> 6-6.5" (153-165mm)
+8 >> 5" --- (127mm)
+10 > 4" --- (102mm)

As for why you're getting results inline with a +8 or +10 dioptre lens, I have no idea.

[RioRico]

Something is wrong, and it's not you.
You're doing everything right.
If it's not you, the cause is elsewhere.
A logical conclusion: the Raynox is mismarked.
If anyone has a better idea, whip it out.

[el baroda]

G'day, mates. I did some more test shots today and found it almost impossible to get a decent photo. The working distance (yes, it's 8") is too short for photographing insects and the depth of field is too shallow. I am thinking of getting a macro rail but working with a tripod is not easy either. I guess I'll have to practise more. Has anyone used a macro rail (slider)? Thanks for your help and Happy Easter to all.