[kurt1968]

Hi
i have the superb fa 135mm f2.8.
Was wondering to buy a 5$ step down ring (52 to 49mm) and put a cheap M 50mm 1.7 in front of it.
Would this setup work out fine ?
Was not especially targetting insects , rather macro of all kinds of stuff .

[boriscleto]

https://www.pentaxforums.com/forums/54-pentax-lens-articles/152336-cheap-macr...lose-work.html

[lister6520]

Before I finally made up my mind and bought a 90mm Tamron I relied on two setups, depending on what I needed.

For outdoors I used a 50mm F2 (standard lens from film era) which I mounted on between one and three 'extension tubes' which were actually cheap teleconverters I got on eBay and removed the glass from them. I could get more than 1:1 magnification (I thin some 2.5:1 but can't remember for sure). This allowed me to keep the lens a couple of inches or so from the subject.

For more extreme magnification I used a reversed 28mm F2.8 lens (from 1980s). I mounted this using a reversing ring mounted onto a cheap extension tube set I bought on eBay (about $20). This particular extension tube had the camera and lens mounts attached by a screw thread (as did the tubes between themselves) so I could screw in the reversing ring directly to the tube instead of the lens mounting piece.

This gave me some rather extreme magnification and surprisingly sharp images. The downside is that depth of field is very shallow and you have to get very close to the subject, about an inch or so I think. The other thing is that you no longer have auto iris control so you need to focus with the aperture full open and then turn to the desired aperture just before shooting.

I still actually use this setup occasionally rather than the macro lens as it can give me much higher magnification.

If you want to go to more extreme magnification like shots of tiny bugs and such you can go for a microscope with a camera adapter. I bought a 'student' microscope for about $150 new on eBay (you can get better used ones for less) and an adapter tube for another $15.

This is a photo of a hard disk head taken with K-30 through the microscope.It is just about a millimeter across. It is actually a composite of about 50 images which were then focus stacked.

To give an idea of the scale this is a photo of the same head shot with the Tamron Macro at 1:1 with a 10 cent coin for scale. The photo is actually cropped to half its original size (effectively magnifying it 2 times).

This is a mosquito also through the microscope and focus stacked.

And a fly

If you want to shoot bugs in this way then they have to be either dead or drugged, unless you can otherwise convince them to sit still while you shoot the 50 or so photos.


This is the CCD from a Canon compact P&S camera, actually just a corner of it. The whole sensor is about 5mm across but the photo is showing only a tiny fraction of that. You can easily discern the actual RGGB photosites in the upper left part of the photo.

[Na Horuk]

There are a couple threads about "macro by any means possible" with many great tips. But I would still suggest you get a dedicated macro prime. Older ones are pretty affordable. They come in f2.8 and f4, some with a macro extension tube to get true 1:1 macro.
Cant help you about reversing lenses, just keep in mind how a step up ring connects (male-female threads). I think a step up/down ring is different from a lens reversal ring. Take a look at some photos of these products to make sure.

[dms]

The setup you describe will likely give you about magnification=2.5. Do you really mean to be at this (huge) macro area? More typically m=0.5 is the limit before it becomes quite tough. The "cheap" 50mmf 1.7 is one of the best lenses around (in general), and is excellent on extension tubes or (for example) w/ vivitar macro 2x teleconverter (much better than the 50mm f1.4 for macro).

[Canada_Rockies]

The step ring you need is a double male threaded filter ring that allows you to mount the two lenses front to front. The focus distance is the 43+ mm register distance (mount to sensor/film) used by Pentax. For closer, use a Canon which has a shorter register distance. For longer use a 645, 67 or large format lens reversed. The multiplication factor with lens + reversed lens is the ratio of the two focal lengths, with a bit of fudge factor to take care of the mount thickness.

A macro rig that I used for 2x was a SMC Pentax M 28/3.5 on a 52 mm mount adapter (gives the filter threads out front and K mount on the back) and a 52-49 step ring to mount the 28. This was 2.1x on the sensor/film. A 50mm reversed on the same rig gives about 1:1. This is an inexpensive way to get into macro work, and gives excellent optical results.

[dms]

BTW while I don't use reversed lenses (I am not doing m>1) those lenses should (likely) do excellently together. But from what I know/read (and I have 5 macro lenses for my 3 camera systems--so it was/is of interest to me) your technique must be excellent, and other equipment must be adequate/appropriate. Since you asked the question I suspect you will be on a steep learning curve w/ the stacked lens arrangement you asked about.

[mtngal]

I've played around with an old 135mm lens and a 50mm f1.4 reversed in front of it on a reversing ring (different than a step up/step down ring). It works, but I found it frustrating and not all that useful for anything without stacking. I also tried reversing a 24mm f2.8 lens and while that provided even more magnification, I found it more frustrating than I was willing to deal with (and I would need better software than the stacking options in CS6). I did better using a very poor quality 2X TC that had belonged to my father, taking the glass out of it and making it into an extension tube.

If you already have both lenses then the reversing ring is cheap enough that it would be worth trying out. The other thing to think about is light and a tripod. I should get out my extreme macro stuff again, now that I have macro focusing rails. I think that will help speed things up - extreme macro is something to do when you have lots of time, it's slow-going.

[kurt1968]

ok thx guys.
Think i will look out for a dedicated macrolens.
Tamrons seem to be very good.

[Nass]

Kurt, it'll work just fine if you want to get your feet wet at about 2.5:1 - see Coupled Reverse Lens

[kurt1968]

Kurt, it'll work just fine if you want to get your feet wet at about 2.5:1 - see Coupled Reverse Lens

great link , thx Nass

[audiobomber]

My favourite cheap macro solution is a Raynox adapter. Good subject distances, medium to high magnifications, versatile, maintains auto exposure (and even AF, but who cares about AF for macro?). IQ with a Raynox is as good as a base lens + reversed lens IME, but subject distance is hugely better and you don't lose AE.

The Raynox DCR-150 on a 135mm would get you from 1:1.7 to around 1:1 magnification with a 135mm. The DCR-250 would get significantly beyond 1:1, but tighter subject distances.

[kurt1968]

yes a Raynox might be a good solution

[stevebrot]

My favourite cheap macro solution is a Raynox adapter. Good subject distances, medium to high magnifications, versatile, maintains auto exposure (and even AF, but who cares about AF for macro?). IQ with a Raynox is as good as a base lens + reversed lens IME, but subject distance is hugely better and you don't lose AE.

The Raynox DCR-150 on a 135mm would get you from 1:1.7 to around 1:1 magnification with a 135mm. The DCR-250 would get significantly beyond 1:1, but tighter subject distances.

Glad someone finally suggested the Raynox auxiliary lenses. They are typically coupled to a close-focus zoom and provide fairly stunning results.

To return to the original post:

• Yes, an extension tube setup will work. You will probably want a set of three with aperture coupling.
• You might also want to consider bellows
• Your 135mm lens should provide adequate working distance
• Lighting is a huge issue. The extension needed for high magnification decreases the working f/number so that even bright ambient light. The conventional solution is a ring flash mounted to the front of the lens or off-camera flash(es) positioned either side of the lens. Unconventional solutions I have seen include various foil-lined snorkels for on-camera flash directing light forward. I have also seen examples where people used powerful LED minilights (e.g. hiker's headlamp) as a light source.
• Focusing is an issue due to limited DOF, dim image in viewfinder, and the limited usefulness of the focus ring at high magnifications. A focus rail is the traditional solution (moves camera/lens as a unit to focus).
• DOF is an issue due to the high magnification. Focus stacking is the best current answer. Again, a focus rail is good.

The first three points are the most important. The last three are things you will find during your first session.

Have fun!!


Steve

[beachgardener]

For sale, i have a cheap zoom with macro function if that is any use to you
https://www.pentaxforums.com/forums/24-photographic-equipment-sale/243443-sal...spherical.html