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08-17-2009, 05:45 AM   #1
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Tamron 2.8 90mm and going past 1:1?

I recently bought myself a tamron 2.8 90mm macro. My only problem is that I am a little addicted to macro shots. Have seen some impressive results at 2:1 to 3:1. I need some advice on how to get more mag. I have some options and would like some advice.

Some sites suggest different methods in doing so. I am considering adding my 50mm 1.4 to the 90mm macro useing a 55 and 49mm macro coupling ring. However most sites state that coupling works best with normal lenses not macros. Is this true? Not all the research I have done on the subject suggests useing only normal lenses.

I can also buy manual extension tubes or the vivatar 2x tc. The coupling ring would be dirt cheap. Only 8 bucks for the 55-49 male to male coupling ring. Not intrested right now in a bellows. However thats another option. Any suggestions to max out my tamron 90mm? Anyone have some experience using it coupled to a 1.4 50mm?

08-17-2009, 04:03 PM   #2
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FWIW, I've heard of people taking the glass out of a teleconverter and using that for an extension tube. I've been tempted to try that with my cheapo 2x tc, but haven't had the guts (I don't like to reduce things from a known-working state to a possibly-working state) to try it yet.
08-17-2009, 04:44 PM   #3
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QuoteOriginally posted by Xcom Quote
I recently bought myself a tamron 2.8 90mm macro. My only problem is that I am a little addicted to macro shots. Have seen some impressive results at 2:1 to 3:1. I need some advice on how to get more mag. I have some options and would like some advice.

Some sites suggest different methods in doing so. I am considering adding my 50mm 1.4 to the 90mm macro useing a 55 and 49mm macro coupling ring. However most sites state that coupling works best with normal lenses not macros. Is this true? Not all the research I have done on the subject suggests useing only normal lenses.

I can also buy manual extension tubes or the vivatar 2x tc. The coupling ring would be dirt cheap. Only 8 bucks for the 55-49 male to male coupling ring. Not intrested right now in a bellows. However thats another option. Any suggestions to max out my tamron 90mm? Anyone have some experience using it coupled to a 1.4 50mm?
As you need to increase the distance between the lens rear element and the camera mount you have the following options:

Manual or Auto Extension tubes (Pref Auto)

Old 2x extender minus glass

Helicoil Extender (extension tube with a helical screw thread to vary tube length)

Manual or Autobellows

Or all of the above

You can modify the dual cable release of the Autobellows to connect the old cable release to the newer electrical releases by using a small inline push switch and some heatshrink tubing.

The hi mag results obtained from the largest extension combination are beautiful as long as nothing moves and that includes passing traffic.

Have fun

David
08-17-2009, 04:46 PM   #4
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QuoteQuote:
FWIW, I've heard of people taking the glass out of a teleconverter and using that for an extension tube. I've been tempted to try that with my cheapo 2x tc, but haven't had the guts (I don't like to reduce things from a known-working state to a possibly-working state) to try it yet.
I did that before... Wasted a couple of tc's because didn't know how to take the group out correctly turns out, you don't even need to open the screws - just screw off the rearmost glass element without opening the mount, and everything else will fall out with it.

08-17-2009, 07:33 PM   #5
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QuoteOriginally posted by Xcom Quote
I recently bought myself a tamron 2.8 90mm macro. My only problem is that I am a little addicted to macro shots. Have seen some impressive results at 2:1 to 3:1. I need some advice on how to get more mag. I have some options and would like some advice.

Some sites suggest different methods in doing so. I am considering adding my 50mm 1.4 to the 90mm macro useing a 55 and 49mm macro coupling ring. However most sites state that coupling works best with normal lenses not macros. Is this true? Not all the research I have done on the subject suggests useing only normal lenses.

I can also buy manual extension tubes or the vivatar 2x tc. The coupling ring would be dirt cheap. Only 8 bucks for the 55-49 male to male coupling ring. Not intrested right now in a bellows. However thats another option. Any suggestions to max out my tamron 90mm? Anyone have some experience using it coupled to a 1.4 50mm?
Tubes are the best way to reach higher mag ratios w/o affecting IQ. If you want to preserve AF then it seems to get harder for Pentax mounts. Normally Kenko AF, also called auto tubes work fine but seems they are no longer around for Pentax.

I did find this set of Pro Optics Auto Tubes:

POAETPXK Pro Optic Auto Extension Tube Set for Pentax-KPR Mount, 3 Tubes.

Don't know anything about those tubes still, it might be worth checking into them. Better than removing the glass from a TC.

Reversing works OK but you will lose IQ. If you already have the lenses and just want to see what you can do, then heck, spend the $5 on a reversing ring and go for it...it's a lot of fun. But if you want the best IQ then tubes are the best option.

Almost forgot, if you can live with MF and prolly manual exposure as well then just buy a set of cheap tubes with no electric contacts. I had a set for my canon gear and they were a lot of fun as well and a set can be had under $20 shipped.
08-17-2009, 09:30 PM   #6
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QuoteOriginally posted by clawhammer Quote
FWIW, I've heard of people taking the glass out of a teleconverter and using that for an extension tube. I've been tempted to try that with my cheapo 2x tc, but haven't had the guts (I don't like to reduce things from a known-working state to a possibly-working state) to try it yet.
Trust me, It doesn't work

It just isn't possible to get shots like this like this.

Oh, that is how I got that shot, using a 35mm f2.0 Super Tak



Xcom, I know where there are some NEW Genuine Pentax Lens Reverse adapters. Both 49, and 52mm. They'll allow you to get right up to the plant. However the DOF will be extremely shallow, making it almost impossible to focus, without a Macro Slider.
With the lens soo close to the plant you pretty much also need some Off Camera lighting source. Often even just to focus
The camera it's self causes a pretty dark shadow at times.
08-17-2009, 11:13 PM   #7
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QuoteOriginally posted by clawhammer Quote
I've heard of people taking the glass out of a teleconverter and using that for an extension tube.
I have 2 PKA extension tubes that used to be 2X tele-converters. Once cost me nothing (I bought a polarizer second-hand and the seller threw the TC in for free). One cost me $10 (also used).

Each took me about 10 minutes to remove the optics.

I like them so much I sold my genuine Pentax auto tube set.

I can use them with my Tamron 90mm macro 2.8. No auto focus. But auto exposure works.

Last edited by SOldBear; 08-18-2009 at 12:39 AM.
08-17-2009, 11:59 PM   #8
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There is another way...

There is another way that results in less light loss than ext tubes... put a raynox 150 or 250 on the front of the tammy 90mm.

Some where I had pics of the raynox 250 on the front of my Vivi series 1 105... I will see if I can find them.

08-18-2009, 02:05 AM   #9
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I've removed the lenses in a Kenko 2x converter that has both screwdrive autofocus and SDM. It works very well, even with autofocus. I've posted some examples before on the forum, but it might be easier for you to find them on my blogg link (see below), some ant and spider with the Kenko-tube (ex-converter) on the SMC Pentax-DFA 100mm 1:2.8 macro. As far as I could estimate, this got me to 2:1 magnification. I was surprised that the AF worked so well.
08-18-2009, 05:05 AM   #10
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I don't understand why people are advising to remove the elements from a TC to get beyond 1:1 macro. Why not just use the TC with the lens?

I use a Raynox 250 with my D FA 100 macro to get about 2.5:1. Working distance is cut down to a couple of inches from the front element and DOF is shallow necessitating small apertures, but quality is very high and I don't lose light or auto-exposure.

Last edited by audiobomber; 08-18-2009 at 05:18 AM.
08-18-2009, 07:32 AM   #11
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QuoteOriginally posted by audiobomber Quote
I don't understand why people are advising to remove the elements from a TC to get beyond 1:1 macro. Why not just use the TC with the lens?
Reduction of IQ.
08-18-2009, 08:38 AM   #12
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QuoteOriginally posted by audiobomber Quote
I don't understand why people are advising to remove the elements from a TC to get beyond 1:1 macro. Why not just use the TC with the lens?

I use a Raynox 250 with my D FA 100 macro to get about 2.5:1. Working distance is cut down to a couple of inches from the front element and DOF is shallow necessitating small apertures, but quality is very high and I don't lose light or auto-exposure.
Yes, reduction of IQ.
Add to this: using the TC as it is means larger light loss than if you use a tube of the same length. This is for instance why Tamron offered both a dedicated 2x converter and a dedicated tube to the Tamron SP 90mm f2.5 macro. With the tube you got a 90mm f3.75, with the converter a 180mm f5.0. One faster option, one with more reach. In both cases the 1:2 lens becomes a 1:1 lens. I do use also a 1.7x converter for the DFA 100mm macro lens, which gives me longer reach for butterflies etc, with some IQ losses as trade off, but it does not give me more than 1:1. For this, I need the tube. And while I had several sets of tubes without AF, even some with the KA contacts, I wanted to try AF with 2:1. It worked.

Using such a rainox front element adapter or whatever it is called and going down to a few inches of close focusing distance...that wont easilly catch any bugs without scaring them away will it?
08-18-2009, 09:00 AM   #13
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I've used my 25mm Kenko uniplus tube with the tamron 90 with pretty good results. DOF is so shallow as to almost require a tripod, I found handholding to be impossible, but I've gotten OK results with a monopod. A few samples:
Bearded Iris petal


Close up of an ornamental grass head.


I've been massively busy lately and haven't been able to go out shooting like I want, but one of these days I'm going to try to catch some dragon or damsel flies with this setup.
As others have said Kenko has stopped making the uniplus tube for K mount, but they can be found on eek bay with some searching. I suggest very strongly that you get an auto aperture extension tube, wether it be Kenko or some other. Fiddling with stop down metering and the like is VERY MUCH a pita with an extension tube/macro lens rig.

NaCl(macro, macro is fun)H2O
08-18-2009, 10:41 AM   #14
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QuoteOriginally posted by Douglas_of_Sweden Quote
Yes, reduction of IQ.
Add to this: using the TC as it is means larger light loss than if you use a tube of the same length. This is for instance why Tamron offered both a dedicated 2x converter and a dedicated tube to the Tamron SP 90mm f2.5 macro. With the tube you got a 90mm f3.75, with the converter a 180mm f5.0. One faster option, one with more reach. In both cases the 1:2 lens becomes a 1:1 lens. I do use also a 1.7x converter for the DFA 100mm macro lens, which gives me longer reach for butterflies etc, with some IQ losses as trade off, but it does not give me more than 1:1. For this, I need the tube. And while I had several sets of tubes without AF, even some with the KA contacts, I wanted to try AF with 2:1. It worked.

Using such a rainox front element adapter or whatever it is called and going down to a few inches of close focusing distance...that wont easilly catch any bugs without scaring them away will it?

The difference between extension tubes and a tc is, that the latter increases focal length. Thus you reach the same magnification at a wider distance, which is especially important with high magnifications beyond 1:1.

Ben
08-18-2009, 11:21 AM   #15
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QuoteOriginally posted by Douglas_of_Sweden Quote
I do use also a 1.7x converter for the DFA 100mm macro lens, which gives me longer reach for butterflies etc, with some IQ losses as trade off, but it does not give me more than 1:1.
I don't have a TC but that's not what I was told. I thought you could get 1:1 with a longer working distance, or keep the same working distance and get a multiple of the magnification (i.e. a 1.4X TC would give 1.4:1 at the DFA 100's normal close focus distance.)

Yes, the Raynox 250 is a bit close for insects on the end of a macro lens, but with the right subject it works well and provides macro significantly beyond 1:1 (I believe about 2.5:1) and automatic operation, so it has its advantages.
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