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08-05-2016, 08:31 AM   #16
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The big downside of lens extension is loss of light. Of course the slimmer the extension, the less light loss.

So supplementary close-up lenses have their place.. The Raynox close-up lenses I just pulled up on the auction site, seem to be nothing like the usual sets. They look to be a single auxiliary lens, but maybe those are not the ones wpresto is referring to. They also were not what I call inexpensive.

08-05-2016, 09:28 AM   #17
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QuoteOriginally posted by goatsNdonkey Quote
The big downside of lens extension is loss of light. Of course the slimmer the extension, the less light loss.

So supplementary close-up lenses have their place.. The Raynox close-up lenses I just pulled up on the auction site, seem to be nothing like the usual sets. They look to be a single auxiliary lens, but maybe those are not the ones wpresto is referring to. They also were not what I call inexpensive.
The two-lens set, with quick-mount ring, retails for about $120* from B&H. Does that price seem high? You can purchase just one of the lens units but the cost savings is, IMHO, insignificant so I recommend getting the two-lens kit.

*I just went to the B&H site and the current price is just under $110.
08-05-2016, 12:35 PM   #18
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I would suggest going with tubes on your existing lenses. Even though your lenses are not corrected for macro distances (especially spherical aberration) stopping down will solve most of that. The performance you will get from tubes will be quite good. Some macro lenses offer a flat subject field but using tubes on a non-macro lens will yield a curved subject field. Stopping down will increase your DOF and give the appearance of a flat field. I've been using tubes on my 67 for decades. Sorry to be so wonky on this.
08-05-2016, 01:02 PM - 1 Like   #19
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QuoteOriginally posted by desertscape Quote
I would suggest going with tubes on your existing lenses.
This is probably the direction I'll go, I just need to spend some time figuring out which tube lengths will give me what amount of reduction of MFD.

QuoteOriginally posted by WPRESTO Quote
The two-lens set, with quick-mount ring, retails for about $120* from
I wonder how the rayox will fair on the medium format lenses since I will have to buy the adapters. I already have a filter sets for a cokin GND and some 8 stop filters and I just don't like fiddling with them, cleaning them and so on.

---------- Post added 08-05-16 at 01:12 PM ----------

QuoteOriginally posted by mikeSF Quote
I bought a set of 645 extension tubes and the shortest one is perfect for breaking the min focusing distance barrier
I can't very well argue with that since you've already done the testing for me!

QuoteOriginally posted by Bob L Quote
Also worth a mention is an -A 75mm/2.8 with the 58mm reverse adapter.
Are you talking about reversed on another lens or just reversed alone? I have wanted the 75mm to toy with f2.8 max aperture on the medium format.

08-05-2016, 01:28 PM   #20
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QuoteOriginally posted by littledrawe Quote
Are you talking about reversed on another lens or just reversed alone? I have wanted the 75mm to toy with f2.8 max aperture on the medium format.
The reverse adapter allows a lens to be installed onto the body backwards. There are two reverse adapters for the 645 (58mm and 67mm) and they have a body mount on one side and a male filter thread on the other. The font side allows lockable rotation to permit the lens to be orientated with the aperture ring topside for ease.

There doesn't seem to be a review for them on here but there is one for the P67 version... Pentax 6x7 Reverse Adapter 49mm & 67mm reviews - Pentax Camera Accessory Review Database

Bob
08-05-2016, 01:44 PM   #21
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QuoteOriginally posted by Bob L Quote
The reverse adapter allows a lens to be installed onto the body backwards.
I looked it up on eBay and it looks like there is one for sale but I couldn't see the lugs for mounting into the camera body maybe I am missing something. But the price tag is substantial given the fact that I would still need to get the lens to go with it.
08-05-2016, 01:49 PM   #22
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QuoteOriginally posted by littledrawe Quote
This is probably the direction I'll go, I just need to spend some time figuring out which tube lengths will give me what amount of reduction of MFD.
Quick & dirty math: An extension tube of X millimeters on a lens of focal length of F millimeters will change the working distance of a lens set to infinity to a bit more than F*F/X.

And if you know the magnification you want -- the ratio of the sensor size to subject size -- then the amount of extension that will get you that is simply m*F.
08-05-2016, 03:12 PM   #23
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QuoteOriginally posted by littledrawe Quote
I looked it up on eBay and it looks like there is one for sale but I couldn't see the lugs for mounting into the camera body maybe I am missing something. But the price tag is substantial given the fact that I would still need to get the lens to go with it.
I didn't find it on Ebay but KEH have one for $53 https://www.keh.com/shop/pentax-645-reverse-adapter-645-58-719406.html

I paid a little more for mine but that's the norm here in Europe.

Bob

09-04-2016, 10:17 PM   #24
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I have the 120mm FA Macro. It is a great lens for macro work. I also purchased a set of extension tube. The extension tubes work well and give more flexibility. I primarily use them with a Hartblei 45mm T/S; with good results. I have not used the tubes with other / longer lenses or with the 120mm Macro. It I were starting from scratch, I would go with the extension tubes because of cost only. To reiterate, the 120mm Macro is a great lens; maybe the best 645 legacy lens. I use it all the time, macro and non-macro, and love it.
09-05-2016, 06:00 AM   #25
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You can also mount the reversed lens on extension tubes!
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