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10-17-2010, 08:05 PM   #31
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QuoteOriginally posted by newarts Quote
A Raynox 150 on your DA 77 will yield about 1.56x at a working distance of about 208mm.

A Raynox 250 on your DA 77 will yield about 1.84x at a working distance of about 125mm.

I recommend trying the $50 Raynox 150: a modest enlargement of 28% will give excellent image quality at the 1:1 magnification you seek. All the automatic functions of your lens will continue to work including p-ttl flash. The working distance will be a little more than the 200mm for a 100mm macro lens at 1:1.

It will be as easy to use and challenge the image quality and ease of use of a fully automatic 100mm macro lens (except for autofocus which is of little use at these magnifications).

Dave

PS see the Raynox Macro Club on this forum for examples of image quality: https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/74221-raynox-macro-club.html
Dave,
Thanks for providing some hard numbers for the Raynox. I had done the calculations before, but could not find them or the "how-to" articles. Looking at your numbers and the Raynox images on this site, it is easy to see why they are so popular.

Steve

10-17-2010, 08:50 PM   #32
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QuoteOriginally posted by newarts Quote
I think Natural vignetting is basically why the registration distance for most all cameras is similar to the image plane diagonal (image plane diagonal=image circle diameter).
Except they aren't. From the Camera Mounts Sorted by Register webpage we get:

Leica M bayonet 27.95mm
Canon screw---- 28.8mm
Konica Hexar RF 28.00mm 0.03mm
Leica screw ------28.8mm
Contax G1 bayonet 29mm
Hasselblad Xpan 34.27mm, 0.03 mm
Contax RF ------- 34.85mm
Nikon rangefinder 34.85mm

These registers are all significantly less than the ~43mm diagonal for a FF/135 frame. I'm not sure about the Hassy, but AFAIK all the rest are FF/135 RF's. The 40-45mm registers are to provide clearance for SLR mirrors.
10-18-2010, 05:22 AM   #33
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QuoteOriginally posted by stevebrot Quote
Dave,
Thanks for providing some hard numbers for the Raynox. I had done the calculations before, but could not find them or the "how-to" articles. Looking at your numbers and the Raynox images on this site, it is easy to see why they are so popular.

Steve
Steve, I made a serious typo on the magnifications. They should read:

QuoteOriginally posted by newarts:
A Raynox 150 on your DA 77 will yield about 0.56x at a working distance of about 208mm.

A Raynox 250 on your DA 77 will yield about 0.84x at a working distance of about 125mm.
My statement that a modest enlargement is needed to get to an effective 1:1x was also wrong... for the DCR 150 case an enlargement of 1.78x will be needed - not "modest" but do-able.

Sorry,

Dave

PS On the matter of "natural vignetting" limiting image circle (or angle) a variety of means are used to compensate for it, including radially graded and filters in the lens. The links I gave discuss strategies.

QuoteOriginally posted by SteveBrot:
I own two large format camera lenses, a 90mm and a 150mm. The 90mm has an advertised image circle of 221mm (102 degrees) at f/22 and the 150mm has an advertised image circle of 231mm (75 degrees). ....
Those are very large illumination circles indeed; 9 inches! How large is this camera? How far are the lenses from the film plane when in use?

You are certainly correct about the egregious hijack of the thread. I apologize to all.

Last edited by newarts; 10-18-2010 at 07:43 AM.
10-18-2010, 05:32 AM   #34
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QuoteOriginally posted by newarts:
I think Natural vignetting is basically why the registration distance for most all cameras is similar to the image plane diagonal (image plane diagonal=image circle diameter).
QuoteOriginally posted by RioRico Quote
Except they aren't. From the Camera Mounts Sorted by Register webpage we get:

Leica M bayonet 27.95mm
Canon screw---- 28.8mm
Konica Hexar RF 28.00mm 0.03mm
Leica screw ------28.8mm
Contax G1 bayonet 29mm
Hasselblad Xpan 34.27mm, 0.03 mm
Contax RF ------- 34.85mm
Nikon rangefinder 34.85mm

These registers are all significantly less than the ~43mm diagonal for a FF/135 frame. I'm not sure about the Hassy, but AFAIK all the rest are FF/135 RF's. The 40-45mm registers are to provide clearance for SLR mirrors.
You are correct. This is the second time I have jumped erroneously to the registry distance- image circle conclusion! Darn!

Sorry,
Dave


Last edited by newarts; 10-18-2010 at 05:56 AM.
10-18-2010, 05:57 AM   #35
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One option I haven't seen here, and I have the same Sigma 50mm macro, is to stack it on top of a decent quality converter like the Kenko 1.4x Pz-AF which we have seen being sold on the markerplace around here quite regularly. (actually, I got mine here as well)

This gives you a 70mm with quite a bit of play with closest focussing distance at that, without losing flexibility and a negligible hit on IQ while retaining all of the automatic functionality of the camera.

Examples:


10-18-2010, 06:12 PM   #36
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QuoteOriginally posted by scathontiphat Quote
thanks so much guys. it's been a great help!! time to start trolling ebay for tele-primes, enlarger lenses and bellows

What's the image circle like on enlarger lenses? If i can find bellows with rise/fall or shift movements and use an enlarger lens how much can i move before running into the edge of the image circle?

thanks!!
I use bellows and enlarging lenses on a budget.

This is an article I started on the subject.

https://sites.google.com/site/inexpensivemacrophotography/

Camp fire with bellows and enlarging lens.

10-19-2010, 11:03 AM   #37
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A cheap alternative could be the Cosina 100mm 1:3.5 which does 1:2 on itself and 1:1 with the "matched adaptor" (a lens that goes to the filter thread, part of the original package). This has been sold under various brands (at least Cosina, Phoenix, Promaster), mine is a Promaster which I found on Ebay, for US$ 82 (MF, NIB). Working distance for 2:1 is the minimum focus distance, 43 cm, with the "matched adaptor" about 10 cm. [EDIT: There is one on ebay.uk (NIB with the adapter) currently going for 2.60: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=160492829683]

Another lens that springs to mind is the Tamron 70-300mm 1:4-5.6 which can do 1:2 macro with a generous working distance of 0.95m. This is quite cheap new, so I'd expect that a second hand one can be had for US$ 100.

Links,

Cosina:

Cosina AF 100mm f/3.5 macro (Pentax) - Review / Lab Test Report
Cosina 100mm F1:3,5 MC Makro Lens Reviews - Pentax Third-Party Lens Review Database
Phoenix 100mm f3.5 macro with 1:1 matched adapter Lens Reviews - Pentax Third-Party Lens Review Database

Tamron:

Tamron AF 70-300mm f/4-5.6 LD Di macro (Pentax K) - Review / Lab Test Report
Tamron AF 70-300mm F/4-5.6 Di LD MACRO 1:2 Lens Reviews - Pentax Third-Party Lens Review Database

Last edited by jolepp; 10-19-2010 at 01:42 PM. Reason: added Ebay plug
10-19-2010, 12:01 PM   #38
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stover, I can see why you would want some working distance! :-)

10-19-2010, 12:27 PM   #39
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Yet another option that hasn't come up in this thread is a Vivitar 2x Macro focusing TC, the PK-a/R-PK which allows for 'A' use (but manual focus which shouldn't matter with macro). It doubles your focal length and shortens the minimum focusing distance. For macro work it's been great for me and at ~$75 on eBay it was well worth it.

Under the SMC A 50 1.7:



Under the DA40:



Under the DA15:

10-19-2010, 12:36 PM   #40
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QuoteOriginally posted by Nick Siebers Quote
stover, I can see why you would want some working distance! :-)
I've mentioned before (but not yet in this thread) about putting a LONG tele (400mm+TC) on LONG extension (bellows+tubes) steadied with a shoulder mount (so it all looks like an RPG launcher) for shooting close-ups from a safe distance (like staying >3m from the rattlesnakes). Sometimes, distance is prudence, eh?
10-19-2010, 05:13 PM   #41
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QuoteOriginally posted by Nick Siebers Quote
stover, I can see why you would want some working distance! :-)
I am trying to remember the focal length - 105 or 135 (perhaps something below 105) for the fire photo.

To be fair, the fire was all but dead. This was a long exposure (10 to 15 seconds). Most of the coals were dark ash and I was able to isolate this small patch of embers.
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