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05-13-2010, 09:03 PM   #46
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QuoteOriginally posted by yeatzee Quote
Any more suggestions? I was thinking there has to be an answer with reversing lenses minus the sigma 105mm... How much mag. will a reversed 28mm give me? How can I get 2:1 with a reversed lens with more working distance than less than an inch like my current setup?
A reverse 28mm lens gives about 2:1. I used the M 28/3.5 with a 52mm reversing K mount adapter, and a step ring to go to the 49mm front threads, and it came pretty close to 2.1X. The caveat is that you are still going to be very close to the subject. The lens to subject distance is very short: 45.46mm to be exact - the mount register distance. I only used it for still fixed objects. Bugs are another question entirely. If you use a 2X converter on a 1:1 macro, you get 2X on sensor/film.

I'm going to try some 170mm semi-auto-focus with my M100/4 macro later, when we warm up enough to have some bugs here, and just see what kind of quality I get. The aperture is going to make it hard to focus 4*1.7 = f/6.8 which is not exactly superb for manual focusing. Given sufficient contrast and light, it might work as a catch-in-focus with the F 1.7X AF. The M100 only gets in to 1:2 without help. My other alternative is to mount my 50mm extension tube on it, but I will still have aperture problems. That combo gives me a range of 1:2 through 1:1.


Last edited by Canada_Rockies; 05-13-2010 at 09:41 PM. Reason: Fixed typo: M 28/3.5 not M 25/3.5!!!!!
05-13-2010, 09:24 PM   #47
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The problem with teleconverters is they impact IQ which can be terrible on a macro image. The TC for the Tamron adaptall 90mm are flat field.
05-13-2010, 09:40 PM   #48
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QuoteOriginally posted by Blue Quote
The problem with teleconverters is they impact IQ which can be terrible on a macro image. The TC for the Tamron adaptall 90mm are flat field.
The specific converter I will be testing is the Pentax F 1.7X AF converter. So far it has exceeded my expectations, particularly with my DA* 50-135. It seems to work with the M 400/5.6 as well, but of course it multiplies the CA by 1.7X the pixels as well. I will try it on the M 100/4 macro just to see what it does. It may, as you suggest, destroy the superb IQ of that old lens, but one never knows! I might hit it lucky.
05-14-2010, 01:59 AM   #49
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QuoteOriginally posted by Blue Quote
Douglas, I didn't know Soligor made an AF 1.7x teleconverter.
Who makes it I don't know, but it is sold as Soligor. Works well (screw drive AF, no SDM). Not that much degradation on a good lens. Small. Probably an 4 lens solution. They also sell a 7 lens 2x converter.

05-14-2010, 05:54 AM   #50
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QuoteOriginally posted by Canada_Rockies Quote
The specific converter I will be testing is the Pentax F 1.7X AF converter. So far it has exceeded my expectations, particularly with my DA* 50-135. It seems to work with the M 400/5.6 as well, but of course it multiplies the CA by 1.7X the pixels as well. I will try it on the M 100/4 macro just to see what it does. It may, as you suggest, destroy the superb IQ of that old lens, but one never knows! I might hit it lucky.
I was referring to the average TC out there. Your F is one of the best one optically for tele lenses, but haven't sen how it does for macro use.

QuoteOriginally posted by Douglas_of_Sweden Quote
Who makes it I don't know, but it is sold as Soligor. Works well (screw drive AF, no SDM). Not that much degradation on a good lens. Small. Probably an 4 lens solution. They also sell a 7 lens 2x converter.
I wonder if its the same people that made the Promaster 1.7x.
05-14-2010, 06:44 AM   #51
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Bellows - Enlarging Lens

You can get above 1:1 with a bellows and an enlarging lens below 135mm. The lens and bellows will run around $100.

If you want to skip a tirpod then get inexpensive tubes and put the enlarging lens on that.

Here is an article on the subject.

This water drop photo was not cropped and is over 3:1 Taken with a 50mm on a bellows - bellows fully extended. The white box is a flash.

05-14-2010, 08:31 AM   #52
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My main thing is working distance.... so whats the max. working distance with bellows @ 2:1
05-14-2010, 08:47 AM   #53
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QuoteOriginally posted by yeatzee Quote
My main thing is working distance.... so whats the max. working distance with bellows @ 2:1
It will vary with bellows extension and lens choice. However, it will be very close. A bellows is essentially an adjustable extension tube.

05-14-2010, 08:50 AM   #54
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QuoteOriginally posted by yeatzee Quote
My main thing is working distance.... so whats the max. working distance with bellows @ 2:1
It depends on the lens and if it's reversed.

If you used your M50/1.7 reversed on a Bellows @ 2:1 magnification (Bellows extension 80mm), your film plane to subject distance would be 230mm.

Phil.
05-14-2010, 08:56 AM   #55
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Right , so im asking what would be the best setup w/ bellows to achieve the most working distance while reaching 2:1....
05-14-2010, 08:56 AM   #56
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Bellows Length and Focal Length Determine Working Distance

Yup,
In general, the more you extend the bellows the lower the working distance, but the greater the magnification.

In general, the longer the focal length of a lens the greater the working distance, but the lower the magnification.

So there are a few variables to work with which is why I enjoy working with bellows and enlarging lenses.

Enlarging lenses are inexpensive allowing me to have a range of focal lengths. The bellows I own allow for the camera body to be moved closer or farther away from the subject in addition to adjusting the bellows (think of it as a focusing rack).
05-14-2010, 08:57 AM   #57
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QuoteOriginally posted by yeatzee Quote
My main thing is working distance.... so whats the max. working distance with bellows @ 2:1
The working distance cannot be calculated. It depends entirely on where the lens designer put the node, the point that is where a simple lens would be placed to get the same focal length. If the designer has put the lens node outside the lens to the front, you get more working distance.

Ignore the long winded explanation below if you so desire. Also, all figures are rounded in the below discussion. Don't get hung up on decimal values.

A 400mm lens, such as my M 400/5.6, has a node that is 400mm from the sensor/film plane. It is a telephoto lens*, not a simple long focus lens, so the node is actually outside the lens toward the subject. My ruler tells me that my lens is 11 3/8" from mount to front surface of the front element, or 289mm. to that I add the mount register distance of 45.46mm and get about 335mm. The node of my M 400 is some 65mm in front of the lens when it is focused to infinity.

A macro lens, such as a 100mm lens, most often has the node outside the lens toward the subject. A really good lens designer will move the node quite a bit toward the subject to give more working distance than he/she would need to provide on a 100mm lens that is not designed to work at extremely close distances.

*Telephoto lens: A lens that has an optical design that puts the lens node outside the lens toward the subject. A telephoto lens is a long focus lens; not all long focus lenses are telephotos. What used to be called "girl watcher specials" are not telephoto design, and may have as few as two elements. These are very long, skinny looking lenses when you see them on eBay.
05-14-2010, 09:00 AM   #58
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Alright, ha man this is getting complicated.

Ok so a question, how much working distance do cannonites have with the MPE-65 @ 2:1?
05-14-2010, 09:04 AM   #59
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QuoteOriginally posted by yeatzee Quote
Alright, ha man this is getting complicated.

Ok so a question, how much working distance do cannonites have with the MPE-65 @ 2:1?
Have a look here: Canon MP-E 65mm 1-5x Macro Lens Review
05-14-2010, 09:09 AM   #60
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So about 2.5 inches at 2:1..... Thats double what Im getting
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