[rmtagg]

rmtagg,

I'm a measly inch away or so at 1:1 magnification. That being said, if the subject can't run away, the dof really is worth the trade off in my opinion. The dof is thin, but nothing like some I've seen from longer focal length lenses. e.g. What do you mean you can't tell it's a flower? Look how sharp that point on the tip of the pistil is.

Matt

Matt, I love your orchid photos! Now what is a slider head? Sorry, I'm still pretty much a newbie

[aegisphan]

Usually I call it a macro slider. Here is an example of a double slider

Velbon Macro Slider

I use it mostly for 1:1, wide open shot of flower. At this magnification, the DOF is extremely thin, you use the slider for precise movement to get the specific part of the flower in focus. It's much more convenient than to move your whole camera+tripod setup back and forth. There are two type of sliders: a double slider (you can move in 4 directions) and a single slider (only back and forth). The double slider is more expensive.

I bought a double slider, but later converted it into a single slider to use as a paranomic head as well. So the left and right movement is not that important.

[loudbay]

Aegisphan, Do you have a shot with your Voigtlander (I'm looking into this lens for bug season) to demonstrate a difference between the 50mm DOF and the 125m DOF (working distance as well)? I would be happy to take another test shot at similar settings. May be interesting to see what we can see. Maybe a boring coin shot so we can both take similar pics.

rmtagg, thanks for the complement on the orchid shot. I took 7 at the green house that day, and 2 came out as keepers. The other decent one is not as sharp, probably just the fans in the greenhouse messing with my shot. Here is the other one: first resized, then a 100% crop at the point of focus (although far from perfect).

[aegisphan]

1:1 Wide Open (Very comfortable working distance)

70% Cropped and Original (No PP)





If you have both lens at the same magnification and aperture, the DOF will be the same since focal length has no impact on DOF. Most of time, peole associate the longer FL to have thinner DOF, but that's just simply because it has greater magnification. Good luck with the find, the Voigtlander is one tough beast to find. I think you might find the Sigma 180 to be better for bug shot (especially for those shy guys). I prefer the FA* 200 macro, though I hope Pentax would release a DA* macro version. That would be very nice.

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Last edited by aegisphan; 03-15-2008 at 10:34 AM. Reason: Original added

[loudbay]

If you have both lens at the same magnification and aperture, the DOF will be the same since focal length has no impact on DOF. Most of time, peole associate the longer FL to have thinner DOF, but that's just simply because it has greater magnification. Good luck with the find, the Voigtlander is one tough beast to find.

I could be wrong, but I think that is not a true statement. I found a DOF calculator on the web (VWDOF) and without going too deeply into specifics for our specific lenses, on the same sensor, a 50mm at f2.8 at 1 meter has a DOF of 63.9mm and a 125mm at f2.8 has a DOF of 9.41mm.

That's a HUGE difference. This could be changed by properties of a macro lens, but I think the math behind this is solid. We should both do some 1:1 coin shots at a 45 degree angle and see what they look like. I'll post one up as soon as my wife gets home with the truck (and tripod).

Matt

[loudbay]

Alright, I thought this through a bit more and to recalculate for our specific lenses I need the actual working distance. When I take the coin shot in a bit, I'll be sure to measure as well.

Can you get me an accurate working distance at 1:1 as well.

Now I'm just plain curious.

M

PS: your Voigtlander shots are AWESOME!!!!

[aegisphan]

At 1:1, the working distance is 38cm.

I could be wrong, but I think that is not a true statement. I found a DOF calculator on the web (VWDOF) and without going too deeply into specifics for our specific lenses, on the same sensor, a 50mm at f2.8 at 1 meter has a DOF of 63.9mm and a 125mm at f2.8 has a DOF of 9.41mm.
Matt

You misunderstood me. I said DOF only depends on the aperture and magnification. A 50mm lens at 1 meter and the 125mm lens at 1 meter would not have the same magnification. In this case the 125mm will have greater magnification; thus, the DOF of the 125mm will be much smaller.

The provided software only gives you a general idea of DOF. Since each macro lens does have different minimum working distance (due to the variation in the real focal length), this software would not give you an accurate result. I don't know if it even works with a real macro lens.

Hi,
I got a K10d last Aug and love it! I have a 70-210 5.6 macro lens from a 35 mm camera. I am getting older and can't seem to hold still as long now so I would like to get something a little faster. I don't have a lot of money to spend on a new lens so I thought I would ask for suggestions. This pic is an ex of what I typically use the lens for and I do need crisp sharp images. Any help is appreciated.

I thought I would add my 2cents... I just picked up a Vivitar Series 1 105 and I love this lens. It is an "A" lens so it has full functionality except AF, but as others mentioned MF on macros is really helpful anyway. The minimum working distance is about 5 inches so bug shots are at a decent distance away. I find it is also a wonderful 105mm prime lens for portrait work. Very sharp and fast.

I have seen them used from 175 to 225.... and worth every penny IMHO. You cant go wrong with this lens...
The tamron 90mm AF and sigma 105mm AF are also wonderful lenses if you want a newer lens, but they may be out of your initial price range.
And of course the Voigtlander 125 is the mother of all macros and the sigma 180 is back in stock again.... but that is some serious pocket change....

For 200 dollars though the Series 1 105 is a great option...

good luck








And a couple of portrait shots

[aegisphan]

Alright, I thought this through a bit more and to recalculate for our specific lenses I need the actual working distance. When I take the coin shot in a bit, I'll be sure to measure as well.

Can you get me an accurate working distance at 1:1 as well.

Now I'm just plain curious.

M

PS: your Voigtlander shots are AWESOME!!!!

Thank you for your kind words. By the way, I don't actually measure the real working distance. The 38cm is just based on the official spec. However, I will definitely do a coin shot, though I would want to know what kind of coin you are using to standardize the two shots.

[loudbay]

Let's use a U.S. dime. Focus point at the bottom of the torch on the 'tails' side of the coin. The details are the smallest here. If you have a better suggestion I'm open to that as well. I read a couple more web sites and you are for sure correct. The difference in DOF at macro distances is really just statistical difference. I think with the dime, it will be interesting to see the differnt field of view as well.

I saw you are selling your Vivitar 105mm. I also read your comparison post. I may look into the Vivitar instead of the Voigtlander just because of the cost difference, although you definitely made the right decision. Every Voigt shot I see is 'above par'. Do you think the quality difference is worth the price difference (if you were starting all over again)?

Cheers, Matt

[aegisphan]

For handheld shot of active insects, I always use at least f/4. At this aperture, the performance is nearly identical. Definitely at f/5.6, I couldn't even discern them from each other. However, being a non-APO lens, the Vivitar and many long FL macro lenses might render highly reflective, OOF surfaces (such as water droplets under harsh daylight and high magnification) not as desirable as the Voigtlander. But OOF rendering depends on personal taste so I can't say the same for you.

With that said, the Voigtlander is quite heavy so it might not be suitable for long hike/field work. I would definitely pick up my Tokina instead. In the end, if you do a lot of shots that are not wide open, then the Vivitar/Tokina would be my prime choice (weight, cost, and performance).

[loudbay]

Thanks for the input. I'd take that Vivitar off your hands, but I just go the 50-135, so I've got to wait until the bugs come out to justify it. I took the dime pics. now that I see them up close, my point of focus was just behind the bottom of the torch. For comparison purposes, I don't think that will make too much of a difference. My working distance was more like 2 inches from the front element to the focus point.

I shot at 1:1 in Av mode at f2.8 f4 f5.6 f8 f11. I used the mirror lockup on my k10d on a tripod. Resized to 800 pixels on the long edge in CS3 uploaded via pentaxforums.com (for comparison purposes).

Edit: I shot f16 and f22 as well, but really no point if we've determined that there's not going to be difference in DOF. Really no point in any more than 1 shot, but too late now.

[loudbay]

Rmtagg:

When you're looking around for macros now, you'll have more information for sure.

Working distance, 2 in or so with the 50mm at 1:1 magnification. Considerably more with a longer focal length lenses.

Field of View, The 50mm will include more of the subject's background, while the longer focal lengths will allow you to isolate your subject a bit easier. The difference should be apparent here when you get to see the dime with the longer Voigtlander 125mm.

As for depth of field between the two. At macro magnification, you shouldn't be able to tell.

Let me know if this discussion has led to more questions. It sure has for me.


Cheers, Matt

[rmtagg]

there is a Voigtlander on ebay right now!

[rmtagg]

I have to thank everyone for their suggestions, education and helpfullness! I am so glad I asked, I have learned so much already. I feel I have been craming info into my brain but everyone here has helped me make sense of it.