Blurryeyed Loc: NC Mountains.

Since my 100mm lens died I have been spending a lot more time shooting reversed lens and have noted that sometimes I struggle with some really soft images and other times not. As best as I can figure out this is caused by improper exposure as well as flare usually caused by the quality of the background and how the flash interacts with that. I am posting two pics shot with the same setup and the same lens and shutter settings.... but the pic taken of the black fly in the grass is much more acceptable to me than the one of the fly dead on... In fact, the one of the fly dead on is pretty much unacceptable because it is so soft. I am thinking that the softness is caused by the background being light in color and reflective in its properties causing a bunch of light to flood the lens creating flare that softens the entire image, the background of the other pic does not create this problem nearly to the same extent.

I see this not only in my own photography but I also feel that I see it in pics posted by others especially when using extension tubes....

These are just my thoughts but if you are experiencing similar issues and don't understand why some images are sharp and others not... it is something that you may want to consider and try to manage.

martinfisherphoto Loc: Lake Placid Florida

I agree and think it's either Light or Flash coming back down the tubes. I notice it more when shooting against a solid background. The spider was on a Sun Lit Wall. Here's an example with 56mm tubes and the 100mm macro lens.

LoneRangeFinder Loc: Left field

I've had some trouble-- not so much with flare, but with DOF, which I naturally assumed to be a natural property of the already shallow DOF, compounded by adding the tubes. I'd like to see some similarly posed subjects with the only difference the background. In fact, the two examples are different: one is head on and the other a side view. Would not the head-on view create a bigger DOF challenge? Perhaps an illusion? Or are the tubes leaking light? Have you wrapped the tubes to eliminate this possibility? I guess my question would be: would not the same outcome occur (reflective flare from a light background) with a macro lens only?

Anyway, just thinking out loud... I need to go test this.

Blurryeyed Loc: NC Mountains.

I have some velcro material inside the tubes that seems to help a little, the setup I am using is even worse than a regular lens mounted on tubes because I am using the back element of a 28mm lens as the front lens on this setup. The lens is very small and has a good bit of curvature which I think compounds the problem of flare, even though I have fashioned a small hood for it.

What I have noticed is that in some conditions I get excellent results... in other conditions I get really poor results, an example of this is the bee shot that I am attaching, if you download it and take a good look at the beak you can see that the lens is capable of producing high quality resolution under the right circumstances. This setup is about 3X mag and I shoot usually at f/11 because I just can't see to focus very well at smaller apertures so the DOF is very shallow. But the area in focus is pretty sharp in this pic which is the case about 1/2 the time, the other half the time it looks like the lens is incapable of sharp focus and I think that is mostly caused by flare... I think that in really bad cases flare shows up very noticeably as it does fstop's spider pic, kinda a milky whiteness to that pic and low contrast, other times as in my fly pic I think it shows up as just poor focus, maybe it is refraction even though at f11 refraction should not be a huge issue...

These too are just my thoughts, that is the value of this forum, when we discuss some of the problems we are having we not only help others struggling with the same problems, sometimes we figure it out, or even better yet sometimes someone comes along that has more experience and coaches us through the problem.

martinfisherphoto Loc: Lake Placid Florida

One observation I can make is the hugh difference between Reverse stack and reverse on tubes. Reverse stack the photos mostly turn out better than your viewing as the shutter closes down and you tend to get a better shot. Just get close and you have a sharp photo. DOF seems to be a little better also. With 56mm of tubes to a full set, to lock on focus is much more difficult. If I breath I loose focus. I have upped my shutter speed to 1/320 and that seems to help. I'm still less than 50% with my tubes, but I'm also working at MWD at all times. When you pull back the % goes up. When I nail focus it's there, when I don't well I just keep plugging along. I wonder if some of these shots you are just missing that Narrow Focus Window. At F/11 the window would only be Paper Thin and your not using a tripod..

This is the same shot cleaned up

Blurryeyed Loc: NC Mountains.

I had about 15 shots of that fly and they were all pretty much the same, I had the lens hood on the hard surface that the fly was on so the camera was not only steady but I had the ability and time to work on good focus... I really think that it was a combination of solid background compounded by the fact that the background was very light in color... the flash burst I am sure is bouncing off the surface causing a great deal of the problem, with the bee and the fly in the grass the flash is was not bounced back so hard.... that is my theory anyway.

LoneRangeFinder Loc: Left field

I think your situation is different than macro alone vs macro + tubes, given the type of lens you are reversing. What I cannot see is that flare would increase with simply adding the tubes to the equation.

Blurryeyed Loc: NC Mountains.

I see flare in both Tinsbum's and fstop22's shots, not always but I do see it... if you do a google search on flare and tubes you will see it discussed on various forums.

martinfisherphoto Loc: Lake Placid Florida

I did try to shoot a crane fly the same day, with my lens braced and missed at least 10 tries.. I thought it was me and just walked away. I swore I have the bug dead on but could not pull the shot off. I Could Not get the Eye. Maybe you have a good point.

martinfisherphoto Loc: Lake Placid Florida

I never get flare with just the macro lens. The more tubes I add the more flare I get. But it also depends on the shooting conditions. Not every shot but with High light the flare increases.

LoneRangeFinder Loc: Left field

I'll accept this based on your greater experience.

The reason it doesn't make sense to me is that the angle of reflected light with extension tubes is less than the same lens without. This is because the distance from sensor to the lens element is greater with the tubes.

evobob Loc: San Diego USA

I agree also!
going to check it out

Blurryeyed Loc: NC Mountains.

I actually think that it is caused by the construction of the tubes, it is my understanding that it is not so much of a problem with a bellows. The light bounces around in tubes but the cloth like construction of the walls of the bellows is non reflective. Even though the tubes are painted black, they still reflect light.

LoneRangeFinder Loc: Left field

Makes sense.

evobob Loc: San Diego USA

sounds good, telescopes(good ones)(refracters) have baffles in them to stop reflections