Macro Gear

[PWhite214]

I recently received a Minolta 100mm bellows lens with a bellows that extends the lens out to approximately 150mm. A bellows lens has no focusing mechanism, it is designed to be mounted on a bellows unit for focusing. With the aid of a macro (no glass) adapter the Minolta MC series equipment fits on the Sony Alpha camera body. This bellows was modified specifically for medical photography, with the addition of a flash bracket mounted on the lens. The bracket rotates around the lens axis.






I mounted a Vivitar 285HV flash on the bracket instead of the original flash supplied with the kit. The 285HV has an adjustable output, 1/2, 1/4, 1/16, so it is easier to get the correct exposure. A dedicated Sony flash would be the best, but I do not own one (yet).

The results






I am very pleased with the kit and results. A new flash bracket is on order, and will be modified to fit the bellows. The flash will not be touching the bellows, and adjustments will allow various flash angles. I will be searching for more subjects, while waiting for spring and the insects.

Phil

[abchip]

Nice setup! It definitely produces great results. Am I right to assume that you would always use this setup on a tripod? Could you explain again how it focuses if it dosen't have a focusing mechanism?

[PWhite214]

Actually, I have tried to use a tripod, but not sucessfully. I put the bellows on the tripod for the photos of the gear. The flower shots are hand held, I was lieing on the ground with the lens about 3" from the flower.

For focus, set the extension then move the whole camera untill the subject is in focus. Use the same method with extension tubes.

These photos were shot at f32, 1/125 Sec with the flash, ISO 100

Phil

[abchip]

Thanks for the explanation! You do great work using the bellows. Hopefully you'll find more subjects and don't have to wait till spring.

[daft_biker]

Originally Posted by PWhite214

These photos were shot at f32, 1/125 Sec with the flash, ISO 100

I'd try to avoid f/32 as the physical aperture, especially when using a lot of extension, as the effective aperture will be much smaller and you'll get soft images due to diffraction effects. Even at the small size shown the 2nd shot looks a bit soft.

Knowing the exposure factor for a shot would let you work out the effective aperture from the known physical aperture that you set. Normally I think it's:
Exposure factor = (1 + Image magnification ratio)²

Multiply the physical aperture by the exposure factor and you get the effective aperture. Amazing how quickly the f/numbers go up isn't it!

If using flash to light the shot (available light isn't likely to do much with those settings) I'd normally just go for the highest flash sync speed. With the A200 I think you're pretty much there as I think it only does 1/160th but other DSLRs usually have even faster sync speeds - up to 1/500th on some I think.

Looks like a cracking setup anyway.....could have loads of fun with that I'm sure