newbie questions on macro focus stacking with Nikon camera

[albert]

I bought a 50mm f/2.8 enlarging lens to try on the PB-6bellows.
The small booklet that came w/the lens says:
You can use the optional 40.5mm reversing adapters to mount the lens in the reverse position.

Does reversing the lens give greater magnification
or simply enable a regular lens to focus at a closer distance?
I have to experiment but hope to buy the right adapters.

The threaded part is 39mm and I am not sure if I need a reversal ring adapter or simply a 39mm threaded adapter to put it on the pb-6.
I imagine for macro it must be reversed, or why even bother with these old el-nikkor lenses.

I finally got the exposure much better
I had problems with the bellows, but will be trying again,
the problem was the intensity of the flash -I have to try the different Commander settings on the d70s.
On the bellows I was thinking of using a flash meter w/a manual focus lens
(such as the enlarger lens or others Ih ave from my film equipment), in later trials.

My first attempt had pretty dismal results. I used a nikon d70s, with R1 slave flash units, and a 105mm f/2.8 nikon af lens. The alignment came out terrible, right now I only have a mac os x so I used Helicon Focus. Is there some way to align prior to, or after stacking? I thought I was so careful but the movement was very evident in the extra antennae that showed up in the shots.

This was my basic set-up during this attempt:
I am using a proxxon drilling table to move the insect, taking about 60 shots for a complete travel distance of about 3mm
The camera is on a tripod and the shutter was released with remote control

I also have a Novoflex focusing rail but decided to experiment with this (moving the subject) method first. (Seems easier as my tripod is not the best.

Any suggestions are most welcome.

soon I will have a new (much faster:) windows xp PC
(I stayed away from vista) and will use that operating system because of it's greater choices in focus stacking software, so any software suggestions can also be made for Windows.

best,
ALbert

[lauriek]

thought I was so careful but the movement was very evident in the extra antennae that showed up in the shots.

This bit makes me wonder - was it just the antennae that had a problem? If so you probably suffered drooping antennae syndrome, don't worry we've all experienced this, it's slightly embarrassing but it happens!

This is just the effect of the antennae moving as the insect warms up/dries out. It's better to leave the specimen at room temperature for a while, for condensation to clear and for this problem to go away. But I tend to be too impatient to get stacking!

Personally I haven't got round to buying Helicon (yet - I'm sure I will eventually!) - I use either CombineZP which is free, and does alignment and stacking, and I also use Tufuse pro, which is a reasonably cheap stacking option, but it doesn't do alignment - I always use CZP to do the alignment for now..

With the lens thing, for non macro lenses it's normally better to reverse them when using on extension, though I'm not sure if this applies to enlarger lenses, I suspect so but wait for someone else to chip in on that!!

[rjlittlefield]

The alignment came out terrible, right now I only have a mac os x so I used Helicon Focus. Is there some way to align prior to, or after stacking? I thought I was so careful but the movement was very evident in the extra antennae that showed up in the shots.

Helicon Focus includes an "Autoadjustment" capability that is turned on by default and is normally able to properly align frames. Check under View | Preferences (at least that's the place on a PC), and be sure that Autoadjustment is enabled.

But from your description about how the shots were taken, I agree with lauriek that "drooping antennae" is a likely cause.

The proxxon table is very precise, most likely better for this purpose than the Novoflex rail.

One way to get a better impression of what is going wrong, is to play the stack as if it were a movie. On my Windows PC, QuickTime Player (Pro) will do this job. Just do Open Image Sequence, wait a while for images to load, set View | Fit to Screen, then grab the time slider and fly it around with the mouse. I assume it will work the same way on a Mac.

Does reversing the lens give greater magnification or simply enable a regular lens to focus at a closer distance?

Typically both. But the most important effect is to improve the image quality, by putting the short distance (to subject) at what would ordinarily be the rear of the lens, to match how the lens was designed.

Hope this helps...

--Rik

[DaveW]

Hi Albert,

The 50mm EL Nikkor f2.8 has a 39mm male thread for using in the conventional manner but a 40.5mm filter thread if you wish to reverse it.

Reversing the EL Nikkor on bellows. You need the Nikon BR-2A reversal ring (or similar independents one) that has a 52mm thread and a 40.5mm - 52mm STEP UP RING, yes a step up ring to step down! When reversing a lens you have to reverse your thinking since you are stepping up from the lenses 40.5mm filter thread to the 52mm thread of the reversing ring.

If you used a step down ring in these sizes you would have male and female threads the wrong way around for your purpose since the stepping ring needs a 40.5mm male thread to go into the lenses female filter thread and a female 52mm female thread to go onto the BR-2A's male thread.

Kood do such a step up ring:-

http://www.keene.co.uk/electronics/mult ... code=40552

Or Google around for a local supplier.

I know Nikon did do an enlarger reversal ring, but I dont know if it was just to a different enlarger thread rather than to Nikon bayonet for bellows mounting.

If you want to use the EL Nikkor the normal way around you will need a coupling ring having two female threads 39mm one side and 52mm on the other to fix to the reversing ring. Or construct something similar from standard coupling rings and step up/step down rings.

DaveW

[albert]

Thanks so much for your informative replies! - it helps.
I probably have all the equipment I need. and just need to work on my lighting and insect moving.
That first attempt just looked really bad..
The lighting is another issue, it also looked very flat, I tried to shoot it almost head on..

I am trying another round today.
I felt terrible killing this big honeybee,,
(roaches and flies in my apt, no big problem, but any other insect arouses real pity. Though I did freeze the bee, and he came out with his legs tucked in, I was hoping to find a painless method that would not distort the animal's appearance.
Ill will use this same bee until I perfect my skills :

best regards, albert

re the proxxon stage, I need to re attach it another way.
I just noticed there is quite a bit of 'play' (movement) on that top stage, what I was using, so even thought it is accurate it is not very stable

It is probably what caused my problem ( as the insect had been well thawed by the time I shot) The proxxon stage (KT 70) has both x & y axis, I set it up to use the top level but now see that it rocks slightly, quite abit actually. As the base level gets attached to the table it has no play. I guess that's the way to go

[albert]

my first attempt. a bit better but still
no details or real texture.

im off to the Jamaica Bay wildlife preserve (Queens, NY) to see what I can find. (in nature)
lll practice again with him later.

(looks gruesome impaled like that!