12-08-10 – Optimus Prime

Two straight out of the camera (and then scanned in), and one more to choose. probably from a bunch I took this Sunday with my fisheye (it’s a prime, right?)

And I can’t understand why Orionid would even want to crop a cat of the shot. Leaving it in would guarantee every vote in
the Caturday Thread caucus 😆

to further complicate the rules: what about lens reversal macro as one of the photos? (i.e., 2 shot normally, 1 with the same lens but reversed.)

[still undecided if i want to post 3 from the nifty-fifty or 3 from the 10mm…..]

I’m in the no crop camp. It’s too late to add to the difficulty but I will probably take cropping into consideration when voting. I always felt that part of the challenge of using a prime is that you have to compose more carefully to get the best effect from the lens.

This. I would like to say no crop, but how do you enforce it? Sure, obvious crops are obvious, but a subtle crop, chances are no one would know. I say let the voting do the thing, throwing it to the wild whimsy of Fark.

I’ve decided to go with the Darlot ‘macro’ for this, but I have a problem. I’m using it in conjunction with my 28-80mm Tamron lens. This lens, at 28 mm, is slightly extended. As you bring it ‘up’ it retracts to somewhere near 44-46mm, then extends back out as it approaches 80mm. Since the Darlot is merely held up to the Tamron lens, I find its a bit easier to manage if I use it to ‘push’ back the Tamron to it’s fully retracted position. That gives a nice vignetting around the edges of the frame. Problem being that it’s an inexact science, and I have pictures registering from 42mm to 46mm. I’m going with three at 46mm, though I’d like to use one at 42 as I like it better. But prime is prime. I’ll live.

Next issue, anyone know how I can figure out what the effective magnification is? I’m not sure it’s even not 46mm, just that I can be inches from the subject rather than 2.5 feet. It’s a petzval lens, if that’s any help. Here’s a shot (which happened to register at 43mm) though the same gettup as for the contest to give an idea of scale. The front optic of the Darlot is about 3 inches from the ruler here.

sleeping‘s response about reverse mounted lenses above suggests that putting one lens in front of the other like you describe no longer qualifies as a prime lens.

While it’s true that it’s not a prime, if all 3 shots were done the same way at the same focal length, that still qualifies, though, yes? I would think that’s the same as what us non-prime owners are doing – shooting 3 at the same focal length.

But it’s also in front of a zoom lens that slides around between 42 and 46mm. That’s not exactly set at a single focal length as the theme requires..

I’ve got 3 (usable shots) where the EXIF data tells me they are all at 46mm (I can only presume the camera itself knows it’s focal length). Given the Darlot cannot be changed, then whatever the combo focal length is, it should be equal between the three. The Darlot, for what it’s worth, is not reversed in any of the three, which would affect the ratios due to where the lenses sit within the Darlot lens body itself (extensioning). I’m working with the equipment I have, not the equipment I wish I’d have.

It’s pretty evident (to me) in the shots that they are all within spec, of equal focal length. But hey, I’m just an end-user. Here’s a link to the three I plan using. Your call. It’s either these, or I’ll sit this one out, as I don’t have time at this point to get viable alternatives.

I’d rather not post at all than pick three alt’s taken though the telescope that, while guaranteed ‘prime’, don’t come close to the Hubble-quality that people expect from astrophotography and wouldn’t get squat for votes.

As it is I don’t think my shots are going to fair well, so if I have to sit it out for lack of equipment, so be it.

http://fossilspringsaz.com/pics/2010/dec/08/check.html

(going with an animal/vegetable/mineral theme, obviously)