IR vs. Rolleinar

[Toffle]

I'll post this here, but it may probably be better suited to one of the other threads.

I printed a bunch of contact sheets last night. (is anyone else as far behind as I am?)

My first roll of SFX has some really good shots, a couple of near misses and some "what the Hell???" Focus is generally good, but apparently SFX is not very compatible with my Rolleinar. (I'm using a Rolleiflex 3.5f) Makes sense... the closer you are, the more critical the focus... IR focuses on a different focal plane, so you pretty much have to know what you're doing. I don't.

I know that many SLR lenses have an IR focusing mark, but I don't know if that is the issue here. As I said most of the shots were well focused; it's just the couple that I did with the Rolleinar that are off. Any hints?

BTW, I was shooting with a Rolleinar 2, if that makes any difference.

Cheers,

 

[Marco Buonocore]

Hi Tom,

Did you have the rolleinar on correctly? The 'fat' lens goes on the viewing lens - red dot up, the 'thin' lens on the taking lens.

If you did, then I expect you're right about critical focus - you lose your safety net of DOF when you're doing close up work. I don't recall seeing a lot of macro IR work, probably for that very reason.

 

[Toffle]

Yup... red dot up. I have seen some IR macro somewhere recently. I suspect it is something that requires some practice. It is worth a few experiments, I think.

Thanks.
Cheers,

 

[Nicholas Lindan]

My first roll of SFX ... Focus ... not very compatible with my Rolleinar.

You may have to experiment. The IR focus correction isn't the same on all lenses and the Rolleinar more than likely changes any near-IR chromatic correction.

Set a ruler at a 45 degree angle to the lens, the lens wide open, your normal IR filter in place, the focus knob set to 7ft (the middle of the focusing range) and then move the camera so the 6" mark is in focus and take a picture. If, as an example, the print shows 7" as the center of focus then note the focus knob change needed to move the focus point from 7" on the ruler to 6" on the ruler.

Applying this same change should work 'good-enough' over the focusing knob range, but you may want to do the experiment with the knob set at infinity and 3.5ft just to make sure.

Like most things, you may need a final tweak to the determined correction.

 

[ntenny]

My first roll of SFX has some really good shots, a couple of near misses and some "what the Hell???" Focus is generally good, but apparently SFX is not very compatible with my Rolleinar. (I'm using a Rolleiflex 3.5f) Makes sense... the closer you are, the more critical the focus... IR focuses on a different focal plane, so you pretty much have to know what you're doing. I don't.

That was pretty much my experience. Near-IR doesn't require much of a focus shift, but at really close range maybe it becomes significant. The only shots I ever took with IR film (Maco 820c, which reaches deeper into the IR spectrum than SFX, but nowhere remotely close to HIE) and a Rolleinar looked like mush.

Presumably someone with enough skill and experience could get them to work together, but I'm kinda lazy and I just wrote it off as "these things do not work and play well together".

-NT

 

[Toffle]

That was pretty much my experience. Near-IR doesn't require much of a focus shift, but at really close range maybe it becomes significant. The only shots I ever took with IR film (Maco 820c, which reaches deeper into the IR spectrum than SFX, but nowhere remotely close to HIE) and a Rolleinar looked like mush.

Presumably someone with enough skill and experience could get them to work together, but I'm kinda lazy and I just wrote it off as "these things do not work and play well together".

-NT

Thanks for the voice of experience. It is more or less what I expected. I do have a few rolls of Maco in the fridge that I won't waste on my Rolleinar. There's so much more out there to shoot anyway. (I've also got two rolls of HIE in 35mm that I'm saving for a runny day.)

Still, if you don't try things, you never know what will work.

Cheers,

 

[JPD]

Do you use the Rollei Infrarot filter? It's not only a filter, but also a weak lens that corrects the focus for IR-light. I don't know how well it works with Rolleinars though.

 

[Toffle]

Do you use the Rollei Infrarot filter? It's not only a filter, but also a weak lens that corrects the focus for IR-light. I don't know how well it works with Rolleinars though.

I did not know this. That could be very handy compared to my current system. I've been using the very precise and scientific method of holding the filter in front of the taking lens.

Thanks for the tip.

Cheers,