Need for 180~210mm MC lens for close-up work

[redu]

Yes Bob, I guess coins will glitter at the end of the day.

[turtle]

Ok, that makes sense, but why is this a show stopper - incredible files are still possible are they not?

The 150 Apo Ronar MC would likely be within budget and should cover whatever sensor you are using. It might not be 180-210, but it is close. At this stage it seems there are no other options.

What are you doing that requires you to work exactly in this range of focal lengths and not tweak your digital files?

Dan Hi, It is best noticed on the histogram. When i shoot with a MC lens such as a Macro Symmar the whole available dynamic range of the scanback (even beyond it's capacity) is used. At correct exposure the whole histogram axis is full of information. However when i shoot i.e. with a G Claron for instance, regardless how good i expose, the information is more concentrated in the mid values and almost nothing shows at the far ends of the histogram (extreme blacks and whites) This i can of course correct at photoshop but thats just rearranging of the available limited data.

[redu]

I just would like to do the work properly.

Anyways.. Just came accross with this one in the unspeakable auction site. Well it seems like a little bit beaten but still a bargain as mentioned. Unfortunatelly the guy refuses to sell to places other than the USA. My bad luck. But if any of you guys living in the US are interested in playing with it a little bit and selling it to me later please go for it. Or.. go for it in any case.

[Lynn Jones]

As usual, Bob S. always makes good sense and he is up to modern knowledge base since he is still working in the field.

But Redo, your observations on optics I tend to disagree with mostly. With lenses of 60 degrees or less of equal lens quality, you should not be able to see any contrast or resolution differences between single or multi coating. Up to 80 or so degrees most observers won't see any difference, although scientifically there might be slight differences. The real differences come from super wide lenses (over 85 degrees), and the reason is that they cover so much area that direct sun or hot speculars will cause reflection problems and multi-coating really does make a huge difference. However, in at least one highly prized group of wide field optics, the most modern design with all the bells and whistles, all air spaced, multi-coating, modern computer design but, lots of the customers were not happy. The angle of view was reduced by quite a bit, and the contrast was reduced. Since I was associated with them, I won't name them.

You suggested that some enlarging lenses were uncoated, that would be older than you are. The last American enlarging lens to be uncoated would be in the early 30's, all of the German, French, and British lenses were coated by 1937 in my recollection.

Regarding enlarging lenses as taking lenses, they work well as long as you understand that the light angles are reversed in photography and when you approach 1:1 the lens needs to be reversed (as long since recommended by optical physicists).

Lynn

[Bob Salomon]

There are several differences. The first is that a process lens is optimized to only perform to specification at f22 for lenses up to 600mm. The second is that it is designed for flat art objects and do not reproduce 3 dimensional objects as pleasing as a macro lens like the Apo Macro Sironar do. Especially when you have objects near the edges as well as the center of the field.

So yes, incrdible images are possible with an Apo Ronar for macro but much better ones are possible with a macro lens and, if you are doing digital, even better files will be available from the Apo Macro Sironar Digital then from either the Apo Macro or the Apo Ronar.

But a major componant of quality is the user and what the user ants in quality and accepts for quality so while a major art director might throw a shot whose qualit you are happy with that doesn't mean that it is not a high quality shot. It just doesn't meet the ADs standards.

[redu]

With lenses of 60 degrees or less of equal lens quality, you should not be able to see any contrast or resolution differences between single or multi coating. Up to 80 or so degrees most observers won't see any difference, although scientifically there might be slight differences. The real differences come from super wide lenses (over 85 degrees), and the reason is that they cover so much area that direct sun or hot speculars will cause reflection problems and multi-coating really does make a huge difference. However, in at least one highly prized group of wide field optics, the most modern design with all the bells and whistles, all air spaced, multi-coating, modern computer design but, lots of the customers were not happy. The angle of view was reduced by quite a bit, and the contrast was reduced. Since I was associated with them, I won't name them.

Thanks for expressing your thoughts on this topic Lynn. I was a little unclear and i am sure you will agree with me when you learn my conditions. Well as i have mentioned up there somewhere, for table top product works, i am using a scanback to record the image. A Phase One Powerphase. At full resolution (8400x6000), I have two sensitivity choices 400ASA or 200ASA. They are both OK but 200 ASA produces some noticable difference, especially at the darks by means of increasing the detail and reducing the noise. OK, of course 200ASA takes twice the exposure time and we are talking ~25 minutes here. By nature these devices require a lot of light, especially at f16~f22 if you don't want to go for 40+ minutes exposures the only other option is to pump up the light. I have in total 4KW equivalent of fleurescent 5.6K lighting to make my neighbors wonder like "what the hell is going on in that room..?"

To cut long story short. MC makes real difference in my case and i have clearly noticed it on the histograms. Besides; as you may already know, MC is not only for the stray light entering to the optical system from outer space but also to reduce the inner reflections among the elements of the lens. So i guess, being ultra wide shouldn't be the only reason to multicoat the lens elements. If that was what you have meant.

You suggested that some enlarging lenses were uncoated, that would be older than you are. The last American enlarging lens to be uncoated would be in the early 30's, all of the German, French, and British lenses were coated by 1937 in my recollection.

Actually i don't know any MC enlarging lens other than the EL Nikkor series and Rodagon G. Rodagon G, that i've read somewhere, is optimized for 1:30 or so. I believe Nikkor EL 210 is a candidate for this job. I calculated it's coverage to be somewhere around 60~65 degrees. Does anybody here used an EL Nikkor for a similar application?

[Bob Salomon]

"Actually i don't know any MC enlarging lens other than the EL Nikkor series and Rodagon G."

The G was not multi=coated. The Apo Rodagon-N series is multi-coated.

[redu]

Thanks for the correction Bob.