Infinity objective on low-end zoom telephoto works fine

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Blame
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Post by Blame »

marisano

135mm is a decent choice of length and we played with a fair number of old camera lenses. It is very difficult to guess which ones will be best but the physically smaller do seem better. I think multi-coating is worth having so check it says something like MC.

You will probably get a little vignetting but there is a very good chance it will be decent. However in my experience a 135mm enlarger lens is a safer bet and will add no vignetting.

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Post by ChrisR »

Marisano wrote:Nikon 135mm 2.8 AI and use it as the tube lens
I've tried Nikkors 135mm f/2.8 and 135mm f/3.5. I don't remember pixel-peeping one against the other, but they're both good. No vignetting on a Canon APS. (A 100mm Series E f/2.8 was less good than a 105 micro.)
You often see eg Zuiko 135mm (f/3.5 ??) camera lenses very cheap, I mean a very few Dollars/Pounds/Euros! They're nice & small, and easy to mount. I haven't tried one of those.

Cunha
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Cunha »

Hello, my camera is the Fujifilm GFX50R. In addition to using the entire sensor, it has a 35mm Mode. Is there any possibility to use this lens with this sensor? Thanks.

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Re: Infinity objective on low-end zoom telephoto works fine

Post by rjlittlefield »

Cunha wrote:
Mon Nov 28, 2022 9:18 am
Hello, my camera is the Fujifilm GFX50R. In addition to using the entire sensor, it has a 35mm Mode. Is there any possibility to use this lens with this sensor? Thanks.
I assume that you're asking about using the microscope objective. Yes, that can be done.

For use with your medium format camera, I suggest a setup like shown at https://www.photomacrography.net/forum/ ... hp?t=35350 , using a Raynox DCR-150 on extension tubes as necessary to reach infinity focus. The Raynox DCR-150 in that setup plays the role of the telephoto that began this thread. It serves to finish the image formation after the microscope objective has done the heavy lifting of making a subject that is actually small and close look like a subject that is huge and far away and thus can be imaged with a long lens focused at infinity. These days (now 12 years after the start of the current thread) you can buy pre-assembled kits such as https://www.wemacro.com/?product=raynox ... e-lens-pro , which includes the lens and tubes threaded to fit a standard M42 adapter for your camera mount.

The DCR-150 approach is surely not the best of all possible solutions, but it is known good for use with full-frame sensors.

To completely cover medium format, see https://www.photomacrography.net/forum/ ... hp?t=32346 for a discussion of other options for tube lenses.

--Rik

Cunha
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Cunha »

Hi Rik,
yes I meant the Nikon objective from your original post.
In fact, I want to find out if I can have better quality with an objective than with my Canon MP-E 65mm; the pros and cons of each solution and if I can go a little further than the x5, so I've been researching and this Nikon has appeared in articles and videos, with an affordable price.
Thanks for the tips and links I will check.

Sym P. le
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Sym P. le »

I believe the objective will easily outperform the MP-E 65 in the center but unknown away from center. I use a Nikon TU Plan and the results are stunning across the field, at least in terms of my expectations. The objective shown in this thread will have a smaller image circle.

The question is what do you want to achieve, image stacking or individual frames in situ? High power objectives are great for image stacking as the depth of field is traded for high resolution. Variable lenses trade resolution for versatility in composition. Personally, I love the challenge of the thin depth of field to compose in situ imagery but that isn't what most go for. Large sensors require a significant amount of content to fill an image. That may not be much of an issue for shooting broad flat surfaces such as silicon wafers but it becomes more challenging in 3D real life where you only need as much sensor real estate as your subject demands.

If you intend to do some in situ shots, the objective can allow easier access to the subject. With a 10x objective, I have only gone with as much magnification as a 135mm host lens provides (approx. 6.5x). Remember, with the objective you don't have the ability to stop down to buy back depth of field as you can with the MP-E 65. Link Beyond that, in terms of magnification, the shake factor has put me off. It all depends upon the pain you are willing to endure for the results you desire. The more extreme, the more unique the results.

I hope this helps. I have never regretted my objective purchase. It's a whole new level of spectacular.

Cunha
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Cunha »

Hello Sym, thanks for your message. I've been using the MP-E and other macro lenses for 15 years, but I've never been interested in microscope objectives; for no particular reason.

I don't do stacking and prefer images with just a few focus zones and the rest I leave to the imagination. My work is above all aesthetic.

I realized from what I've been reading that the objectives, in addition to allowing greater magnification and the discovery of "deeper worlds", can surpass MP-E in IQ. I still don't understand if I can use a lens in magnification steps (example x5, x7, x10) with the same objective or if I have to have several.
MP-E in this regard is practical.
I don't know if I should opt for a tube or a GF lens to attach the objective. I think it depends on the objective (Finite/Infinity).
The usage problems you indicate are important; I will take that into account.
But I am still at the beginning of this subject. I've been reading Robert O'Toole's website and Allan Watts' videos. Other suggestions will be welcome. Maybe this is not the topic to insert my needs; so I apologize.

Sym P. le
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Sym P. le »

Although infinity objectives are optimized for a given tube lens focal length, any lens can act as a host and IQ is stunning across a wide range of host focal lengths. The physical aperture of the host determines the image circle, i.e. f4 on a 50mm host is a smaller image circle than f4 on a 100mm or 135mm host. A zoom lens can be used although they will have their own sweet spots for IQ in terms of focal length and aperture and carry extra bulk. Compact setups are valuable in the field.

Generally, magnification is proportional to the focal length of the host. Wider hosts provide lower magnification and greater depth of field at the cost of image circle.

In other words, one infinity objective can be stepped through a variety of magnifications by utilizing different host lenses with the draw back of greater vignetting at lower magnifications.

Cunha
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Cunha »

Thanks a lot Sym. I own the gf 2/110mm, gf 4/120mm macro and Zeiss 2/100mm makro-planar. Usable? What about a zoom like the gf 5.6/100-200mm? Thanks 🙂

Scarodactyl
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Scarodactyl »

Sym P. le wrote:
Tue Nov 29, 2022 11:10 am
Wider hosts provide lower magnification and greater depth of field at the cost of image circle.
The focal length of the tube lens has no effect on depth of field. It is possible to increase depth of field by stopping down the tube lens but you'd have to go a ways for it to be the limiting aperture and I don't think it would be advisable for photography.

Sym P. le
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Re: Infinity objective on low-end zoom telephoto works fine

Post by Sym P. le »

The focal length of the tube lens has no effect on depth of field.
Is that the science of the matter or is it just that depth of field is minute with any tube length? I quickly ran a few tests and still believe that there is more dof with a shorter tube however my setup was not nailed down enough to declare it as fact. I just want to have an open mind with the equipment before saying something doesn't work. It just may not be an optimal setup for a different circumstance or even where it is used on a lark (figuratively, not ornithologically or combatively). Some lenses that I own produce truly awful results against my expectations and I regret purchasing them. Using my infinity objective on any length tube does not fit into that category even with vignetting.

Cunha, the fact is that an infinity objective attached to your equipment will produce an image and a expressively [sic] good one at that, at least in the middle. If you buy an econo objective, you will get a smaller image circle than if you get a larger diameter objective. If you mount the objective on a shorter focal length lens, you will get a smaller image circle than if you mount it on a longer focal length tube, and if you stop down the tube, you will again get a smaller image circle. I'm not intending to build your expectations to unrealistic levels. The longer and heavier the setup, the more of a struggle it is in the field and the more likely it becomes relegated to a lab situation. Your camera sensor has a ton of real estate. Even using the 35mm mode is a heap of space to fill when you have a miniscule dof. If you like whats in the center, than all is good. If you want to fill the frame, that's a different matter. You might find more enjoyable results using a reverse mounted lens or a reverse stack setup. You will get plenty of resolution in the center plus a full edge to edge image.

For what I enjoy, I picked up a Pentax Q-S1 with limited real estate but higher density pixels, which a high powered objective can still adequately light up for some interesting results. I would be curious to use a large format camera but I'm to engrossed in tighter spots, up close and personal with the insects and plants. Good luck and I look forward to seeing some of your results.

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Re: Infinity objective on low-end zoom telephoto works fine

Post by rjlittlefield »

Sym P. le wrote:
Tue Nov 29, 2022 10:06 pm
The focal length of the tube lens has no effect on depth of field.
Is that the science of the matter or is it just that depth of field is minute with any tube length?
Changing the focal length of the tube lens has no effect on the subject-side NA of the optics. So, if you are in the regime where the imaging system is limited by diffraction then there is no effect on the DOF because diffraction-limited DOF is determined by NA. However, if you reduce the magnification enough to move into the regime where the imaging system is limited by sensor resolution, then you effectively allow a larger acceptable circle of confusion on the subject side and that does increase the DOF even at constant NA.

--Rik

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