Nikon Z in infrared / full spectrum

[ScottyRae]

Got quite a few questions about Nikon Z cameras in full spectrum / infrared. I use a Nikon Z5 converted to full spectrum to shoot mostly landscapes, and using Kolari clip in filters, having upgraded from a Hoya R72 which I've had for many years.  I've previously used D7100 and D90 converted to 720nm IR.  I've read and contributed to one of the old Z threads regarding what I guess is the PDAF correction issue, which I obviously suffer from, but that was a couple of years back and I've only just managed to get back onto the forum.  Most of my questions are related to the PDAF correction issue.

 

Firstly, have there been any significant improvements, patches or methods of processing Nikon Z RAW images over the last couple of years to improve the PDAF correction issue?  I'm guessing not, but I thought I'd ask...!  I tend to process for higher contrast, which I think makes the issue more prominent?   I've been using Denoize AI, which does an acceptable job of removing the banding 

 

Secondly, any improvement in other models of Nikon Z camera, particularly the Z8 or Z9?  (I think I read the Z7 / Z7II might be worse?  So guess that isn't a consideration? )

 

Anyone willing to share any RAW images from any of these models that I could compare to mines?  Ideally 720nm but I'm not going to be too fussy!   

 

The second set of questions if probably more lens related.  Some of the more important Z lenses seem to be really prone to hotspot, but I've got a Z7 as my colour body so having to balance my requirements...  I've sold all of my old F mount lenses now too, though haven't sold the FTZ yet.  

 

I bought the Z5 and 24-200 kit, which seemed a great idea given how well my 18-200 worked on my D7100 infrared!  It's a great general purpose lens and covers the zoom ranges I want to use most, but alas the 24-200 hotspots badly.  So I ended up using the 24-70 F4 with my Z5 rather than my Z7, and put the 24-200 on my Z7 - feels like I'm not using my best lens on my best camera here....  I've since bought a 14-30 F4 and the 100-400 - both of which seem fine.  However adding a 2X Teleconverter to the 100-400 brings hotspots with it.  I also just bought a 24-120 F4 to try out, possibly as a replacement for my 24-200 (better glass on my main body vs less reach / utility... hmm...) but it hotspots at wider zooms.  I've got an option on a Z 70-200 F2.8 at a good price, but again I hear it hotspots (which sucks because the F mount VRII was great on my D7100!)   

 

If you shoot 2 bodies of which one is colour, what would you do here lens wise?  Send back the 24-120, sell the 24-200, keep or get rid of both?  Do something else?  

 

So one obvious question, given I'm using Kolari filters is, how well does their hotspot killer clip in filter work?  Anyone know?

 

Obviously that would then totally destroy my ability to use other clip in filters - it's feeling like I might have made a mistake going clip in, though a lot cheaper than screw ins, especially as my largest lens is 82mm!     

 

Feel like I'm at a bit of a crossroads with my photography in general, and infrared in particular, and not really sure where I'm going kit or processing wise.  Would really like some thoughts / input!  Thanks! :)  

[photoni]

I also have a Z7 a Z5 (as a backup)
For UV and IR I took an old Sony A7 (400€) + the basic modification to remove the two cut filters (in a Sony center only 120€) and I'm happy!
.
I was thinking of converting the Z5 to FS (but I saw that it has PDAF problems like the Z6 and Z7) I think it's more logical to sell it, and opt for an old Sony A7R since it doesn't have these problems and works well with UV and IR and with a modification with a quartz I keep the focus
LINKS
 

UV photography is mostly static, with tripod; while for IR photography it is better to have the camera modified directly with an internal 720 or 830 nm filter, so you don't lose focus and you can use it "by hand"

 

for lens hot spot issues, this is a cool SITE

 

.
PS. if you sell the 24-120 f4 Z at a good price I'm interested :)

Thanks

Toni

[Lou Jost]

3 hours ago, photoni said:

I also have a Z7 a Z5 (as a backup)
For UV and IR I took an old Sony A7 (400€) + the basic modification to remove the two cut filters (in a Sony center only 120€) and I'm happy!
.
I was thinking of converting the Z5 to FS (but I saw that it has PDAF problems like the Z6 and Z7) I think it's more logical to sell it, and opt for an old Sony A7R since it doesn't have these problems and works well with UV and IR and with a modification with a quartz I keep the focus
LINKS
 

UV photography is mostly static, with tripod; while for IR photography it is better to have the camera modified directly with an internal 720 or 830 nm filter, so you don't lose focus and you can use it "by hand"

 

for lens hot spot issues, this is a cool SITE

 

.
PS. if you sell the 24-120 f4 Z at a good price I'm interested :)

Thanks

Toni

The A7R might be a good solution for the OP, but in case other people come here to look for solutions, I want to mention that the Sony A7R has a huge shutter-shock problem under some conditions. If you are doing close-up or especially microscopy with it, it can be unusable at moderate shutter speeds like 1/15-1/60.

[ScottyRae]

Thanks Toni, appreciate your input! :)  I do still have my D7100 720nm, so I could go back to that, or convert it to full spectrum, though I've got no lenses for it any more.  However I've just invested so much in Z now though... :/

 

And on the 24-120, it was an Amazon Prime purchase, so can send back without losing anything.  However they had it for just over £900, which is cheaper than I've seen it anywhere - cheaper than some used prices!

 

 

[nfoto]

Most Nikkor Z lenses do hot spot in IR. The 28/2.8 SE is much better than the others, however. I use it a lot.

 

I still often rely on my F-mount optics for IR. Some of the Laowa and Viltrox lenses can do IR quite well, too, even in Z mount.

[photoni]

1 hour ago, Lou Jost said:

Sony A7R has a huge shutter-shock problem

 

I don't know this problem, does it also occur with electronic shutter?

 

.

2 hours ago, ScottyRae said:

And on the 24-120, it was an Amazon Prime purchase

 

I sold the "bad" 24-120 f:3.5-4.5 with F mount
then I also sold the "mediocre" 24-120 f:4
I've heard good things about the Z version
but on Prime I see it at 1,250-1,350 € non 900£ !!!
 

[Lou Jost]

Unfortunately the A7R has no fully electronic shutter. You need an A7R2 or higher for that. But sadly those are hard to convert to FS because they have an IR diode inside; the original A7R does not have that diode.

Also many Sonys, including the A7R, always compress their RAW files using lossy compression (a crazy idea), and in addition, many have long-exposure RAW noise reduction that can't be turned off. These are all much-discussed issues on forums and blogs; see especially Jim Kasson's work and also many posts in the astophotography community, where these issues are fatal. The noise reduction issue is referred to as the "star eater".

 

[nfoto]

For those still able to use F-mount lenses either natively on the camera or through adapters, the vintage Zoom-Nikkor 28-45mm f/4.5 combines a low asking price with excellent IR rendition. The manual zoom 35-70mm f/3.5 (62mm filter thread) is also very good, and usually the even lower priced 35-135mm f/3.5-4.5 delivers excellent IR images as well. For wider views, the 20mm f/3.5 either the 72mm UD model or the smaller 52mm version, can be recommended. For third-party optics, look for the Panagor 21mm f/4.

[photoni]

@Lou Jost  OT today I got another A7 at 300€ (not A7r)

.

Nobody wants a Z5 with 24-50 zoom? (1800 shots)

[ScottyRae]

Going back to my questions, whilst I've got great answers on the lenses, I guess the 3 that haven't been answered are:

 

Any better ways of processing out the PDAF correction banding?  Or is Denoize still as good as anything?

 

are any of the other Nikon Z cameras any better?  Or worse?  

 

Anyone got any experience of the Kolari Hotspot Killer clip in filter?

 

and on the lenses, someone suggested just getting another 24-70 F4.... which seems crazy (I mean why would you have 2 of the same lens?) but then.... they're relatively cheap even new!  Suggested I could then use the saved money to get the 70-200 F2.8, but....  Not sure I'd do that if I can't use it on both cameras, and I've got the 100-400 in that range. 

 

(Oh, and Toni, surprisingly the 24-120 is currently £899 on Amazon in the UK!   

[Andrea B.]

I don't know if anyone here is using converted Zs for UV/IR. Especially not the expensive Z8 or Z9. So you probably won't get an answer for how to correct PDAF banding or converting the Z8 or Z9.

 

Maybe we should just google a question about correcting PDAF banding? I'll see what I can find. 

[Andrea B.]

Jason Odell, a well-known Nikon user & writer, has the following two pages, both of which would be very useful to you and other Z conversion users (if we have Z conversions here, aside from Birna maybe?). I was really quite happy to find Jason's lens lists!! 

 

Nikon Z-Mount Lenses - Ranking for IR Hotspots. https://luminescentphoto.com/blog/nikon-z-infrared-lens-performance-chart/

• Jason makes a point in his comments which I also wanted to mention. When checking any lens for hotspots, be sure to run through all the apertures. Some apertures can be less hotspotting than others. The tendency seems to typically be that hotspotting gets worse as you stop down. (Does anybody have any comments on that?)
• Also, when checking a zoom lens for hotspots, you also need to run through several basic focal lengths to check whether hotspots occur at longer or shorter focal lengths (or for all focal lengths!).
• Jason also lists some hotspot results for F-mount lenses on a Z body using the FTZ adapter.
• Jason and his friend tested for IR hotspots using a 720 nm filter on a Nikon Z6 body. Whether or not results would change when using other filters, I do not know. (This would be a good test area for someone who had the time to set up a good test.)

 

PDAF Banding Removal using Surface Blur & Masking in Photoshop. Does not appear to be very difficult.

https://luminescentphoto.com/blog/2020/07/22/how-to-fix-banding-in-digital-images/

 

Scotty, I hope those links are helpful to you.

[Andrea B.]

Both the Z8 and the Z9 use PDAF so they will produce banding under some conditions.

[nfoto]

I was puzzled by some of the observations of IR hot spotting on Z lenses, referred to earlier. In general nearly all Z Nikkors don't do well in IR. The exception is 28/2.8 SE (listed as 'poor '...), and 35/1.8 (agree on that one if the lens isn't stopped down too much).  The long 400/4.5Z is OK if you keep the apertures larger than f/11 which is reasonable for a long lens any way.

 

However, there are lots of non-Nikkor lenses which can be used on the Z systems and do a good job in IR. Perhaps I should do a write-up? Time permitting, of course.

[Andrea B.]

https://www.photoartfromscience.com/single-post/kolari-vision-infrared-camera-anti-reflection-coating-review

 

Edward Dozier, whose blog is named Photo Art from Science, has tested Kolari's anti-reflection IR conversion and found it to make a huge difference in preventing unwanted reflections and hotspots. His test was done with a Nikon D7000 590 nm conversion. Kolari's AR coating was applied to the internal 590 nm IR-pass glass used in the conversion.

[Andrea B.]

Birna -- I would say that Jason Odell's list is very kind to the Nikon Z-mount lenses. "Mild center brightness" is mentioned for several lenses he ranks as "Very Good". So I think that you and Jason would definitely not agree on the definition of "Very Good". 

 

In Jason's list only 3 lenses are listed as having "No discernible hotspots":    24/1.8S, 50/1.8S, 100-400/4.5-5.6/VR/S.

 

Of those 3 lenses, I'm thinking the 50/1.8S could be very useful for general IR photography on a Z.

 

[ScottyRae]

Given I went all in on Z, lenses are a big dilemma for me as I don't really want / it really seems a waste to have any lenses that only work on 1 camera.  When I bought my Z5 with the 24-200 kit lens, I doubt there was much info on how Z lenses were performing, but I obviously very quickly found it hotspotted.  However the 24-70 F4 that I bought for my Z7 didn't.  I don't think.... maybe it's just within my tolerance and I've not noticed.... 

 

I was planning on doing some lens (sharpness, etc) testing on my colour Z7 this weekend before I decide whether to send the 24-120 back (I think the answer will be yes for the above reasons.... but I've already got lenses that only work on one camera, so...).  I might as well test them again on my Z5 as well and I'll post the results.  Another reason to send the 24-120 back is the new Tamron 35-150 F2-2.8....!      

 

and thanks for the info on the Kolari coated pass through Andrea - given I've invested in clip-in filters, the only viable option I'd have would be to see whether they would provide the glass to the UK camera conversion company I use.  Might get in touch with Kolari anyway - they've been helpful in the past.  

[Andrea B.]

Well, for now, make complete experiments (all apertures, all focal lengths) with what you have and keep good notes about those apertures and lengths which reduce hotspots in IR.

 

• You might want to experiment with lens hoods to determine whether they help mitigate hotspots. Lens hoods prevent some of the off-axis light from entering the lens. For example, the Coastal Optics 60mm UVIR lens has hotspots in a certain magnification range which can be controlled through the use of an extra long lens hood.

 

• Also, you might want to try an AR-coated, clear filter on the lens as a means of reducing hotspots. I don't know of any experiments here using such a filter, but it makes sense. Although front filters can sometimes induce flare or reflections when shooting directly into the light source. (So don't do that, lol !!)

 

With the exception of certain specialist lenses, the camera and lens manufacturers do not, of course, cater to the UV or IR photographer. We are always using cameras & lenses outside their original specifications. So it takes some time and lots of experiments to determine what works best for UV/IR needs.