topic Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III in Gear Guide

Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

JOE929 — Wed, 29 Jul 2026 03:46:41 GMT

Hello, I’m currently shooting with the original 7D with an original EF100-400 L. I love this camera and it has treated me well. I primarily shoot air shows for my personal use. I am looking to upgrade and am looking for advice about image quality. I have rented the 5d mkiv and the IQ is so much better than the 7D. The issue is that it’s slower than the original 7D. I was considering the 1dxmkii or even the 1DXmkiii. Used they are about $1000 difference between the two. With the iii having a slight advantage with more focus points and a newer processor. Is the IQ of these cameras similar to that of the 5Dmkiv, albeit with less MP? I was also looking at the R6mkii, however, I heard that the original EF100-400 doesn’t work well with the mirrorless cameras. This would require me to add a new lens as well. Is there an appreciable difference in IQ vs the 1DX cameras? I don’t mind spending more money to replace camera and lenses, I’m just on the fence as to what’s best for my needs. I don’t want anything higher, such as a R5, I would have been satisfied with the 5Dmkiv if only its shutter speed was faster, but would like full frame over a crop sensor like the R7. I only plan to shoot with the mechanical shutter to avoid the jelly blob (so I read) as I’m mostly panning my shots. Thank you for your thoughts.

Re: Image quality

shadowsports — Wed, 29 Jul 2026 03:43:08 GMT

Greetings ,

Please provide your actual budget, including if you want to stay with DSLRs or migrate to mirrorless. You may have more options than you think. This will help us make better suggestions.

Re: Image quality

JOE929 — Wed, 29 Jul 2026 12:00:46 GMT

I don’t really have a set budget but don’t need to spend money because I can. My concern with mirrorless is the lens that I have(100-400L mki) won’t work very well, and have to purchase the RF100-500, which would double the cost. I’m just looking at my options. Should mirrorless be the best option, I could go that route. I don’t want the R5 series as it’s more than I want to spend with the 100-500. Thank you

Re: Image quality

shadowsports — Wed, 29 Jul 2026 13:22:36 GMT

Greetings,

This is basically what you said in your original post. No R5, etc... You obviously have a budget. Whatever that is?

Lenses are the real investment in photography. Your 100-400 is a lens released in 1998. It will be a gating factor regardless of the body (newer or old) it's mounted on. If you mount it on a 1Dx mkIII, it is not going to be able to take advantage of all of the features and performance offered by this body. I would view this more as an incremental upgrade with limitations. What is my opinion, i think the lens is ready to be retired. It won't be long before you're ready for another upgrade. What is a less expensive alternative?

Lens only: A Tamron or Sigma 150-600 G2 or C.

Body and Lens: 1Dx mkIII and either of those lenses. If you want to spend more money, A full frame mirrorless body and Canon adapter with one of those lenses.

Your current shooting system is 1998 and 2009. Just about anything would be an upgrade. If you're going to consider the 1Dx series, the mark III would be worth the additional cost. Primary reasons are number of focus points, AF algorithms, and the type of storage media it uses. CF Express B. If you buy an older camera with older storage technology you will buy twice. If you buy a camera that supports newer storage technology, you'd be able to take with you. At some point you will likely buy a mirrorless body.

As you step up in Canon's lineup, you're not just buying more megapixels. You're also buying features and a user experience. Things that make life as a photographer easier. If you'd like to save some money buy Canon refurb or used.

Your lens would be the first thing I'd part with.

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

wq9nsc — Wed, 29 Jul 2026 13:54:01 GMT

I shoot sports, primarily with a pair of 1DX III bodies, but I still have the pair of 1DX II bodies I used prior to the three.

The AF system in the III is marginally better than the II and there is a slight increase in quality at moderately high ISO (above 12,800) but it is slight. I still use the 1DX II bodies a lot for casual stuff. All of the 1DX series are incredibly robust and reliable, something I can't say for the R-1 that I have tried twice to love and both times the bodies glitched during an event which has never happened with hundreds of sports events shot with my 1DX bodies.

As others noted, the lens is critical and you will lose some "reach" going from the 7D to a full frame but you have already experienced that when you tried the 5D series so if that experience was OK, you will love a 1DX II or III. AF is precise and fast and the 1DX bodies will handle any kind of weather you throw at them including extreme heat and will do so with long battery life.

No matter what body you end up with, long term also think about a lens with enough reach. These were some casual shots of a hummingbird that got my attention while I was adjusting the PH in the pool. Shot with 1DX III and EF 800 f5.6 handheld in 95 degree very high humidity weather. I was sweating, the 1DX III wasn't 😂

Rodger

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

wq9nsc — Wed, 29 Jul 2026 16:40:57 GMT

I guess Canon has a limited time to edit a post so I will add this link as a separate post. These are some photos I took at a neighbor's business four years ago. Cameras and lenses used were a 5DS with Canon EF 70-200 f2.8, 1DX II with Sigma 150-600 (Smugmug for some reason shows this as a Sigma 70-200 lens but it properly displays the actual focal length), and a 1DX III with the EF 800 f5.6 lens.

I originally bought the Sigma 150-600 as a light lens for hiking but I have been very impressed with how well it works.

Smugmug link to crop spray copters in action: https://rodgersingley.smugmug.com/Helicopters-July-28-2022/n-b2nXKx

Rodger

Re: Image quality

JOE929 — Thu, 30 Jul 2026 03:19:42 GMT

Thank you Rick, I knew that my lens was an older design but was unaware of just how bad it was. With your comment about adding those lenses to a full frame mirrorless would be better, are you saying that a mirrorless body such as the R62 is better than the 1dx’s?

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

JOE929 — Thu, 30 Jul 2026 03:23:37 GMT

Thank you for the examples Roger. Your helicopter images are extremely clear. Since you have both the 1dxm3 and R6m2, which do you like better for action? Since my lens is outdated, am I better off going mirrorless with an RF series lens?

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

wq9nsc — Thu, 30 Jul 2026 13:42:24 GMT

Hi Joe,

I don't have a R-6. I have tried both the R-3 and R-1 on several occasions and I just prefer the handling and performance of my 1DX III bodies to the current mirrorless offerings. But the R series may be perfect for you so it is best that you try one if possible.

The current mirrorless bodies just don't fit my shooting style and taste. Reliability and performance are my most important criteria and the 1DX III shine on those features. They are an extremely rugged and refined design after many generations of 1 series DSLR bodies. I shoot sports in snow, pouring rain, extreme heat, etc. and the 1DX bodies have never let me down and have never had any sort of glitch or other abnormal behavior which I experienced when I tried to love the R-1 series. At some point, I am sure the R-1 will become as stable as its predecessors but when I tried them on several occasions they weren't there yet.

Functionality has to come first and features become important only after the base functionality is 100% there, something Microsoft has forgotten in the operating systems market and I hope that Canon isn't going down the same road. For me, a camera system is something I don't want to think about at an event because I want to focus on the action. My 1DX III bodies and L series primes are something I don't think about during the action, they have never stuttered, locked up, or needed a battery change during an event even in weather that was terrible.

I also shoot with at least two and sometimes three bodies and lenses at an event and I don't want to have to worry about an exposed sensor getting zapped by sunlight or a laser. With a DSLR, the sensor is only exposed at the point of capture while with a mirrorless system the sensor is always exposed during operation since it is also driving the focusing system. And personally, I don't like staring at a video display during a long sports event because I much prefer the optical system. So again, those are my personal preferences and others have very different preference factors and weights.

Other than a 4K camcorder and the little Canon M6 Mark II I bought purely for casual travel (and of course my iPhone) I don't own any other mirrorless gear. The little Canon M6 is great for airline trips and I just got back from hiking with my daughter in Taos a couple of weeks ago where it worked fine and was perfect for me going from the 600 foot altitude of central IL to doing some hiking above 12,000 feet in the NM Rockies. I missed the performance of my 1 series bodies and their lenses but I didn't miss the weight since I didn't have time to acclimate before hiking; fortunately I run 10 to 12 miles every other day so hiking went well. The little M6 Mark II provides a good compromise between a phone camera (I despise them given the responsiveness of my 1 series gear) and the big 1 series bodies. I am on my second M6 Mark II because my daughter tried it while I was driving us to a hiking spot on Mt. Hood while she was in her undergrad program and she was amazed at how much the small simple camera could do that her iPhone couldn't. I was happy to donate it to the cause 🙂

What I dislike about mirrorless may not be a factor for you; that is why choice of camera bodies, lenses, and accessories like harnesses/straps are a personal choice. At some point, I MAY make the change to mirrorless but it will be only after the benefits greatly outweigh the drawbacks for what I do. And at that point since I would be changing lens systems also, I will definitely take a close look at Nikon and Sony and the winner for me will be which corporation has the best combination of reliability and performance under the conditions I shoot.

Rodger

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

shadowsports — Thu, 30 Jul 2026 14:39:24 GMT

I wanted to wait for Roger to reply again. One thing worth noting, the sensor is covered on the R6 mkII and above when changing lenses 😉. This is true when using electronic or mechanical shutter. So this is not a concern.

@JOE929 , you asked. 1Dx vs R6 mkII. "Better" is partially subjective.

From an objective standpoint. The R6mkII offers 24 MP vs 20 MP, 4,897 focus points vs 191, IBIS, and superior subject-tracking autofocus. The 1Dx mkIII offers high reliability, rugged build quality and extreme battery life. While the mirrorless body is superior on paper, there are people out there who love the build quality, performance and battery life of a 1Dx series body. Worth noting mirrorless bodies are also extremely reliable. Everyone has their preference.

What one user might choose, might not be right for another photographer. For example, my colleague Rodger would choose a 1Dx body in every situation (just about) 😂. He has shot beautiful images in all types of shooting situations, weather, etc and has never been let down. He loves the balance and feel of a larger body coupled with a heavier lens. Performance and reliability is paramount. I would choose an R6 mkII, he would choose a 1Dx series. He's personally and financially invested in this platform. I'm invested in mirrorless and RF glass.

Your situation is a little more unique. The age of your gear allows you the opportunity to go in either direction. In many situations, the EF to RF adapter allows you to continue using your older lenses on a newer mirrorless body. This reduces the initial capital expense. However, in your case, the lens you're using most is extremely old. It's not a bad lens, It's just from an era that's been surpassed from a technology standpoint.

So, working within the constraints of your budget, your current needs and what you anticipate your future needs to be. You can decide whether sticking with a DSLR or migrating to mirrorless is the right move for you. If you own other (more current) EF glass sticking with a DSLR might make sense. Or you can adapt these lenses to a more modern mirrorless body. In many cases, these lenses will perform better than they ever did on a DSLR. Some cases but not all.

Since lenses are the primary investment, you need to decide what is best for you. I've already made some suggestions at various price points. Also refurb or used. Photography is not an inexpensive hobby. I understand why you are struggling with this decision. If you ultimately see yourself going to the RF 100-500, I'd go with a mirrorless body, and one of the interim EF lenses I suggested. This will help ease your capital expense. If you'd be happy at 20.1 MP, not having an articulating screen and see yourself staying with this platform for the foreseeable future then a 1Dx series body would be great. Keep in mind that availability and support for DSLRs and EF glass is shrinking. There are plenty of used lenses out there that will be available for the foreseeable future. Parts, service and repair will become more challenging as time passes.

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

johnrmoyer — Thu, 30 Jul 2026 15:08:26 GMT

Since you seem to like EOS 7D, have you considered EOS R7? An ornithologist acquaintance uses it and gets very good photos of birds.

I use EOS R5 with EF100-400mm f/4.5-5.6L IS II USM +2x III and adapter.

Not an aircraft, but flying (hand held and panning ) : https://www.rsok.com/~jrm/2025Nov25_Salt_Plains_NWR/2025nov25_crane_IMG_5042c.html

Sandhill Crane (Antigone canadensis) at Salt Plains National Wildlife Refuge in Alfalfa County, Oklahoma, United States on November 25, 2025

Camera Model Name	Canon EOS R5
Lens Model	EF100-400mm f/4.5-5.6L IS II USM +2x III
Focal Length	800 mm
Exposure Time	1/800
ISO	1000
F Number	13.0
Camera Temperature	26 C
Measured EV	13.88
Measured EV 2	29.5
Focus Distance Upper	114.01 m
Focus Distance Lower	81.91 m

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

SignifDigits — Thu, 30 Jul 2026 17:07:58 GMT

If it were me, and today, and for air shows, on something of a budget and not needing the daily reliability of the DSLRs, I would recommend refurbed R6 Mark ii and a refurbed RF 200-800 for better reach over the 100-500. Or keep the EF 100-400 on a Canon adapter and rent and try the 200-800 vs 100-500 until you decide. I've had to replace the MF dial on my R6 Mark II and I'm not a daily pro but a hobbyist so I can see why some might have reliability concerns. You CAN set up the R6 Mark II to have the sensor exposed during lens changes, but that is not the default setting.

Of course both are available as refurbs today and I feel that refurbished is better than new since the unit has been individually tuned and hand-tested.

As John points out the APS-C is a good way to go to get longer reach, so those are options, as well. Air shows I don't think you'd need the IBIS in the R7, and I prefer the R10 controls better at a lower price point.

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

JOE929 — Fri, 31 Jul 2026 10:25:43 GMT

Thank you for the advice. I’m not sure which way to go. I am more undecided now, it seems that the 1dx’s are solid work horses but the R6’s are the future. Either way, I’m looking at over $5k(refurbed)for a new setup. I want the best bang for the buck, with sharper images. I honestly don’t expect to upgrade again as I plan to retire in a few years. The 7D works great, just need more fps to miss less shots. Thank you

Re: Image quality, looking to upgrade to EOS-1D X Mark II or EOS-1D X Mark III

SignifDigits — Fri, 31 Jul 2026 11:52:24 GMT

Whatever you do, in my opinion, CAREPaks should be added to your budget. Newer gear is newer and higher tech and more tech is in them so more things to go wrong. I didn't buy one for my R6 Mark II and just spent over $500 on a repair, which, likely would have paid for the CAREPack and I'll still have it under warranty. I've bought them for other items, but my cameras have all not had issues in the past, so I gambled and lost.